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Fruit architecture and morphology-related traits are among the determinants of fruit diversity and are major contributors to yield and yield potential in chile pepper (Capsicum spp.). This study aimed to characterize 105 genotypes of a Capsicum diversity panel consisting of cultivars, breeding lines, landrace, and wild species belonging to twelve different pod (fruit) types, for 32 morphometric Tomato Analyzer (TA) descriptors. Hierarchical cluster analysis grouped the genotypes into eight clusters based on the TA descriptors. A multivariate principal component analysis yielded two principal components, PC1 and PC2, which explained 53.24% and 10.11% of the variation in fruit diversity, respectively. The basic measurements—namely, perimeter, area, width midheight, maximum width, height midwidth, maximum height, and curved height were the most discriminating descriptors with a maximum contribution to the overall fruit shape. There was a strong, positive correlation for basic measurements and fruit shape index, whereas blockiness was negatively correlated with distal angle macro. Additive genetic effects and high heritability for the fruit traits were observed. Results of this study will provide valuable information to breed high-yielding chile pepper cultivars based on fruit morphology traits.

Characterization of local germplasm is an effective way to identify elite breeding material and develop improved varieties. This study was aimed to assess 52 tomato accessions comprised of local varieties (28), landraces (8), breeding lines (14), and wild relatives (2), and their characterization for 30 morphological/agronomic, four fruit quality, and tomato mosaic virus (ToMV) resistance traits. Morphological, quality, and ToMV traits were evaluated using phenotyping, biochemical assays, and molecular markers, respectively. Fruit shape and size showed appreciable variation, with fruits varying from rounded to heart shaped and small to big size. Significant variation was observed for fruit weight (1.6–564.8 g), fruits per plant (6.0–174.7), productivity (130.5–5146.5 g), soluble solids (4.1%–8.4%), vitamin C (9.5–46.4 mg·100 g−1), antioxidant activity (2.5–9.6 μmol Fe2+·g−1 fresh weight), and total polyphenols (23.9–124.2 GAE·100 g−1 fresh weight). All accessions were phenotypically screened for the virus resistance in the growth chamber, and CAPS molecular markers were used to identify accessions with ToMV Tm-22 resistant alleles, and accessions LYC-13, LYC-15, LYC-17, LYC-26, and LYC-52 were identified as resistant. Multivariate analysis of morphological and quality traits showed that 35 principal components contributed to the total variation and the first two and 12 principal components explained 47.2% and 90% of the variation, respectively. The evaluated tomato collection appears to have breeding potential, and around 20% of the accessions in the collection (LYC-6, LYC-17, LYC-18, LYC-26 to LYC-31, and LYC 33) are promising genetic resources for variety development that are enriched with enhanced fruit quality and high yield.

Selection of high-performance lines with respect to traits of interest is a key step in plant breeding. Genomic prediction allows to determine the genomic estimated breeding values of unseen lines for trait of interest using genetic markers, e.g. single-nucleotide polymorphisms (SNPs), and machine learning approaches, which can therefore shorten breeding cycles, referring to genomic selection (GS). Here, we applied GS approaches in two populations of Solanaceous crops, i.e. tomato and pepper, to predict morphometric and colorimetric traits. The traits were measured by using scoring-based conventional descriptors (CDs) as well as by Tomato Analyzer (TA) tool using the longitudinally and latitudinally cut fruit images. The GS performance was assessed in cross-validations of classification-based and regression-based machine learning models for CD and TA traits, respectively. The results showed the usage of TA traits and tag SNPs provide a powerful combination to predict morphology and color-related traits of Solanaceous fruits. The highest predictability of 0.89 was achieved for fruit width in pepper, with an average predictability of 0.69 over all traits. The multi-trait GS models are of slightly better predictability than single-trait models for some colorimetric traits in pepper. While model validation performs poorly on wild tomato accessions, the usage as many as one accession per wild species in the training set can increase the transferability of models to unseen populations for some traits (e.g. fruit shape for which predictability in unseen scenario increased from zero to 0.6). Overall, GS approaches can assist the selection of high-performance Solanaceous fruits in crop breeding.

