Common Bean Genotypes Research Articles

A mass spectrometry-based peptidomic dataset of the spermosphere in common bean (Phaseolus vulgaris L.) seeds

The spermosphere, a dynamic microenvironment surrounding germinating seeds, is shaped by the complex interactions between natural compounds exuded by seeds and seed-associated microbial communities. While peptides exuded by plants are known to influence microbiota diversity, little is known about those specifically exuded by seeds. In this study, we characterised the peptidome profile of the spermosphere for the first time using seeds from eight genotypes of common bean (Phaseolus vulgaris) grown in two contrasting production regions. An untargeted LC-MS/MS peptidomic analysis revealed 3,258 peptides derived from 414 precursor proteins of common bean in the spermosphere. This comprehensive peptidomic dataset provides valuable insights into the characteristics of peptides exuded by common bean seeds in the spermosphere. It can be used to identify peptides with potential antimicrobial or other biological activities, advancing our understanding of the functional roles of seed-exuded peptides in the spermosphere.

Northwestern Himalayan common beans: A Treasure Trove for breeding resistant bean cultivars for multiple foliar pathogens

Common bean (Phaseolus vulgaris. L) is attacked by a lot of important foliar diseases like anthracnose, Bean Common Mosaic Virus, angular leaf spot, Bean Golden Yellow Mosaic Virus, and common bacterial blight. In the present study, we exploited anthracnose resistant germplasm of 122 common bean genotypes for the identification of broad spectrum and durable resistance for multiple foliar diseases. We utilized linked molecular markers and found some promising genotypes with 11 resistance genes. These genotypes possess significant potential as parental lines for gene pyramiding strategies, to enhance disease resistance in common beans. We also highlighted the need for new generation markers over SCAR markers to streamline genotypic screening and expedite the breeding of disease-resistant common bean varieties. Our phenotypic studies identified a few bean landraces highly resistant to the new BCMV NL-1n strain. Consequently, the genome wide association study also confirms the presence of already identified resistance genes. Additionally, our study reconfirms the presence of the recently identified bc-urgene in our material. The bean landraces of northern India contain novel regions associated with BCMV resistance on Pv03, Pv05, Pv04, Pv06, Pv07, Pv09, and Pv11. This study provides the list of bean genotypes that can be used to breed resistant cultivars and may also contain new resistance genes to a most important viral disease of common beans.

Morpho–Molecular Characterization of Brazilian Common Bean Landraces Varieties and Commercial Cultivars

This study aimed to characterize forty genotypes (31 landrace varieties and nine commercial cultivars) of common bean (Phaseolus vulgaris L.) morphologically and molecularly. Morphological descriptors were evaluated during seedling, flowering, physiological maturation and post-harvest stages. Ten microsatellite markers were used for molecular screening. The markers were analyzed according to the number of alleles per locus, the allele frequency per locus and the polymorphism in content (PIC). Genetic distances and cluster analysis were performed using Bayesian inference and the UPGMA method. All black beans evaluated have anthocyanin in the cotyledons, hypocotyls and stems, and their flowers are purple. For the growth habit, 50% of the evaluated genotypes belong to type III, and at the physiological maturation stage, yellow color is predominant in the pods (85%). Through the genetic dissimilarity, three groups were observed for the likelihood reason, and five groups were observed through the UPGMA method, a strong indication of the wide genetic diversity among the evaluated genotypes. All genotypes from the Andean center of origin were grouped into the same cluster.

DTALE approach demonstrates that induction of common bean OVATE Family Protein 7 (PvOFP7) promotes resistance to common bacterial blight

Abstract Common bacterial blight of bean (CBB) is a devastating seed-transmitted disease caused by Xanthomonas phaseoli pv. phaseoli and Xanthomonas citri pv. fuscans on common bean (Phaseolus vulgaris L.). The genes responsible for CBB resistance are largely unknown. Moreover, the lack of a reproducible and universal transformation protocol limits the study of genetic traits in common bean. We produced X. phaseoli pv. phaseoli strains expressing artificially-designed Transcription-Activator Like Effectors (dTALEs) to target 14 candidate genes for resistance to CBB based on previous transcriptomic data. In planta assays in a susceptible common bean genotype showed that induction of PvOFP7, PvAP2-ERF71 or PvExpansinA17 expression by dTALEs resulted in CBB symptom reduction. After PvOFP7 induction, in planta bacterial growth was reduced at early colonisation stages and RNA-Seq analysis revealed up-regulation of cell wall formation and primary metabolism, together with major down-regulation of Heat Shock Proteins. Our results demonstrate that PvOFP7 contributes to CBB resistance, and underline the usefulness of dTALEs for functional validation of genes whose induction impacts Xanthomonas-plant interaction.

