爆裂玉米

… The popcorn used in this study was a commercial sample of yellow popcorn maize distributed by Topco Associates, Inc., Skokie, Illinois. After purchase, it was stored in a sealed …

… popped grains of popcorn maize and sorghum has been examined by light and scanning electron microscopy. In both cereals, popping … contents expand during popping. Despite this, …

… Popcorn (Zea mays L.) is a special type of maize that pops up when heated leading to … popping rate and flake volume is not well understood. The cross made between high popping …

… There are not many programmes which emphasise popping ability in maize in Africa … of popcorn is not given as much attention as dent maize. In South Africa, the only record of popcorn …

… The accuracy of reseach has been showed to create relation groups each other and rich variations in terms of features studied on popcorn genotypes, because the maize plant has an …

Objective: To assess the effect of popping thermal treatment on the physical and structural properties of Toluqueño creole popcorn maize (Zea mays L.) Design/methodology/approach: Toluqueño creole maize and commercial (Zea mays L.), as a control, were subjected to three popping treatments: hot oil, hot air and microwave. Moisture, popping yield, textural properties (hardness, gumminess, chewing), and structural features (size: area, perimeter) by image analysis were determined. Results: The results showed that the treatment by hot air in commercial maize presented the best pop yield, reaching a value of 71.88%, while the microwave treatment was the best for Toluqueño maize, with 12.93% of expansion yield, because its low moisture content (8.42 ± 0.29%). The best textural characteristics for both types of maize were obtained after applying the hot air treatment, resulting in soft, low rubbing and good chewing for all samples. The microstructural analysis in Toluqueño maize treated by microwave evidenced the presence of spherical starch granules, which was attributed to a low gelatinization degree. Also was possible to observe highest intergranular space, which was related to a less compactation grade and consequently less hardness in the raw grain (without expansion). Limitations on study/implications: High resolution and improved methodologies to observe the starch grain and components distribution could be result in a better description of the effect of thermal treatment in the maize grains. Findings/conclusions: The treatment by hot air was the best process to obtain popcorn for all samples, being the commercial maize who presented the best physical and structural features.

Mycotoxins are secondary metabolites that are produced by molds during their development. According to fungal physiological particularities, mycotoxins can contaminate crops before harvest or during storage. Among toxins that represent a real public health issue, those produced by Fusarium genus in cereals before harvest are of great importance since they are the most frequent in European productions. Among them, deoxynivalenol (DON) and fumonisins (FUM) frequently contaminate maize. In recent years, numerous studies have investigated whether food processing techniques can be exploited to reduce the levels of these two mycotoxins, which would allow the identification and quantification of parameters affecting mycotoxin stability. The particularity of the popcorn process is that it associates heat treatment with a particular physical phenomenon (i.e., expansion). Three methods exist to implement the popcorn transformation process: hot air, hot oil, and microwaves, all of which are tested in this study. The results show that all popping modes significantly reduce FUM contents in both Mushroom and Butterfly types of popcorn. The mean initial contamination of 1351 µg/kg was reduced by 91% on average after popping. For DON, the reduction was less important despite a lower initial contamination than for FUM (560 µg/kg). Only the hot oil popping for the Mushroom type significantly reduced the contamination up to 78% compared to unpopped controls. Hot oil popping appears to provide the most important reduction for the two considered mycotoxins for both types of popcorn (−98% and −58% average reduction for FUM and DON, respectively).

… grain properties of popcorn related to its popping ability, the mechanism of popping and the … A unique helical screen arrangement causes the popped maize to be removed from the …

… Popcorn is a snack food with significant commercial popularity. Popcorn popping mechanics … The most important quality traits for popcorn are expansion volume and “eatability” factors, …

Popcorn is a specialty corn with worldwide popularity as a snack. Despite having great market demand, genetic improvement in popping quality is limited, which is caused by the limited germplasm utilization and narrow genetic base. An assortment of diverse germplasm, their effective characterization, and integration into popcorn breeding pipeline is the foundation for an efficient breeding program. Here, kernel characteristics, popping quality traits, and agro-morphological traits were evaluated across three locations on a diverse panel of 48 popcorn inbreds derived from diverse landraces and populations of exotic and indigenous origin. The variations due to genotypes, locations, and genotype × location interaction were highly significant. The popping quality traits recorded wide variation with a high coefficient of genotypic determination. The kernel dimensions, kernel density, test weight, and grain yield were negatively correlated with popping quality traits. Genotypes with rice-type kernels exhibited better popping quality than pearl-type kernels. Analysis of genotype × location (G×L) interaction identified two target locations for the key popping quality trait, popping expansion volume. PMI-PC-175, PMI-PC-187, PMI-PC-188, and PMI-PC-189 were identified as superior genotypes over checks for desirable popping quality, agronomic performance, and high grain yield. The contrasting inbreds for popping quality and flake shape (mushroom vs. butterfly) can be utilized for developing mapping populations to enhance our understanding of molecular aspects of popping quality traits. Further, the promising inbreds can be utilized in the genetic improvement of popcorn and crossed to develop superior popcorn hybrids. The results suggest a potential opportunity to establish an efficient popcorn breeding program.

The aim of the present study was to evaluate the sensory, nutritional and popping qualities of two types of popcorn grains (Zea mays, L.) yellow and purple popcorn under different methods of expansion. Popping processes applied were: in a pan with oil, in an electrical popper with and without oil. The purple popcorn is superior in protein (12.56%), crude fiber (3.58%) and ash content (1.89%), whereas yellow popcorn has 10.84%, 2.27%, 1.03% for protein, crud fiber and ash content, respectively. Obviously, the higher the preference for the tasters was the popcorn produced by the electrical popper with oil, for both yellow and purple popcorn. The carotenoid content increased when popping with oil was applied on contrary to popping without oil. The highest content of anthocyanin could be traced in unexpanded purple popcorn, but decreased with the different forms of popping process. Yellow and purple popcorn grains had 1.19 and 1.58 mg of gallic acid / g sample, respectively and significant increase was figured out in the total phenolic availability after popping in pan with oil in both yellow and purple popcorn. The expansion volume of yellow and purple popcorn by the same expansion method was insignificant, but significantly different from those expanded with and without oil.