In dryland regions, soil moisture stress often leads to desiccation and causes injury to photosynthetic machinery. Recently, chlorophyll fluorescence (ChlF)-based assessment of photosynthetic efficiency under drought stress is gaining attention due to advances in instrument development and methodology optimisation. Our study was designed to explore the use of spike photosynthetic efficiency as a trait to differentiate drought responses in wheat. Bread and durum wheat were assessed for spike, stem, and leaf tissue photosynthetic efficiency in response to progressive desiccation using ChlF imaging. Results showed that durum wheat had higher quantum efficiency and lower photoinhibition of PSII relative to bread wheat across spike, stem, and leaf. Rate of decline in maximum photochemical efficiency of PSII with increased desiccation was seen higher in bread wheat spikes as compared to durum wheat. Our investigation clearly demonstrated that ChlF imaging could be effectively deployed as phenotyping tool to differentiate wheat genotypes for their photosynthetic performance under desiccation.

The Balkan pepper breeding program aims to use in vitro embryogenesis (anther culture) to develop doubled haploid pepper lines with valuable traits. We analyzed the effectiveness of microspore embryogenesis on 17 pepper genotypes comprised of varieties, breeding lines, and F1 hybrids of different varietal types (conical, bell shape, and kapia) and characterized the agronomic traits of newly generated doubled haploid lines. The highest androgenic potential was observed in the variety Stryama and breeding line 560/06 with 9.55 and 13.00% reacted anthers, respectively. Of the 186 regenerated plants, 147 were successfully adapted with a survival index of 79.03%. Flow cytometry analysis showed that the haploid:diploid ratio of regenerants was 1.5:1. All diploid plants were confirmed to be androgenic in origin. There were significant differences in terms of quantitative fruit characteristics of length, width, weight, pericarp weight, pericarp thickness, and productivity per plant among the diploid lines. Also, androgenic lines 21, 23, and 74 derived from Stryama and line 55 obtained from Zlaten medal 7 were distinguished with higher values of some fruit traits compared to initial genotypes. Additionally, several androgenesis lines (Stryama lines 21, 23, and 74, and Zlaten medal 7 line 55) scored higher for some fruit traits compared to the initial genotype. These results show that anther culture is a promising tool for the creation of Balkan pepper breeding lines with improved traits.

Maize has played a key role in the sustenance and cultural traditions of the inhabitants of the southwestern USA for many centuries. Blue maize is an important component of the diverse landraces still cultivated in the region but the degree to which they are related is unknown. This research was designed to ascertain the genotypic, morphological, and phenotypic diversity of six representative southwestern blue maize landraces. Their genotypic diversity was examined using tunable genotyping-by-sequencing (tGBS™). A total of 81,038 high quality SNPs were identified and obtained through tGBS. A total of 45 morphological and biochemical traits were evaluated at two locations in New Mexico. The varieties Los Lunas High and Flor del Rio were genetically less related with other southwestern landraces whereas diffusion between Navajo Blue, Hopi Blue, Yoeme Blue, and Taos Blue demonstrated that these landraces were genetically related. Phenotypic variability was highest for kernel traits and least for plant traits. Plant, ear, and kernel traits were fairly consistent within and across locations. Principal component analysis and tGBS showed that Corn Belt variety ‘Ohio Blue’ was distinctly different from southwestern landraces. Genotypic analysis displayed that southwestern landraces are genetically closely related, but selection has resulted in differing phenotypes. This study has provided additional insight into the genetic relatedness of southwestern blue maize landraces.

Region-specific local landraces represent a germplasm diversity adapted and acclimatized to local conditions, and are ideal to breed for targeted market niches while maintaining the variability of heirloom traits. A collection of 180 pepper accessions, collected from 62 diverse locations across six Balkan countries, were characterized and evaluated for phenotypic and biochemical variation during a multi-year environment. An assortment of 32 agro-morphological, fruit quality, and virus resistance traits were evaluated, and the top 10% accessions were identified. A wide range of trait variation concerning plant architecture, inflorescence and fruit traits, yield and fruit quality was observed, and appreciable variation was noticed. According to hierarchical clustering, six distinct clusters were established based on pre-defined varietal groups. Divergence among accessions for phenotypic and fruit compositional variability was analyzed, and eight principal components were identified that contributed ~71% of the variation, with fruit shape, width, wall thickness, weight, and fruit quality traits being the most discriminant. Evaluation of the response to tobacco mosaic virus (TMV) and pepper mild mottle mosaic virus (PMMoV) showed that 24 and 1 accession were resistant, respectively while no tomato spotted wilt virus (TSWV) resistance was found. Considerable diversity for agro-bio-morphological traits indicates the Balkan pepper collection as good gene sources for pre-breeding and cultivar development that are locally adapted.