Cooking Time, Seed Darkening, and Iron and Zinc Concentrations of Selected Andean Genotypes of Common Bean

ABSTRACTCooking time (CT), post‐harvest darkening (PHD), and micronutrient content influence consumer preference of common bean (Phaseolus vulgaris L.) varieties. The objective of this study was to evaluate Andean genotypes for CT, PHD, and seed iron and zinc concentration. A total of 52 genotypes belonging to three market classes, namely, purple‐speckled (Kabulangeti), yellows, and cranberry (sugar beans), were grown at the Golden Valley Agricultural Research Trust (GART) Farm and the Mpika Research Farm in Zambia and assessed for CT, PHD, and seed iron and zinc concentration. The fastest cooking genotype among all 52 genotypes was a yellow genotype, Y1612‐5. Yellow genotypes generally cooked faster than the Kabulangeti and sugar types. Among the elite lines with Kabulangeti seed types, which is a dominant market class in Zambia, the elite line K175 had faster CT and higher iron and zinc concentration than the Kabulangeti landrace race currently available on the Zambian market. Kabulangeti and sugar genotypes showed regular darkening, whereas yellows did not darken. The yellow genotype Y1612‐3 was particularly outstanding because of its unique combination of high concentrations of both iron and zinc. Therefore, it can be used to introgress these two essential minerals into variable genetic backgrounds. The significant variability and high to moderate heritability for CT (0.85) and iron (0.81) and zinc (0.58) concentration observed in the current study suggest that it is possible to make progress in breeding for faster cooking varieties that are rich in iron and zinc.

Variation in Grain Mineral Concentrations of 63 Common Bean Genotypes Planted at Malkerns, Eswatini, in Africa

ABSTRACTLow soil mineral concentrations are a major limitation to the nutritional quality of grain crops produced in Africa. As a result, 232 million people are suffering from microelement deficiency and 239 million from protein‐calorie malnutrition in Africa. This study evaluated the nutritional quality of common bean grain harvested from 63 genotypes planted at Malkerns in Eswatini. The results showed significantly marked differences in the concentrations of 10 dietarily important nutrient elements. Of the macronutrients, Na levels showed the highest variation (12.00–91.00 mg/g) among the 63 bean genotypes, followed by K (14.03–22.03 mg/g) and P (3.30–9.57 mg/g), with Mg (1.57–2.30 mg/g) and Ca (0.80–2.68 mg/g) concentrations exhibiting the least difference among the bean genotypes. Of the micronutrients, Fe levels revealed the highest variation (66.36–151.08 mg/kg), followed by Zn (23.57–70.72 mg/kg) and Mn (11.53–26.84 mg/kg), with B (10.06–17.65 mg/kg) and Cu (6.30–13.67 mg/kg) exhibiting relatively lower differences among the 63 common bean genotypes. However, genotype NUC 461 recorded the highest grain concentrations of P, K, Mg, Fe, Cu, Zn, and B, followed by DAB 155, which also revealed high levels of P, K, Ca, Fe, Zn, and Mn in its seeds. For improved human health and nutrition, the two bean genotypes would be the ideal candidates to recommend to commercial bean growers and resource‐poor farmers. However, the mechanisms underlying the greater accumulation of six to seven dietarily important nutrient elements by genotypes NUC 461 and DAB 155 remain to be determined.