… Popcorn (Zea mays everta) is a special type of flint maize that boasts several unique popping … Water-limiting conditions strongly influence the major popcorn quality attributes: expansion …

… popping process, different IR power (350, 450 and, 550 W (W)) in the different distances (10, 20 and, 30 cm) on some physicochemical characteristics of popcorn … popping yield, popping …

… ABSTRACT The popping performance of 18 popcorn hybrids was studied … popping quality indices between the 2 microwave treatments, indicated a negative effect of salt on popping …

… content and popping methods on popping quality of five popcorn genotypes were … highest popping quality, ie popping volume, flake size and the lowest percentage of unpopped kernels…

The objective of this study was to characterize the effect of hybrid and environment on physical and chemical characteristics of popcorn kernels that have shown importance in predicting …

… All of the factors included in this research, such as kernel type, moisture level, kernel size and popping method, were effective on popcorn quality parameters. But the effects changed …

… popping quality and suitability for popping, and the sensory properties of the popcorns were evaluated. A popcorn … kernel sizes in terms of their popping quality and sensory properties. …

… Therefore, in this study only damage to the side of the popcorn kernel was studied. Kernels … good idea to popcorn processors of the importance of quality control in relation to damaged …

… The model that explains why popcorn pops is … popcorn kernel acts as a pressure vessel. A tough, continuous outer layer called the pericarp encloses the contents of a popcorn kernel, …

Abstract Upon popping, corn kernels undergo substantial dehydration. Initial moisture content of the kernel, popping method and temperature determine the final quality, and physical characteristics of the flakes. In this work, corn kernels (Zea Mays var Everta) at different moisture contents were subjected to hot-air popping and quality, physical and morphometric parameters of the flakes were evaluated, and related with their microstructural features. The best moisture content for hot-air popping was 9.14%. Macro and microstructural examination and digital image analysis of the flakes showed that, at the macro level, the roughness of the different flakes, as given by their fractal dimension (FD), were similar among morphologies, whereas at the microscale, it was possible to differentiate between them. Additionally, at the macro-scale, for the different morphologies high correlations were found between areas and the linear dimensions (Feret or width)FD of evaluated flakes. Moreover, when using the FD of the microstructures as the exponent, high correlations were also observed, which confirms an analog multiscale behavior between the roughness of the flakes and their microstructures.

… The adjusted equation for popcorn kernel popping expansion capacity data as a function of the EC submitted to different impact duration times at the initial storage period is given by (2) …

… influencing popcorn popping quality. Devel. Food Sci. … Optimum popping moisture content for popcorn kernels of different … Effect of kernel size and genotype on popcorn popping volume …

Abstract Chapalote is a Mexican ancient maize landrace with popping characteristics that have not been studied. This work aimed to study the kernel physicochemical properties and their relationship with popping properties of 10 Chapalote accessions. Two popping methods, cooking pan and hot-air popping, were tested. A commercial popcorn sample was used for comparison purposes. Hot-air popping led to higher expansion volume, less unpopped kernels, and bigger popped kernels than traditional popping. Among Chapalote samples, one accession (612) had the best popping properties, but none of them popped similarly to the commercial popcorn. This behavior may be related to the non-breeding origin of Chapalote accessions contrasting with the improved hybrids. Smaller kernels containing more pedicel, pericarp, and vitreous endosperm led to higher expansion volume and lower unpopped kernels. In air-popping, higher α-zein content, and bigger starch granules with less crystallinity influenced positively the popping properties, mainly the air bubbles and popped kernel size. Pericarp thickness was not a crucial factor in popping performance. Some Chapalote accessions with good popping quality could be an important source of germplasm in breeding programs for the development of modern popcorn varieties with distinct properties, which may help to avoid the extinction of this landrace.

… enhance the quality of the popcorn and accordingly consumers’ satisfaction. In this study, experiments were conducted to discriminate the popcorn kernels which could be popped from …

… of the specialty corn, their genetics, and scope of enhancing the nutritional quality traits in the specialty … The selection of Pr1 and Booster1 (B1) in popcorn breeding has succeeded the …

Popcorn (Zea mays spp. mays - Everta) is an ancient and widely recognized maize type, of American origin, enjoyed for centuries worldwide and still highly valued for its unique popping trait. Italy, considered a secondary center of maize differentiation, still holds a rich diversity of local maize landraces survived on farm and also ex situ stored. Despite this genetic wealth, Italian popcorn varieties have largely been neglected in modern breeding programs and remain poorly characterized, with only fragmented and incomplete data available. Recent studies have confirmed the widespread presence of traditional popcorn landraces across Italy, also if relegate to small garden cultivations, yet a comprehensive understanding of their genetic and agronomic traits remains lacking. This underscores the urgent need to preserve and document these landraces to conserve biodiversity and protect Italy’s cultural heritage. In response to this gap, in this study, ten Italian popcorn landraces were collected and morphological characterization was performed. Moreover, a genetic characterization of 282 individuals was conducted using a GBS approach. The morphological characterization revealed significant phenotypic and agronomic variability for a total of 13 traits including susceptibility to fungal infection and popping traits, whereas the genetic one identified 313,342 SNP variants, uncovering evidence of local adaptation and provided insights into population structure by Admixture analysis, which revealed the presence of 8 ancestral populations consistently with morphological and historical data. This work sheds light on these neglected landraces, offering valuable information for biodiversity conservation and future breeding efforts, particularly in marginal areas where smallholder cultivation remains crucial.

Popcorn is a food highly appreciated throughout the world, generating billions of dollars annually just in the North American market alone. Even in the face of the historical superiority of American hybrids, which occupy almost 100% of the grain production fields in Brazil, our researchers have been working to develop cultivars that combine important traits for the crop, such as tolerance to leaf diseases and high rates of grain yield and popping expansion. This work investigated the degree of genetic divergence among 40 diallel hybrids of popcorn, 16 parents and 6 elite controls using mixed models to discriminate superior materials to be adopted in the Brazilian agribusiness. Based on the individual Best Linear Unbiased Prediction (BLUP) of each of the 15 variables analyzed, the Unweighted Pair-Group Method using Arithmetic Averages (UPGMA) and Tocher clusters were performed, and the study of Pearson correlation was carried out. The results pointed out that there is genetic variability among the genotypes evaluated and that the best candidates for composing superior genotypes are in the combination between the P10×L77 parents and/or between the P7 and L88 lines. Linear correlations showed that earlier flowering and taller genotypes exhibited an association with materials more tolerant to Exserohilum turcicum intensity.

Popcorn consumption in Brazil has grown significantly over the years, and genetic improvement is essential to obtain sustainable gains in multiple traits to supply this increasing demand. Thus, the objective of this review was to contribute information concerning the process of popcorn breeding in tropical regions, germplasm availability, popcorn breeding plans, the main characteristics related to popcorn quality and yield, and advances and perspectives in the process of popcorn improvement. The main focus of breeding programs is to obtain hybrids from inbred lines with high popping expansion (40 mL g-1) and yield (4.000 kg ha-1). The genetic improvement performed in Brazil has presented significant advances, mainly due to work developed in public institutions with the development of new hybrids that present more significant popping expansion and yield. However, the number of cultivars is still low, and most of them are controlled by private companies. Therefore, intrapopulation methods are recommended to develop open-pollinated varieties with high popping expansion, and this trait can be used as an early predictor of promising inbred lines to obtain superior hybrids for grain quality. Furthermore, popping expansion can be quickly recovered in backcrosses involving the cross of common maize with an inbred popcorn line.