Anther or microspore culture induced haploid and double haploids (DH) are increasingly being utilized by breeders since it can shorten breeding time by achieving complete homozygosity within a single generation. Pepper (Capsicum annuum L.) is one of the most important vegetables, distinguished by its high level of heterozygosity, making the breeding process very laborious and long. Fourteen different DH lines were obtained as a result of anther culture of four parental genotypes. Data from different plant and fruit morphological traits as well as quality traits including vitamin C, dry matter content, total polyphenols and antioxidant activity were collected. A total of 47 different descriptors for fruit morphology and color were characterized using Tomato Analyzer v. 3 software. Findings from this research revealed significant variation of fruit morphology, quality and productivity traits between DH lines and their respective parental genotypes. Among these studied 14 DH lines, 42.9% were superior to the parental genotypes for fruit weight, width, fruit wall thickness, and usable part of the fruits. As compared to parental genotypes, DH lines exhibited higher values for tested fruit quality traits and dry matter content. Multivariate analysis allowed us to identify the trait combination that contributed to the total variation. A total of eight principle components (PCs) explained 95.4% variation with PC1 and PC2 contributing 32.4% and 21.1%, respectively. Pepper androgenesis clearly indicates its usefulness as a well established technique that can allow pepper breeders to save the time and breeding resources by expediting the breeding process. Our research findings prove the advantages of pepper androgenesis to utilize the diversity of pepper genetic resources and development of novel pepper breeding lines to utilize in future breeding.

One aim of this experiment was to develop NIR calibrations for 20-grain components in 143 pigmented maize samples evaluated in four locations across New Mexico during 2013 and 2014. Based on reference analysis, prediction models were developed using principal component regression (PCR) and partial least squares (PLS). The predictive ability of calibrations was generally low, with the calibrations for methionine and glycine performing best by PCR and PLS. The second aim was to explore the relationships among grain constituents. In PCA, the first three PCs explained 49.62, 22.20, and 6.92% of the total variance and tend to align with nitrogen-containing compounds (amino acids), carbon-rich compounds (starch, anthocyanin, fiber, and fat), and sulfur-containing compounds (cysteine and methionine), respectively. Correlations among traits were identified, and these relationships were illustrated by a correlation network. Some relationships among components were driven by common synthetic origins, for example, among amino acids derived from pyruvate. Similarly, anthocyanins, crude fat, and fatty acids all share malonyl CoA in their biosynthetic pathways and were correlated. In contrast, crude fiber and starch have similar biosynthetic origins but were negatively correlated, and this may have been due to their different functional roles in structure and energy storage, respectively.

For years, the main emphasis of industrial pepper production has been the creation of large-fruited high-yielding varieties. This has led to the exploitation of pepper (Capsicum annuum L.) varieties with a significantly narrow genetic background. The Balkan region has a range of valuable local landraces that are noticeably decreasing in prevalence and may be lost. In this study, we utilized Tomato Analyzer (TA) to characterize the intra- and inter-varietal type fruit diversity using 50 different fruit shape, size, and color descriptors of a Balkan pepper collection. The collection comprised of 168 diverse accessions and collected from 62 locations and 31 districts in six different Balkan countries. Fruit shape was the main trait used for visual accession grouping into 5 different varietal groupings of elongated, round, conical, bell, and pumpkin shape, respectively. Beyond visual grouping, hierarchical cluster analysis grouped the evaluated accessions into eight distinct clusters based on fruit shape, size, surface, and color. In total, 47 TA descriptors were identified to contribute to the total variation, with first two components explaining 54% of variation, and 90% of variation contained in 12 components. Among TA descriptors, fruit size and proximal/distal fruit end shape contributed to component 1 variation whereas fruit perimeter, area and color contributed to component 2. We hope that this research will assist pepper breeding and genetic resources communities to better understand Balkan pepper fruit diversity and develop pepper varieties with desirable fruit traits. Quantification of fruit diversity could be crucial for further investigation into the genetic determinants of fruit shape and size by a genome-wide association study.