Agronomic and morpho‐physiological response of Andean genotypes of common bean to terminal drought

AbstractDrought is a major production constraint of common bean (Phaseolus vulgaris L.) worldwide. The objectives of this study were to (i) assess the agronomic and morpho‐physiological response of Andean genotypes to terminal drought, and (ii) identify Andean genotypes with an ideal combination of agronomic and morpho‐physiological traits for enhanced drought tolerance. Twenty Andean genotypes and seven checks were evaluated for drought tolerance in three field trials conducted in three locations. Agronomic and morpho‐physiological traits including seed yield, seed weight, shoot dry weight, pod number, pod harvest index, harvest index, and carbon isotope discrimination (CID) were measured. Strong positive correlations were observed between seed yield, and partitioning efficiency metrics and CID (r = 0.57***) under drought, which suggested the important role of assimilate partitioning and water use efficiency in the observed drought tolerance. The heritability estimates for pod harvest index (H2 = 0.88) and harvest index (H2 = 0.87) were higher than for seed yield (H2 = 0.43) and other morpho‐physiological traits, thus they can be used to indirectly select for drought tolerance. Based on the relationship between seed yield and CID under drought stress, 12 genotypes were identified as drought tolerant with high water use efficiency. Among these, three were classified as water savers, while nine as water spenders. Genotypes with an ideal combination of superior shoot dry weight, partition efficiency, water use efficiency, and superior seed yield under both drought stress and non‐stress conditions were identified. The identified genotypes can be used for genetic improvement of drought tolerance in the Andean gene pool of common bean.

Adaptation, Path Coefficient and Correlation Study of Yield and Associated Traits in Common Bean (Phaseolus vulgaris L.) Genotypes

The study evaluated new biofortified, high-yielding and disease-resistant bean varieties for their adaptability in Zimbabwe. The secondary objective was to assess the association between yield and other traits that contribute to grain yield and identify traits that have direct and indirect effects on grain yield. The study was conducted between December 2016 and June 2017 using an augmented design with 24 varieties replicated three times at Chinhoyi University of Technology Research Farm. Data was analysed using analysis of variance in the statistical analysis system (SAS) software. DAB482, DAB494 and DAB539 were identified as high-yielding varieties with desired disease tolerance to common bean blight (CBB), common leaf rust (CLR) and angular leaf spot). Therefore, these improved common bean varieties recommended for further multilocation evaluation with the potential to be released as commercial varieties. Correlation coefficient values and path analysis values (direct and indirect) showed that the weight of 100 randomly selected seeds per variety and the percentage number of plants that germinated per plot could be used for indirect selection for grain yield (kg/ha). A negative correlation indicates an inverse relationship between traits. This study observed significant negative correlations for CBB and CLR relative to grain yield (kg/ha). This suggests that the grain yield (kg/ha) decreases with increased disease incidence and severity, highlighting the importance of disease tolerance in achieving high grain yield. Hence, there is a need for the breeding program to select and advance varieties that are tolerant to diseases to achieve the desired improvement in grain yield performances.

Genetic Diversity of Common Bean (Phaseolus vulgaris L.) Landraces Based on Morphological Traits and Molecular Markers.

The objective of this study was to evaluate the genetic diversity among traditional common bean accessions through morphological descriptors and molecular markers. Sixty-seven common bean accessions from the Germplasm bank of the Instituto Federal of Espírito Santo-Campus de Alegre were evaluated. For this, 25 specific morphological descriptors were used, namely 12 quantitative and 13 qualitative ones. A diversity analysis based on morphological descriptors was carried out using the Gower algorithm. For molecular characterization, 23 ISSR primers were used to estimate dissimilarity using the Jaccard Index. Based on the dendrograms obtained by the UPGMA method, for morphological and molecular characterization, high genetic variability was observed between the common bean genotypes studied, evidenced by cophenetic correlation values in the order of 0.99, indicating an accurate representation of the dissimilarity matrix by the UPGMA clustering. In the morphological characterization, high phenotypic diversity was observed between the accessions, with grains of different shapes, colors, and sizes, and the accessions were grouped into nine distinct groups. Molecular characterization was efficient in separating the genotypes in the Andean and Mesoamerican groups, with the 23 ISSR primers studied generating an average of 6.35 polymorphic bands. The work identified divergent accessions that can serve different market niches, which can be indicated as parents to form breeding programs in order to obtain progenies with high genetic variability.