… from a cross of popcorn and field corn lines were … genes involved in kernel endosperm development and metabolic processes were identified and these all can be explored in popcorn …

… of this study were to assess the genetic diversity and population structure of popcorn germplasm, which represent the genetic resources currently used in Chinese popcorn breeding. …

BACKGROUND Popcorn is the most popular specialty maize and it makes a significant contribution to the Indian and global economies. Despite perfect exploration of heterosis in field corn, progress in popcorn breeding remains constrained due to its narrow genetic base, leading to a significant dependence on imports. In this study, 15 landrace- and population-derived inbreds from temperate and tropical germplasm were crossed with five testers, which are the parents of superior popcorn hybrids, in a line × tester mating design. RESULTS Significant variation was observed in popping quality and agronomic traits among crosses evaluated across three locations representing diverse maize-based agro-climatic zones in India. Additive genetic variance governed the traits related to popping quality, whereas dominance variance was responsible for the agronomic traits. In addition to significant heterosis specific to certain traits, we identified promising crosses that exhibited superior performance in both popping quality and grain yield (GY). The genotype + genotype × environment (GGE) biplot methodology identified PMI-PC-104 and PMI-PC-101 as the best discriminating testers for popping quality traits and Dpcl-15-90 for GY. Lines PMI-PC-205, PMI-PC-207, and PMI-PC-209 were the best general combiners for popping quality traits and GY. The heterotic groups identified based on GGE-biplots and the magnitude, direction and stability of combining ability effects would serve in the development of competitive popcorn hybrids for a sustainable popcorn market. CONCLUSION Using the additive nature of popping quality traits and the dominant nature of GY, recurrent intrapopulation selection can be employed to derive desirable popping quality inbreds with high GY for genetic enhancement. Desirable popping quality alleles from novel germplasm can thus be combined with high-yielding domestic elite inbreds to establish a sustainable popcorn breeding program. © 2024 Society of Chemical Industry.

… Brazilian popcorn populations have reduced heterosis and genetic variability to popping expansion in relation commercial cultivars; there is genetic variability among Brazilian popcorn …

Popcorn lines with genetic resistance to foliar diseases allow the production of higher yields at lower costs. Thus, the development of resistant genotypes becomes essential, while the selection efficiency of parents and hybrids depends on the existence of genetic variability and knowledge about the genetic trait control. The objective of this study was to determine the genetic merit of the hybrid lines and genotypes, as well as the reciprocal effect; to draw conclusions on the genetic control of the traits of disease incidence and severity associated with resistance to Exserohilum turcicum, Bipolaris maydis, Puccinia polysora and of the agronomic traits grain yield and popping expansion; and to assess the effects of the trait interrelations on parent and hybrid selection. Fifty-six hybrid combinations (F1 and reciprocal crosses) were evaluated in two growing seasons. A randomized block design with four replications was used. Regardless of the growing season, the non-additive genetic component had the greatest influence on the studied traits, whereas no reciprocal effect was observed. The performance of lines L61, L70 and L76 was good in both growing seasons by increasing the level of multiple disease resistance associated with high gains in GY and PE. The hybrids L61 x L76; L61 x L77; L76 x P1 were the most promising of the tested crosses for cultivation in both seasons, targeting a decrease in the levels of several diseases and higher grain yields and popping expansion.

… In addition to these components, popcorn also contains … The pericarp, the layer of the popcorn kernel, likewise contains … the microstructure of both the kernel and pericarp of popcorn. …

… The objective of this study was to evaluate the effects of pericarp color and expansion … quality of popcorn kernels. Popcorn kernels with red, white or yellow pericarps underwent …

… cell wall components of the kernel pericarp that may control the rate of moisture loss in popcorn during microwaving. Inherent properties of pericarp were investigated in a number of …

Expanded popcorn grain is widely consumed as a healthy snack all around the world; however, the study of the behavior of its components by processes such as nixtamalization is scarce. Therefore, the aim of this work was to characterize the nanomechanical, structural, and antioxidant properties of nixtamalized popcorn grain pericarp. FT-IR results showed that the secondary structure of proteins of the nixtamalized pericarp was α-helix with 42.10%, the turn was 21.5% and 36.33% β-sheet, and proteins of the pericarp did not present the random coil structure. Pericarp showed antioxidant activity, as their values were 550.1 ± 2.9 and 44.2 ± 1.6 (TE)/mL for ABTS and DPPH, respectively; total phenols content was 0.21 ± 0.008 (TE)/mL; reducing power values were around 29 to 31%; hydroxyl radical scavenging ranged from 36 to 55% and iron chelation around 115 to 140% compared to the standard acids. Thickness values of the nixtamalized pericarp by SEM image analysis were 0.15 ± 0.1 mm near the pedicel inferior tip, 0.07 ± 0.01 mm at middle, and 0.03 ± 0.02 mm at upper of the grain. Young’s modulus value was 261.72 ± 23.58 MPa with a Gaussian function fitting at the distribution of all values. This research provides novel and valuable information for understanding the nanomechanical and protein arrangement, as well as and the antioxidant activity of nixtamalized popcorn grain pericarp in order to promote other processes and uses for this kind of pericarp maize.

The popping expansion is a characteristic that is positively related with the quality of popcorn. A positive correlation between the volume of expansion and the thickness of the pericarp, and between the proportion of the opaque/shiny endosperm and the grain weight and volume, were postulated. However, there are no reports in the literature that address the importance of cell wall components in the popping expansion. Here, we investigate the biochemical composition of the pericarp cell walls of three inbred lines of popcorn with different popping expansion. Inbred lines GP12 (expansion volume >40 mL g−1), P11 (expansion volume 30 mL g−1) and P16 (expansion volume 14 mL g−1) were used for the analysis and quantification of monosaccharides by HPAEC-PAD, and ferulic and p-coumaric acids and lignin by HPLC. Our hypothesis is that the biochemical composition of the pericarp cell walls may be related to greater or lesser popping expansion. Our data suggest that the lignin content and composition contribute to popping expansion. The highest concentration of lignin (129.74 μg mg−1; 12.97%) was detected in the pericarp cell wall of the GP12 inbred line with extremely high popping expansion, and the lowest concentration (113.52 μg mg−1; 11.35%) was observed in the P16 inbred line with low popping expansion. These findings may contribute to indicating the quantitative trait locus for breeding programs and to developing other methods to improve the popping expansion of popcorn.