BACKGROUND Anthocyanin-rich blue corn is an emerging specialty crop in the USA. The antioxidant properties of blue corn offer health benefits in the human diet. The objectives of this study were to identify, characterize and quantify the anthocyanins from blue corn. Hypotheses tested were that total anthocyanin content was similar among southwestern US accessions and that it would vary across locations. It was also examined whether different anthocyanin components were unique to certain genotypes. RESULTS Across all locations and accessions, an average of 0.43 g kg−1 total anthocyanin content (TAC) was observed. Accessions Santa Clara Blue and Ohio Blue displayed the highest TAC. The TAC of accession Flor del Rio was lower by nearly a factor of six. A total of five anthocyanin components were identified. Cyanidin 3-glucoside was the most abundant, followed by pelargonidin and peonidin 3-glucoside. Succinyl and disuccinyl glycosidic forms of cyanidin were also identified. Cyanidin 3-disuccinylglucoside was newly identified as a novel form of anthocyanin. CONCLUSION Quantitative and qualitative anthocyanin expression was determined to be relatively stable across multiple southwestern environments. Increased expression of red and purple pigmentation in accession Flor del Rio appeared to be associated more with reduced TAC and cyanidin 3-glucoside than with elevated pelargonidin per se. A previously unreported anthocyanin component in blue corn, cyanidin 3-disuccinylglucoside, is present in southwestern landraces. © 2016 Society of Chemical Industry

Recurrent surge in demand of multipurpose peppers have positively encouraged pepper breeding community to study diverse aspects of pepper genetics, physiology, breeding and biotic stresses, however research on application of anther culture in pepper is still limited. Current study was aimed to assess the in vitro androgenic response of two prominent Bulgarian pepper varieties in five different duration times (12, 14, 16, 18 and 20 days) on incubation period and regeneration mediums containing kinetin (0.1, 0.2 and 0.3 mg L-1) and combination of zeatin (0.25 mg L-1 0.5 mg L-1) and indole acetic acid (IAA) (0.1 mg L1). Experimental results indicated specific requirements for composition of culture medium and duration time depending on genotype. Prolonged anthers incubation on induction medium had a positive effect on embryo formation and their conversion into plantlets compared to regeneration medium variants. Highest number of embryos and plant-regenerants of variety Stryama was achieved after 18 days incubation period and medium variant containing 0.1 mg L-1 kinetin. Embryo induction in variety Zlaten Medal 7 was higher after 16 days and control medium without plant growth regulators, while regeneration at 20 days also on control medium variant.

Recurrent surge in demand of multipurpose peppers have positively encouraged pepper breeding community to study diverse aspects of pepper genetics, physiology, breeding and biotic stresses, however research on application of anther culture in pepper is still limited. Current study was aimed to assess the in vitro androgenic response of two prominent Bulgarian pepper varieties in five different duration times (12, 14, 16, 18 and 20 days) on incubation period and regeneration mediums containing kinetin (0.1, 0.2 and 0.3 mg L-1) and combination of zeatin (0.25 mg L-1 0.5 mg L-1) and indole acetic acid (IAA) (0.1 mg L1). Experimental results indicated specific requirements for composition of culture medium and duration time depending on genotype. Prolonged anthers incubation on induction medium had a positive effect on embryo formation and their conversion into plantlets compared to regeneration medium variants. Highest number of embryos and plant-regenerants of variety Stryama was achieved after 18 days incubation period and medium variant containing 0.1 mg L-1 kinetin. Embryo induction in variety Zlaten Medal 7 was higher after 16 days and control medium without plant growth regulators, while regeneration at 20 days also on control medium variant.

Tomato spotted wilt virus (TSWV) is one of the most destruc-tive pathogens worldwide. In Bulgaria the virus was found toseverely damage a number of solanaceous vegetables andca.25 ornamentals (Hristova et al.2001 ). In spring 2014, about30% of lisianthus plants (ca. 1000 plants) grown in a privatefarm nearby Plovdiv, Bulgaria showed yellowing and/or lightbrown necrosis on leaves and petals followed by subsequentwilting. To identify the causal agent of this infection,Chenopodium quinoa,Nicotiana glutinosa,andPetuniahybridaplants were sap inoculated with material from 10symptomatic individuals.