Use of Bayesian probabilistic model approach in common bean varietal recommendation

AbstractRecommendation of new varieties is supported by value for cultivation and use (Valor de Cultivo e Uso [VCU]) trials. For a more reliable recommendation, it is necessary to identify methodologies that make better use of the genotype‐by‐environment interaction (GEI). The methodology proposed by Dias et al. is an alternative to take advantage of the GEI; it considers concepts of Bayesian models and probability methods of adaptation and stability analysis in a single model, classifying the genotypes regarding possible success based on a defined selection intensity. Thus, the aim of the present study was to explore the use of Bayesian probabilistic method for the purpose of recommend common bean (Phaseolus vulgaris L.) varieties. To that end, we used grain yield data from 15 genotypes of common bean evaluated in 42 environments distributed over different crop seasons, years, and locations in regard to VCU trials conducted from 2016 to 2018. Under a predefined selection intensity of 30%, the genotypes with greater marginal probability of superior performance were G01, G14, G07, G11, and G02. The genotypes with greater marginal probability of superior stability were G06, G07, G04, G03, and G12. Considering the joint probability of superior performance and yield stability, the genotypes G07, G14, G01, G11, and G04 stand out. Therefore, the use of the Bayesian probabilistic method showed promise in recommendation of common bean varieties.

Diversity in stomatal and hydraulic responses to post-flowering drought in common (Phaseolus vulgaris) and tepary (P. acutifolius) beans.

Plants differ widely in how soil drying affects stomatal conductance (gs) and leaf water potential (ψleaf), and in the underlying physiological controls. Efforts to breed crops for drought resilience would benefit from a better understanding of these mechanisms and their diversity. We grew 12 diverse genotypes of common bean (Phaseolus vulgaris L.) and four of tepary bean (P. acutifolius; a highly drought resilient species) in the field under irrigation and post-flowering drought, and quantified responses of gs and ψleaf, and their controls (soil water potential [ψsoil], evaporative demand [Δw] and plant hydraulic conductance [K]). We hypothesised that (i) common beans would be more "isohydric" (i.e., exhibit strong stomatal closure in drought, minimising ψleaf decline) than tepary beans, and that genotypes with larger ψleaf decline (more "anisohydric") would exhibit (ii) smaller increases in Δw, due to less suppression of evaporative cooling by stomatal closure and hence less canopy warming, but (iii) larger K declines due to ψleaf decline. Contrary to our hypotheses, we found that half of the common bean genotypes were similarly anisohydric to most tepary beans; canopy temperature was cooler in isohydric genotypes leading to smaller increases in Δw in drought; and that stomatal closure and K decline were similar in isohydric and anisohydric genotypes. gs and ψleaf were virtually insensitive to drought in one tepary genotype (G40068). Our results highlight the potential importance of non-stomatal mechanisms for leaf cooling, and the variability in drought resilience traits among closely related crop legumes.

Contrasting Dynamic Photoprotective Mechanisms under Fluctuating Light Environments between an Andean and a Mesoamerican Genotype of Phaseolus vulgaris L.

Plants have evolved various photosynthetic adaptations and photoprotective mechanisms to survive in fluctuating and extreme light environments. Many light-activated photosynthetic proteins and enzymes adjust to plant leaf anatomy and leaf pigments to facilitate these processes. Under excessive amounts of light, plants use non-photochemical quenching (NPQ) mechanisms to dissipate excess absorbed light energy as heat to prevent photoinhibition and, therefore, mitigate damage to the plant’s photosystems. In this study, we examined photosynthetic adaptations to the light environment in common beans using representative genotypes of the Andean (Calima) and the Mesoamerican (Jamapa) gene pools. We estimated their leaf chlorophyll fluorescence characteristics using dark- and light-adapted mature leaves from three-week-old plants. Our results indicated a higher chlorophyll fluorescence of the light-adapted leaves in the Mesoamerican genotype. NPQ induction was early and extended in the Andean genotype. A similar response in the Mesoamerican counterpart required high light intensity (≥1500 PAR). The NPQ relaxation was rapid in the Mesoamerican genotype (t1/2: 6.76 min) but sluggish in the Andean genotype (t1/2: 9.17 min). These results indicated variable adaptation to light environments between the two common bean genotypes and suggested different strategies for surviving fluctuating light environments that can be exploited for developing plants with environmentally efficient photosynthesis under light limitations.