Physical properties of kernels, grains, and seeds are necessary for the design of equipment to handle, transport, process and store the crop. The physical properties of popcorn kernels …

The formation and development of maize kernel is a complex dynamic physiological and biochemical process that involves the temporal and spatial expression of many proteins and the regulation of metabolic pathways. In this study, the protein profiles of the endosperm and pericarp at three important developmental stages were analyzed by isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with LC-MS/MS in popcorn inbred N04. Comparative quantitative proteomic analyses among developmental stages and between tissues were performed, and the protein networks were integrated. A total of 6,876 proteins were identified, of which 1,396 were nonredundant. Specific proteins and different expression patterns were observed across developmental stages and tissues. The functional annotation of the identified proteins revealed the importance of metabolic and cellular processes, and binding and catalytic activities for the development of the tissues. The whole, endosperm-specific and pericarp-specific protein networks integrated 125, 9 and 77 proteins, respectively, which were involved in 54 KEGG pathways and reflected their complex metabolic interactions. Confirmation for the iTRAQ endosperm proteins by two-dimensional gel electrophoresis showed that 44.44% proteins were commonly found. However, the concordance between mRNA level and the protein abundance varied across different proteins, stages, tissues and inbred lines, according to the gene cloning and expression analyses of four relevant proteins with important functions and different expression levels. But the result by western blot showed their same expression tendency for the four proteins as by iTRAQ. These results could provide new insights into the developmental mechanisms of endosperm and pericarp, and grain formation in maize.

The mechanical resistance of the popcorn pericarp has a positive and direct relationship to its expansion volume. It allows enough time for the endosperm to gelatinize completely before its extravasation. Expansion is a polygenic trait that has been extensively studied. However, no records in the literature indicate proteins that directly affect pericarp thickness and integrity. Therefore, the present work aimed to identify candidate pericarp proteins associated with the expansion capacity of popcorn kernels using the shotgun proteomic approach. The analyses were carried out in the pericarp of two popcorn inbred lines, P11 (expansion volume of 30 mL g-1) and P16 (expansion volume of 14 mL g-1), in two developmental stages (15 and 25 DAP). A total of 803 non-redundant proteins were identified. Most of them were involved in key processes associated with pericarp development and thickening. Two candidate proteins stood out among the differentially abundant proteins. Peroxidase was up-accumulated in P11/25 DAP (high popping expansion) and was 1.498 times more abundant in this inbred line, while xyloglucan endotransglucosylase/hydrolase was more abundant in P16 (low popping expansion) in both developmental stages. Thus, the peroxidase protein increases expandability, whereas xyloglucan endotransglucosylase/hydrolase decreases it, even though its specific role has not been elucidated. These proteins should be further investigated, as they may be used to improve expansion capacity in popcorn breeding programs.

Popcorn, one of the world's most popular snack foods, represents the most ancient type of maize domesticated by humans. However, the genetic basis underlying popcorn evolution and kernel‐popping traits remains largely unknown. In this study, we assembled a high‐quality genome sequence of the popcorn landrace Strawberry Popcorn (SP) and conducted extensive population genomic analyses. The SP genome spans 2.3 Gb and harbours a large inversion on chromosome 8, along with millions of genetic variants that enable the discovery of beneficial alleles. Translocations and substantial duplications of the Ga1 gene occurred in the locus associated with unilateral cross‐incompatibility on chromosome 4. Tandemly duplicated Ga1 genes underwent pseudogenisation and truncation with complete loss of gene function. The P1 gene experienced gene expansion and regulatory modifications, leading to downregulation of transcription and subsequent loss of pericarp colour during maize domestication and improvement. Population genomic analysis further identified a subset of 12 marker genes from over 2494 genes under human selection, which were reshaped to enhance kernel‐popping traits during domestication. These marker genes include Pl1 and Dek1 for pericarp and aleurone layer thickness; THP9, Sh2, SUS1, Smk10, KW1, O7, and NKD1 for protein and starch biosynthesis; and VP5, CCD7, and Crti3 for carotene biosynthesis, which all influence endosperm vitreousness, a key factor determining kernel hardness for popping. Among these genes, KW1 and O7 stand out as pivotal genes with a significant impact on kernel‐popping performance. These results provide a wealth of gene targets to greatly accelerate the molecular breeding of improved popcorn varieties.

EnglishPopcorn (Zea mays var. everta) has a higher commercial value than common maize, in addition to being a popular food among consumers. Today, there is a constant search for cultivars with superior performance for several traits of interest in the case of popcorn, yield and popping expansion. On this basis, this project proposes to characterize progenies of popcorn with different values of expansion capacity regarding chemical composition and micromorphology. Kernels from the fifth cycle (C5) of intrapopulation recurrent selection were evaluated. The progenies were selected based on the popping expansion volume of their kernels. The kernels were quantified for amylose and analyzed for starch granule arrangement and pericarp thickness by scanning electron microscopy. Progenies with low popping expansion volume (0 and 7 mL g-1) showed amylose contents of 21.24 and 20.18%, respectively; a less compact endosperm, with individual starch granules interspaced with empty spaces; and pericarp thickness between 40.94 and 38.99 µm, respectively. By contrast, progenies with high popping expansion volume (30 and 35 mL g-1) showed amylose contents of 23.92 and 26.10%; a vitreous endosperm; more-compact starch granules without empty spaces in between; and pericarp thickness between 107.66 and 107.84 µm. Progenies with higher popping expansion volume exhibited a thicker pericarp, a high amylose percentage and a more-compact endosperm, whereas those with the lower expansion volumes showed a thinner pericarp, a lower amylose percentage and individual starch granules. portuguesO milho-pipoca (Zea mays var. everta) tem um valor comercial mais elevado do que o milho comum e e um alimento popular entre os consumidores. Hoje, existe uma constante busca por cultivares com desempenho superior para os diversos caracteres de interesse, no caso da pipoca, produtividade e capacidade de expansao. O trabalho propoe caracterizar progenies de milho-pipoca com diferentes valores de capacidade de expansao quanto a composicao quimica e micromorfologia. Foram estudados graos do quinto ciclo (C5) de selecao recorrente intrapopulacional. As progenies foram selecionadas com base nos valores de capacidade de expansao de seus graos. Os graos foram quantificados para amilose e analisados quanto ao arranjo dos grânulos de amido e espessura do pericarpo por microscopia eletronica de varredura. Progenies com baixa capacidade de expansao (0 e 7 mL g-1) apresentaram teor de amilose de 21,24 e 20,18% respectivamente; endosperma menos compacto, com grânulos de amido individualizados e intercalados com espacos vazios; e espessura do pericarpo medindo entre 40,94 e 38,99 µm, respectivamente. Por outro lado, progenies com alta capacidade de expansao (30 e 35 mL g-1) apresentaram teor de amilose de 23,92 e 26,10%, endosperma vitreo, sendo os grânulos de amido mais compactos e sem espacos vazios entre eles; e espessura do pericarpo medindo entre 107,66 e 107,84 µm. Progenies com altos valores de capacidade de expansao apresentam maior espessura de pericarpo, alta porcentagem de amilose e endosperma mais compactado, enquanto as com menores valores de expansao, apresentam menor espessura do pericarpo, menor porcentagem de amilose e grânulos de amido individualizados.

… Information on expansion volume of popcorn genotypes using both popping methods is not … type X popping method interaction for expansion volume and its components in popcorn. …

… is the most important quality trait in popcorn (Zea mays L.), … ) responsible for popping expansion volume in a popcorn × … markerassisted selection for popping expansion volume. Of 259 …

… air popping test was performed with an Arçelik popcorn popper … samples were used for expansion volume. Subsequently, the … Popping was continued until there were 5 s between pops. …

… elastic deformation were evaluated as indicators of the popping characteristics of microwave popcorn. A greater expansion volume was observed in varieties having sphericity values …

… Popcorn is often sold by volume, at locations such as movie … final popped volume for a given initial popcorn weight … predictor of expansion volume in conventional popping. The …

… The objectives of this study were to 1) develop methods of measuring density and popped volume of individual popcorn kernels and 2) investigate the effects of hybrids and physical …

… ABSTRACT Improvement of expansion volume, defined as the volume of popped corn per … the most important objective of popcorn (Zea mays L.) breeding programs. Popcorn, however, …

Response surface methodology was used to evaluate the effects of ingredients on popcorn popping characteristics. The effects of different ingredients on the expansion volume and unpopped kernel ratio of popcorn in a conventional popper and a microwave oven were evaluated and optimized by response surface methodology. The regression models were significant and had R2 value in the range of 0.919–0.956. The optimum levels of ingredients for microwave popping were 4.4% salt, 5.9% vegetable oil, 0% sodium bicarbonate and 16.4% butter, this formulation giving an expansion volume of 33.1 mL g−1. In the case of conventional popping, the maximum expansion volume of 37.3 mL g−1 was obtained for 3.5% salt, 6% vegetable oil, 0.10% sodium bicarbonate and 12.9% butter.

… including popcorn, dent, and flint corns. Expansion volume is the most critical quality factor for pop… of a variety of parameters on popping volume and popping time. Several studies have …

… Popping expansion volume (PEV) is the most important quality trait in popcorn, while its … between a dent corn inbred Dan232 and a popcorn inbred N04, were evaluated for their PEV, …

Popcorn bursts open, jumps and emits a ‘pop’ sound in some hundredths of a second. The physical origin of these three observations remains unclear in the literature. We show that the critical temperature 180°C at which almost all of popcorn pops is consistent with an elementary pressure vessel scenario. We observe that popcorn jumps with a ‘leg’ of starch which is compressed on the ground. As a result, popcorn is midway between two categories of moving systems: explosive plants using fracture mechanisms and jumping animals using muscles. By synchronizing video recordings with acoustic recordings, we propose that the familiar ‘pop’ sound of the popcorn is caused by the release of water vapour.

… The main objective of this project was to determine the effects of high relative humidity (85%) and high temperature (35C) on mold invasion and popping quality of popcorn stored in …

… and temperature of the barrel zone on whole grain in extruded whole grain products were explored. The color look is improved by the reduced moisture levels and greater temperatures. …

… the pericarp, but not so slow that the available moisture leaks out before the kernel reaches the popping temperature and pressure [Figure 14.3 (C)]. The correct moisture for popcorn …

… In microwave oven popping temperature is affected by power used and power absorption by the kernels which in turn depend upon the dielectric and thermophysical properties of the …

… In this sense, the diallel analysis can be used as one suitable tool for … inbred popcorn, eight from a tropical climate and one from a temperate climate, for seed quality, agronomical traits …

… Among the strategies that enable success for this purpose, diallel crosses and analyses are … few studies of popcorn, especially studies that focused on seed quality traits linked to grain …

… -QTLs by meta-analysis across three … traits in popcorn. The results obtained from our experiments could provide valuable information for improving kernel composition traits in popcorn …

… (Zea mays L.) is a special kind of corn type being used to make popcorn flake for a … popcorn. According to classical quantitative genetics and traditional statistical analysis, Popping traits …

Abstract The popularity of popcorn as a snack is on the rise and it is now widely consumed across the globe. A study was conducted on 23 popcorn lines in a Randomized Complete Block Design (RCBD) in the research field of the National Maize Research Program (NMRP), Chitwan, Nepal to determine variability for popping ability in popcorn genotypes, grain yield, genetic parameters and study relationship among agronomic and popping quality traits. The popping percentage ranges from 58 percent (Australia Thulo Dana (Y)) to 92.67 percent (Bhimnagar local) and Flake Volume ranged from 82.67 cm3 (Pop45/pool-17) to 403.35 cm3 (Bhimnagar local). Means for grain yield ranged from 2.21 t/ha (popcorn Y + W (w)) to 5.39 t/ha (Pop45/pool-17). As a result, the improvement of popcorn should focus on identifying lines with an acceptable level of popping ability while also improving their grain yield and yield attributes. Pop45/pool-17 produced a higher grain yield whereas Bhimnagar local and Jumle show high popping ability. So these genotypes could be used for future popcorn breeding programs. Overall, this research highlights opportunities for further breeding progress in popcorn maize through selective breeding techniques.

Water deficit is the main limiting factor in rainfed agricultural production, negatively affecting germination and vegetative development. The objectives of this work were to characterize inbred lines for drought tolerance, to identify the most important root and shoot morphological traits for discriminating genotypes, to compare the efficiency of identifying contrasting inbred lines using uni- and multivariate methods, and to evaluate the effectiveness of identifying drought-tolerant genotypes at seedling and vegetative stages. We assessed 28 popcorn inbred lines and three maize single crosses, two drought-tolerant and one drought-sensitive. At the seedling stage, drought was induced on germitest paper moistened with polyethylene glycol 6000. At the vegetative stage, we applied water stress using lysimeters. We measured root and shoot morphological traits under water stress and no stress and processed the relative values. Uni- and multivariate methods, alone or in combination, were equally efficient for identifying contrasting inbred lines for drought tolerance. The confidence interval and Dunnett’s test worked very well when contrasting controls were included. Principal component analysis allowed to discriminate genotypes and identify the most important traits for discriminating them. At the seedling stage, inbred line 22-1824-2 was the most drought-tolerant and 22-1877-3 the most sensitive. At the vegetative stage, inbred lines 22-1920-1 and 22-1867-4 were the most tolerant and 22-1860-5 was the most sensitive. Root length, volume, dry weight, and surface area, as well as water content, were the most important traits for discriminating genotypes. Due to distinct tolerance mechanisms, drought tolerance should be assessed at both stages.