Phosphorus use efficiency in common bean genotypes

Phosphorus absorption in plants can vary depending on the genotypes, mineral levels, and environmental conditions. Thus, this study aimed to evaluate phosphorus use efficiency and the response capacity of five common bean genotypes in two cultivation cycles. A 2x5 factorial scheme was used with three replicates. Factor A consisted of using and not phosphorus fertilization, and factor B consisted of five common bean genotypes (BRS Expedito, Iraí, Pérola, Maronze, and Vermelho). The evaluated yield components were the number of pods per plant (NPP), the number of grains per plant (NGP), and the mass of 1000 grains (M1000G). The yield was calculated and extrapolated to kg ha-1. We also evaluated the phosphorus levels accumulated in the leaves and grains (mg and %) and estimated the use efficiency of using phosphorus in the grains. The data obtained were subjected to analysis of variance and compared using the Scott-Knott test at a 5% significance level. There was a significant interaction for all studied variables, indicating the interference of phosphorus fertilization in the behavior of the genotypes. The growing season influenced the genotypes' responses regarding phosphorus use. Yields increased with phosphorus fertilization and changed according to genotype. The phosphorus accumulated in the leaves and grains showed little divergence. The Iraí, Pérola, and Maronze genotypes stand out for their efficient use of phosphorus, presenting an increase above 50% when grown in soil with phosphorus fertilization. When fertilized, the Vermelho variety most accumulated phosphorus in the grains in the first season. In the second season, it showed a significant change in its response when using the phosphate fertilizer, indicating a change in behavior due to the environmental component.

Comparative Effects of Water Scarcity on the Growth and Development of Two Common Bean (Phaseolus vulgaris L.) Genotypes with Different Geographic Origin (Mesoamerica/Andean).

Drought stress is widely recognized as a highly detrimental abiotic stress factor that significantly impacts crop growth, development, and agricultural productivity. In response to external stimuli, plants activate various mechanisms to enhance their resistance or tolerance to abiotic stress. The common bean, a most important legume according to the FAO, serves as a staple food for millions of people worldwide, due to its rich protein, carbohydrate, and fiber content, concurrently, and water scarcity is the main factor limiting common bean production. The process of domestication and on-farm conservation has facilitated the development of genotypes with varying degrees of drought stress resistance. Consequently, using landraces as biological material in research can lead to the identification of variants with superior resistance qualities to abiotic stress factors, which can be effectively integrated into breeding programs. The central scope of this research was to find out if different geographic origins of common bean genotypes can determine distinct responses at various levels. Hence, several analyses were carried out to investigate responses to water scarcity in three common bean genotypes, M-2087 (from the Mesoamerican gene pool), A-1988 (from the Andean gene pool) and Lechinta, known for its high drought stress resistance. Plants were subjected to different water regimes, followed by optical assessment of the anatomical structure of the hypocotyl and epicotyl in each group; furthermore, the morphological, physiological, and biochemical parameters and molecular data (quantification of the relative expression of the thirteen genes) were assessed. The three experimental variants displayed distinct responses when subjected to 12 days of water stress. In general, the Lechinta genotype demonstrated the highest adaptability and drought resistance. The M-2087 landrace, originating from the Mesoamerican geographic basin, showed a lower resistance to water stress, compared to the A-1988 landrace, from the Andean basin. The achieved results can be used to scale up future research about the drought resistance of plants, analyzing more common bean landraces with distinct geographic origins (Mesoamerican/Andean), which can then be used in breeding programs.

Revealing the Nexus between Fertilizer Composition and the Performance of Common Bean (Phaseolus vulgaris L.) Genotypes in the Himalayan Heartland of India

Gaining insight into the interplay between crucial fertilizers and their impact on crop characteristics is crucial for enhancing the agricultural output and promoting sustainable crop administration. The objective of this study was to assess the growth, productivity, and nutrient-use efficiency (NUE) of common bean genotypes with varying levels of NPK. In the RCBD field study, three genotypes of common bean were cultivated—SKUA-WB-5000/1446 (V1), SKUA-WB-5002/185 (V2), and SKUA-WB-5003/1492 (V3)—together with six combinations of NPK (N2:P2O5:K2O kg ha−1). The findings indicated that the height of the plants had a positive correlation with elevated NPK levels subsequent to the maximum point in NPK 10-20-10. The V1 genotype exhibited superior growth and productive traits, particularly with regard to its higher seed index and much greater quantity of pods plant−1. This indicates that the V1 genotype may be a suitable choice for cultivating common beans and highlights the importance of adjusting nutrient levels to ensure sustainable crop management. This study suggests applying 30-60-30 NPK kg ha−1 of fertilizer for genotypes V1 and V3, while genotype V2 should receive 40-80-40 NPK kg ha−1 under rainfed circumstances.

Differential spatial plasticity response in common bean (Phaseolus vulgaris L.) root architecture under water stress is driven by increased root diameter, surface area and volume at deeper layers

Root plasticity enables plants to adapt to spatial and temporal changes in soil resources. In this study, 40 common bean genotypes evaluated for two root and shoot traits under irrigated and water stress. Three genotypes WB-216, WB-N-2, and WB-966 with contrasting plasticity responses were used for in-depth study. Highest positive plasticity for most root traits was found in case of WB-N2 and WB-216, whereas, WB-966 had negative plasticity for all the traits recorded. In terms of spatial plasticity for root traits in three root length sections, WB-216 was positively plastic for root diameter with progressive decrease from top to bottom sections. WB-N2 had positive plasticity values for root diameter, root surface area and root volume. WB-966 had negative plasticity for all the traits. For WB-216, the root diameter increased under drought in S1 but was almost same in bottom sections. In case of WB-N2, there was increase in root diameter in S2 and S3, but for WB-966, root diameter decreased in all sections. Similar trend was observed in all three genotypes for root surface area and volume. We report that major drivers of spatial plasticity of root architectural traits are increased root diameter, surface area and volume at deeper layers.

Conventional management has a greater negative impact on Phaseolus vulgaris L. rhizobia diversity and abundance than water scarcity.

Drought is one of the biggest problems for crop production and also affects the survival and persistence of soil rhizobia, which limits the establishment of efficient symbiosis and endangers the productivity of legumes, the main source of plant protein worldwide. Since the biodiversity can be altered by several factors including abiotic stresses or cultural practices, the objective of this research was to evaluate the effect of water availability, plant genotype and agricultural management on the presence, nodulation capacity and genotypic diversity of rhizobia. A field experiment was conducted with twelve common bean genotypes under irrigation and rain-fed conditions, both in conventional and organic management. Estimation of the number of viable rhizobia present in soils was performed before the crop establishment, whereas the crop yield, nodule number and the strain diversity of bacteria present in nodules were determined at postharvest. Rainfed conditions reduced the number of nodules and of isolated bacteria and their genetic diversity, although to a lesser extent than the agrochemical inputs related to conventional management. In addition, the effect of water scarcity on the conventional management soil was greater than observed under organic conditions. The preservation of diversity will be a key factor to maintain crop production in the future, as problems caused by drought will be exacerbated by climate change and organic management can help to maintain the biodiversity of soil microbiota, a fundamental aspect for soil health and quality.

Genotype by environment interaction and performance stability of common bean (Phaseolus vulgaris L.) cultivars grown in Dawuro zone, Southwestern Ethiopia

Abstract The performance of most crop genotypes varies significantly depending on their genotype–environment interactions. Providing information on high-yielding and well-adapted common bean genotypes in a given environment is crucial for small-holder farmers to boost their productivity. A field trial was conducted at the Gendo and Wara locations over two consecutive seasons to understand genotype–environment interactions on grain yield and to identify and select common bean genotypes that were better adapted and had high yield potential for production. Ten genotypes were evaluated for their performance using a randomized complete block design with three replications. The AMMI and GGE models were used to identify superior genotypes regarding their mean grain yield performance. The AMMI analysis of variance results showed that grain yield was significantly (p ≤ 0.05) influenced by genotype–environment interactions. This shows that genotypes varied in grain yield mean performance across environments, indicating the possibility of selecting suitable genotypes with specific and broad adaptability. The sum of squares factor indicated that grain yield variation was contributed by the genotype (61.0%), followed by the environment (29.80%) and the genotype–environment interaction effect (9.20%) of the total variation. The AMMI and GGE biplot analysis results showed that SER-119 and SER-125 were identified as the best genotypes regarding their mean grain yield performance. Additionally, the genotype selection index analysis result indicated that SER-119 and SER-125 were stable and consistently exhibited high mean performance in all evaluated settings. Therefore, SER-119 and SER-125 are prime candidates for production in various agroecologies suitable for common bean cultivation in Dawuro zones. The use of tools like GGE biplots and AMMI analysis helped visualize the genotype–environment interactions, aiding in the selection of appropriate genotypes for both specific and wide adaptability.