Low rainfall rates are becoming increasingly frequent because of climate change, causing droughts and threatening world food security. For popcorn, drought is the most limiting abiotic factor for plant’s growth and development. Thus, the water deficit directly impacts for crop productivity. Based on knowledge of the genetic basis of traits involved in stages of popcorn germination and seedling development under water stress, genotypes with potential for adaptation to adverse growing conditions can be selected early. Therefore, data on genetic effects and combining ability of 10 popcorn parents were compiled to propose breeding strategies for the development of cultivars with greater adaptation to water stress in the early stages. Forty-five diallel hybrids were evaluated under two different water regimes, that is, water stress and full irrigation. This corresponded to a water retention capacity of 25% and 70% of the germination paper. The plants were watered daily as needed for seven days. A range of factors were evaluated, that is, germination traits including the germination speed index and germination on the seventh day; shoot traits including length and dry weight; and root system including length, dry weight, root-to-shoot ratio, maximum root number, root network area, specific and root network length, and root volume. Breeding for drought adaption in the early stages of popcorn development can be successful when hybrids are used, because of the genetic effects of dominance (ϕs). These control the traits evaluated at the seedling stage. The combinations L61 x P2 and L71 x P3 were recommended, in view of the more successful performance estimated for traits related to the shoot and root system.

Fusarium ear rot (FER) is a disease that causes a decrease in grain quality in several popcorn fields in tropical regions. To contribute to the development of popcorn cultivars resistant to FER and superior in the main agronomic traits, the study aimed to compare gains in popping expansion (PE), grain yield (GY), and FER resistance through direct and indirect selection strategies by proposing a new super trait. The study was conducted in Campos dos Goytacazes, RJ. The traits were evaluated in 41 inbred lines from four environments using a randomized block design with four replicates. Six selection strategies and four selection intensities were tested. Direct selection on GY resulted in losses in PE and small gains in FER in the majority of the environments. Positive selection on PE resulted in FER reduction in scenarios of lower selection intensity. Selection by popping volume showed a satisfactory increase in GY and PE but was not effective in FER reduction. Selection by multi‐trait genotype–ideotype distance index resulted in GY increase only in some environments, PE increase in all environments, and FER reduction in all environments under higher selection intensities. The newly developed super trait popping volume without Fusarium (PVwF) showed the possibility of increasing GY (32.90% at 88.8%) and PE (5.10% at 10.20%) while simultaneously reducing FER in all environments and selection intensities (−6.30% at −6.70%). PVwF is an easily executable methodology to help popcorn breeders optimize gains in their programs. The lines L214, L217, L292, and L328 are more suitable for use in mating blocks aimed to develop superior popcorn hybrids.

The Spodoptera frugiperda, is one of the most deleterious pests of popcorn and the identification of resistant genotypes is determinant in breeding programs. The objective of this study was to select popcorn genotypes resistant to S. frugiperda and the key traits related to the identification of resistance. The popcorn varieties UEM J1, Composto Márcia, Arachida, Composto Gaúcho, and Zapalote Chico (resistant check) were evaluated in a completely randomized design with 100 replications. The experimental unit consisted of one Petri dish, containing plant material and a caterpillar The following traits were evaluated: larval stage duration (LSt), food intake weight(IW), final larva weight (FW), mean larva weight (MW), feces (F), assimilated (A) and metabolized food weight (M), relative consumption rate (RCR), relative metabolic rate (RMR), relative growth rate (RGR), conversion efficiency of ingested food (CEI), apparent digestibility (AD), conversion efficiency of digested food (CED), and leaf area consumed (LAC). The diagnosis of multicollinearity, analysis of canonical variables, genetic divergence, hierarchical clustering, factor analysis and canonical correspondence analysis were carried out to perform multivariate analysis. After the multicollinearity test, the traits FW, IW, RCR, AD, and LAC were maintained for further analysis. The traits IW, FW and AD were determinant in the resistance by antixenosis expressed by the varieties Zapalote Chico and Arachida, for the varieties Composto Gaúcho and Composto Márcia the determining characteristics were RCR and LAC and for the variety UEM J1 the variable LAC showed greater importance. Variety Arachida was considered resistant to S. frugiperda by antixenosis and can be used in the future as a source of favorable alleles to breed resistant popcorn hybrids. The traits relative consumption rate, apparent digestibility and leaf area consumed were considered key traits in the identification of resistance against S. frugiperda in popcorn genotypes.

The evaluation of popcorn lines for salt stress during the germination phase facilitates the early selection of superior genotypes, ensuring crop success. This study assessed 31 lines to identify genotypes tolerant to salt stress in the early phase and to understand the effects. Seeds were sown on paper substrate with two concentrations of sodium chloride: zero (NS) and 100.0 mM (SS), in a randomized block design with four replicates of 25 seeds each. Physical and physiological traits of seeds and seedlings were evaluated. Analysis of variance revealed significant effects (p ≤ 0.01) for genotype, salinity condition, and their interaction. Genetic variability was observed under both conditions. In NS, area and germination were the most influential factors in differentiating lines, while in SS, total seedling length and the percentage of abnormal seedlings were key. The stress tolerance index identified lines L263, L684, L472, and L358 as the most tolerant, and lines L690, L217, L220, and L213 as the most sensitive. Tolerant genotypes are potential candidates for crossbreeding aimed at developing hybrids adapted to salinity conditions, promoting agricultural sustainability in adverse environments. The significant interaction between genotypes and salinity conditions reinforces the importance of conducting selection in specific stress environments.

Abstract Favorable agronomic traits are important to improve productivity of popcorn. In this study, a recombinant inbred line (RIL) population consisting of 258 lines was evaluated to identify quantitative trait loci (QTLs) for nine agronomic traits (plant height, ear height, top height (plant height subtracted ear height), top height/plant height, number of leaves above the top ear, leaf area, stalk diameter, number of tassel branches and the length of tassel) under three environments. Meta-analysis was conducted then to integrate QTLs identified across three generations (RIL, F2:3 and BC2F2) developed from the same crosses. In total, 179 QTLs and 36 meta-QTLs (mQTL) were identified. The percentage of phenotypic variation (R2) explained by any single QTL varied from 3.86 to 28.4%, and 24 QTLs with contributions over 15%. Nine common QTLs located in the same or similar chromosome regions were detected across three generations. Five meta-QTLs were identified including QTLs in three independent studies. Seven important mQTLs were composed of 11–26 QTLs for 4–7 traits, respectively. Only 11 mQTLs were commonly identified in the same or similar chromosome regions across agronomic traits, popping characteristics (popping fold, popping volume and popping rate) and grain yield components (ear weight per plant, grain weight per plant, 100-grain weight, ear length, kernel number per row, ear diameter, row number per ear and kernel ratio) by meta-QTL analysis. In conclusion, we identified a list of QTLs, some of which with much higher contributions to agronomic traits should be valuable for further study in improving both popping characteristics and grain yield components in popcorn.

Climate change is expected to intensify water restriction to crops, impacting on the yield potential of crops such as popcorn. This work aimed to evaluate the performance of 10 field cultivated popcorn inbred lines during two growing seasons, under well-watered (WW) and water stressed (WS) (ψsoil≥ −1.5 MPa) conditions. Water stress was applied by withholding irrigation in the phenological phase of male pre-anthesis. Additionally, two contrasting inbred lines, P7 (superior line) and L75 (low performer) were compared for grain yield (GY) and expanded popcorn volume (EPV), selected from previous studies, were tested under greenhouse conditions. In the field, no genotype x water condition x crop season (G×WC×CS) interaction was observed, whereas GY (−51%), EPV (−55%) and leaf greenness (SPAD index) measured 17 days after anthesis (DAA) (> −10%) were highly affected by water limitation. In general, root traits (angles, number, and density) presented G×WC×CS interaction, which did not support their use as selection parameters. In relation to leaf senescence, for both WS and WW conditions, the superior inbred lines maintained a stay-green condition (higher SPAD index) until physiological maturity, but maximum SPAD index values were observed later in WW (48.7 by 14 DAA) than in WS (43.9 by 7 DAA). Under both water conditions, negative associations were observed between SPAD index values 15 and 8 days before anthesis DBA), and GY and EPV (r ≥ −0.69), as well as between SPAD index 7, 17, and 22 DAA, and angles of brace root (AB), number of crown roots (NC) and crown root density (CD), in WS (r ≥ −0.69), and AB and CD, in WW (r ≥ −0.70). Lower NC and CD values may allow further root deepening in WS conditions. Under WS P7 maintained higher net photosynthesis values, stomatal conductance, and transpiration, than L75. Additionally, L75 exhibited a lower (i.e., more negative) carbon isotope composition value than P7 under WS, confirming a lower stomatal aperture in L75. In summary, besides leaf greenness, traits related to leaf photosynthetic status, and stomatal conductance were shown to be good indicators of the agronomic performance of popcorn under water constraint.

The objective of this study was to estimate the direct and indirect effects of agricultural, morphological, physiological, and root traits of popcorn lines, under two conditions of water supply: full irrigation (FI) and drought stress (DS). A complete randomized block design with three replications was used to evaluate the following traits: expanded popcorn volume per hectare (EPV), 100-grain weight (100GW), mean ear length, mean ear diameter, number of grains per row (NGR), prolificacy (PRO), anthesis to silking interval, tassel length, number of tassel branches, plant height, shoot dry matter, green index (SPAD), and canopy temperature depression (CTD), root angle (RA), tap root volume (TRV), and crown root volume (CRV). Analyses of variance and path analysis, and subsequent partitioning of direct and indirect effects were performed. For the traits EPV, PRO, CTD, RA, CRV and TRV, the genotype x environment interaction was significant. Drought stress had significant effects on EPV (−7.15%), 100GW (−23.52%), SPAD (−29.31%), CTD (87.15%), RA (24.54%), and CRV (44.89%). The traits NGR and SPAD were found to be decisive for the expression of EPV. The exploitation of these traits by indirect selection is expected to induce increments in EPV in environments under DS and FI.

… popcorn genetic dissimilarity were available. The purpose of this study was to characterize the genetic profile of eight S 6 popcorn lines … in the popcorn breeding program carried out by …

The Brazilian popcorn has low genetic variability and the successful development of advanced lines, new popcorn cultivars with high grain yield (GY) and expansion volume (PE) is dependent on parental selection and precise determination of heterotic groups. The aim of this study was to evaluate genetic variability and identify heterotic groups in synthetic populations of popcorn, using diallel crosses. Thus, nine synthetic populations were crossed using complete diallel scheme. The GY and PE traits of 36 hybrids and reciprocals were evaluated in a randomized complete block design with 72 treatments and two replicates in two years. The effects of non-additive genes were the most important in the genetic control of these traits, indicating a favorable situation to produce hybrids. The reciprocal effect is mainly due to non-maternal effects for GY and PE. The highest GY values were obtained for the 02 x 08, 04 x 09, 05 x 09, and 01 x 09 crosses and the highest PE were obtained for the 07 x 01 and 03 x 04 crosses. The exploitation of synthetic populations from S 3 lines can be an alternative to increase the genetic variability for grain yield and popping expansion in popcorn breeding programs.

Drought currently affects several regions worldwide and tends to be more frequent due to climate change. It might compromise food security and the economic structure related to agribusiness. Popcorn has a crucial role in the Brazilian economy, but the cultivars that adapt to water stress, the most prejudicial abiotic stress for crop productivity, are unknown to date. This deficit of popcorn varieties adapted to heat and drought stresses will become more limiting with climate change. Given this scenario, knowing the genetic basis of agronomic traits under stress conditions is essential in promoting crop productivity and plant adaptation to abiotic stresses. Under two contrasting water conditions (WC) and different crop seasons (CS), we aimed to generate information about the combining ability of 10 popcorn progenitors and 15 hybrids through a partial diallel-mating design. The water stress was initiated at the male pre-anthesis stage. Significant genotype*crop seasons (G*CS), genotype*water condition (G*WC), and genotype*crop seasons*water condition (G*CS*WC) interactions were present. Regardless of CS and WC, non-additive effects controlled grain yield (GY), grain number per row (GN), ear length and diameter (ED), and 100-grain weight, while additive effects were present for popping expansion (PE). For each CS, regardless of WC, the cause-effect of GN (2018) and ED (2020) on GY seems to be an opportunity for indirect selection. Utilizing genetically broad-based hybrids is also a good opportunity for obtaining superior genotypes for GY and PE as it is possible to select inbred lines for both of these traits. We recommend the L76 × L61 hybrid for the Brazilian agribusiness context due to its greater productivity and dominance deviations.

The purpose of this study was to use microsatellite markers to evaluate the genetic divergence in 10 popcorn lines. The number of alleles per locus ranged from 2 to 5. The proportion of polymorphic loci was highest (50%) in line Curagua, while Zelia II was the most monomorphic (100%). The arithmetic complement of similarity of Roger and Tanimoto for the 10 lines indicated lower genetic similarity between the lines Zelia II and Avati Pichinga I and higher similarity between Zelia I and Zelia II. The mean distance between groups was greatest between the group formed by lines IAC 112 I 112 IAC II, Avati Pichinga I, Avati Pichinga II and the group containing Yellow Pear Popcorn II. Strategies on how to use the heterosis between different lines in partial diallel crosses are indicated.