Evaluation of Polyphenols Synthesized in Mature Seeds of Common Bean (Phaseolus vulgaris L.) Advanced Mutant Lines.

This study aimed to investigate the availability of flavonoids, anthocyanins, and phenolic acids in mutant bean seeds, focusing on M7 mutant lines, and their corresponding initial and local cultivars. HPLC-DAD-MS/MS and HPLC-MS/MS were used to analyze twenty-eight genotypes of common bean. The obtained results suggest that the mutations resulted in four newly synthesized anthocyanins in the mutant bean seeds, namely, delphinidin 3-O-glucoside, cyanidin 3-O-glucoside, pelargonidin 3-O-glucoside, and petunidin 3-O-glucoside, in 20 accessions with colored seed shapes out of the total of 28. Importantly, the initial cultivar with white seeds, as well as the mutant white seeds, did not contain anthocyanins. The mutant lines were classified into groups based on their colors as novel qualitative characteristics. Five phenolic acids were further quantified: ferulic, p-coumaric, caffeic, sinapic, and traces of chlorogenic acids. Flavonoids were represented by epicatechin, quercetin, and luteolin, and their concentrations in the mutant genotypes were several-fold superior compared to those of the initial cultivar. All mutant lines exhibited higher concentrations of phenolic acids and flavonoids. These findings contribute to the understanding of the genetics and biochemistry of phenolic accumulation and anthocyanin production in common bean seeds, which is relevant to health benefits and might have implications for common bean breeding programs and food security efforts.

Genetic Diversity, Linkage Disequilibrium, and Population Structure in a Common Bean Reference Collection

An in-depth understanding of the extent and pattern of genetic diversity and population structure in crop populations is of paramount importance for any crop improvement program to efficiently promote the translation of genetic diversity into genetic gain. A reference collection of 150 common bean genotypes selected from the International Center for Tropical Agriculture’s global core collection was evaluated using single-nucleotide polymorphism (SNP) markers to quantify the amount of genetic diversity, linkage disequilibrium, and population structure. The cultivars and landraces of the collection were diverse and originated from 14 countries, and wild accessions were used as controls for each gene pool. The collection was genotyped using an SNP array, generating a total of 5398 locus calls distributed across the entire bean genome. The SNP data quality was checked, and two datasets were generated. The first dataset (Dataset_1) comprised a set of 5108 SNPs and 150 genotypes after filtering for 10% missing alleles and an MAF < 0.05. The second dataset (Dataset_2) comprised a set of 2300 SNPs that remained after removing any null-allele SNPs and LD pruning for a criterion of r2 < 0.2. Dataset_1 was used for a principal coordinate analysis (PCoA), phylogenetic relationship determination, an analysis of molecular variance (AMOVA), and a discriminant analysis of principal components. Dataset_2 was used for a population structure analysis using STRUCTURE software and is proposed for a genome-wide association study (GWAS). The population structure analysis split the reference collection into two subpopulations according to an Andean or Mesoamerican gene pool. The Mesoamerican populations displayed higher genetic differentiation and tended to split into more groups that were somewhat aligned with common bean races. Andean beans were characterized by a larger average LD but lower LD percentage, a small average genetic distance between members of the population, and a higher major allele frequency, which suggested narrower genetic diversity compared to the Mesoamerican gene pool. In conclusion, the results indicated the presence of high genetic diversity, which is useful for a GWAS. However, the presence of significant linkage disequilibrium requires that genetic distance be considered as a co-factor for any further genetic studies. Overall, the molecular variation observed in the genotypes shows that this reference collection is valuable as a genebank-derived diversity panel which is useful for marker trait association studies.