… corn were made in 1943 including some of the same inbred lines of popcorn used in 1942, and additional good inbred lines from the popcorn breeding program. In the se"cond series of …

The poor yield and popping quality underscore the need for indigenous germplasm improvement. This study aimed to find parents with high general combining ability (GCA) and specific combining ability (SCA) for yield and popping traits. A Line × Tester design was used to hybridize 9 inbred lines and 4 testers, resulting in 36 hybrids. These hybrids were tested in field trials across three agro-ecologies of Nigeria in 2019 and 2020. Three replicates of 5 trials were set up in a Randomized Complete Block Design, and an air popper was used for popping tests. The study showed that crosses differed significantly at ρ≤0.01 for all agronomic traits except ears per plant (EPP) while the line × tester interaction was highly significant for all agronomic traits, except anthesis-silking interval and EPP. Parental lines V7, V9 and M3 had positive and significant GCA effect at ρ≤0.01 for grain yield, while V8, V9, and M3 were positive and significant at ρ≤0.01 for popping volume. Ten Hybrids had positive and significant SCA effect for grain yield and popping volume. Non-additive gene effects were more important in the inheritance of most agronomic studied traits, as evidenced by the line × tester interaction contributing a larger proportion (52 – 86%) to hybrid variance compared to the line effects (10.51 - 44.80%) and tester effects (0.20 to 15.24%).  The study identified parental lines V7, V9, and M3 as good general combiners, whereas M1×V1, M1×V3, M1×V4, M1×V6, M1×V7, M3×V4, M3×V5, M4×V7, M4×V8 and M4×V9 were considered for their superior specific combining ability across various environments, particularly for grain yield and popping volume.

Popcorn is a popular snack item worldwide. The genetic base of popcorn germplasm is quite narrow, which resulted in limited number of popcorn hybrids. Here, a set of sub-tropically adapted 39 popcorn inbreds of exotic- and indigenous-origin, were characterized using morphological traits and molecular markers for their effective utilization in hybrid breeding. Significant variation for grain popping percentage (GPP: 86.0-98.0%), percent popping expansion (PPE: 1493-3213%) and volume after popping (VAP: 210-315ml) was observed. The mean PPE (2069%) and GPP (93.6%) among popcorn inbreds were higher than the popcorn check variety, VL popcorn (PPE: 1739%, GPP: 92%). Positive correlations were observed among GPP, PPE and VAP. Molecular characterization using 72 SSRs produced 237 alleles with a mean of 3.3 alleles per locus. Polymorphism information content ranged from 0.05 to 0.68, while Jaccard’s dissimilarity coefficients varied from 0.27-0.82. Principal coordinate analysis also depicted diverse genetic nature of inbreds. Cluster analysis grouped the inbreds into three major clusters each having 16, 18 and 5 inbreds. Contrasting inbreds were identified for development of mapping populations to identify loci governing desirable popping quality. The study also identified potential heterotic combinations. The information generated here assumes great significance in breeding for popcorn hybrids.

Nine popcorn genotypes were assessed for eight traits and their genetic divergence was estimated by multivariated techniques to identify parents for inclusion in breeding programs involving hybridization. The nine genotypes were divided into two groups by the Tocher method using the generalized Mahalanobis distances. The popping expansion, popcorn size and grain mass per plant were considered the most important agronomic traits for selecting parents for crossing. Using the divergence and these trait scores as criteria for crossing, the crosses between genotype 9 (group II) and genotypes 8, 3, 7, and 5 (group I) were recommended. Therefore, only four (11%) out of 36 possible (diallel) crosses among the nine assessed genotypes would be made.

… GS in actual popcorn breeding populations have assessed the genetic gains for agronomic traits and the viability of this technique in comparison with traditional breeding techniques. …

Abstract One of the most important quality traits in popcorn breeding programs is the popping expansion (PE) capacity of the kernel, which is the ratio of the volume of the popcorn to the weight of the kernel. In this study, we evaluated whether near infrared spectroscopy (NIR spectroscopy) could be used as a tool in popcorn breeding programs to routinely predict and/or discriminate popcorn genotypes on the basis of their PE. Three generations (F1, F2, and F2:3) were developed in three planting seasons by manual cross-pollination and self-pollination. A total of 376 ears from the F2:3 generation were selected, shelled, and subjected to phenotypic analysis. Genetic variability was observed in the F2 and F2:3 generations, and their average PE value was 31.5 ± 6.7 mL g−1. PE prediction models using partial least square (PLS) regression were developed, and the root mean square error of calibration (RMSEC) was 6.08 mL g−1, while the coefficient of determination (RC2) was 0.26. The model developed by principal component analysis with quadratic discriminant analysis (PCA-QDA) was the best for discriminating the kernels with low PE (≤30 mL g−1) from those with high PE (>30 mL g−1) with an accuracy of 78%, sensitivity of 81.2%, and specificity of 72.2%. Although NIR spectroscopy appears to be a promising non-destructive method for assessing the PE of intact popcorn kernels for narrow breeding populations, greater variability and larger sample sizes would help improve the robustness of the predictive and classificatory models.

Quality Protein Popcorn (QPP) BC2F5 inbred lines were produced through an interpopulation breeding system between Quality Protein Maize dent (QPM) and elite popcorn germplasm. In 2019, five QPP F1 hybrids were selected for further evaluation due to superior agronomics, endosperm protein quality, and popping quality traits. Though these BC2F5 QPP hybrids were phenotypically similar to their popcorn parents, the QPP cultivars conveyed slightly inferior popping characteristics when compared to the original popcorn germplasm. The objective of this study was twofold. First, BC2F5 inbred lines were crossed to their popcorn parents and BC3F4 inbred lines were produced for hybridization to test the agronomic, protein, and popping trait effects from an additional QPP by popcorn backcross. Second, BC2- and BC3-hybrids were simultaneously evaluated alongside ConAgra Brands® elite cultivars and ranked for potential commercialization in the spring of 2020. These 10 QPP hybrids were grown alongside five ConAgra Brands® elite popcorn cultivars in three locations and agronomic, protein quality, and popping quality traits were evaluated. Significant improvements in popcorn quality traits were observed in the QPP BC3 cultivars compared to their BC2 counterparts, and yield averages were significantly lower in BC3-derived QPP hybrids compared to the BC2 population. Protein quality traits were not significantly different between QPP backcrossing populations and significantly superior to ConAgra elite popcorn varieties. Utilizing a previously published ranking system, six QPP hybrids, three from the BC2F5 population and three from the BC3F4 population, were evaluated as candidates for final selection. The successful evaluation and ranking system methodology employed is transferable to other hybrid production and testing programs. Incorporating this analysis with concurrent sensory studies, two QPP hybrids were chosen as premier cultivars for potential commercialization.

… Therefore, there is an enormous need for lines from heterotic groups adapted to different envi… The objective of the present study was to evaluate the combining ability of 10 popcorn lines …