Dry beans (Phaseolus vulgaris L.) of the Andean gene pool, including red mottled, kidney, cranberry, and yellow seed types are important in Africa and the Americas. Andean dry bean breeding gains have lagged behind those of Mesoamerican beans. This difference may result from a narrower genetic base in the Andean gene pool and reduced breeding efforts. The objective of this research was to establish, genotype, and phenotype a panel of bean germplasm to be used for Andean dry bean breeding. An Andean diversity panel (ADP) was assembled, consisting of 396 accessions and including important cultivars, breeding lines, and landraces that originate mostly from Africa, the Caribbean, and North and South America. The panel was genotyped using the Illumina BARCBean6K_3 SNP BeadChip. The population contained two subgroups: Andean and Mesoamerican bean germplasm. The ADP was comprised of 349 Andean, 21 Mesoamerican, and 26 Andean–Mesoamerican admixed accessions. Most admixed lines came from Africa (12 accessions) and the Caribbean (five accessions). Association mapping was conducted for determinacy. Significant single‐nucleotide polymorphism (SNP) trait associations were found on chromosome Pv01, with the most significant SNP marker being 3.1 kb from the Terminal Flower 1 PvTFL1y gene. The ADP was evaluated for numerous traits in field trials in the United States and Africa. Variability was found for resistance to rust, angular leaf spot and common bacterial blight diseases; tolerance to low soil fertility; cooking time; and other traits that can be used to improve Andean bean germplasm for Africa and the Americas.

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Common bean (Phaseolus vulgaris L.) is an important staple crop for smallholder farmers, particularly in Eastern and Southern Africa. To support common bean breeding and seed dissemination, a high throughput SNP genotyping platform with 1500 established SNP assays has been developed at a genotyping service provider which allows breeders without their own genotyping infrastructure to outsource such service. A set of 708 genotypes mainly composed of germplasm from African breeders and CIAT breeding program were assembled and genotyped with over 800 SNPs. Diversity analysis revealed that both Mesoamerican and Andean gene pools are in use, with an emphasis on large seeded Andean genotypes, which represents the known regional preferences. The analysis of genetic similarities among germplasm entries revealed duplicated lines with different names as well as distinct SNP patterns in identically named samples. Overall, a worrying number of inconsistencies was identified in this data set of very diverse origins. This exemplifies the necessity to develop and use a cost-effective fingerprinting platform to ensure germplasm purity for research, sharing and seed dissemination. The genetic data also allows to visualize introgressions, to identify heterozygous regions to evaluate hybridization success and to employ marker-assisted selection. This study presents a new resource for the common bean community, a SNP genotyping platform, a large SNP data set and a number of applications on how to utilize this information to improve the efficiency and quality of seed handling activities, breeding, and seed dissemination through molecular tools.Electronic supplementary materialThe online version of this article (10.1007/s10722-019-00746-0) contains supplementary material, which is available to authorized users.

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Dry bean (Phaseolus vulgaris L.) is a nutrient‐dense food rich in proteins and minerals. Although a dietary staple in numerous regions, including Eastern and Southern Africa, greater utilization is limited by its long cooking time as compared with other staple foods. A fivefold genetic variability for cooking time has been identified for P. vulgaris, and to effectively incorporate the cooking time trait into bean breeding programs, knowledge of how genotypes behave across diverse environments is essential. Fourteen bean genotypes selected from market classes important to global consumers (yellow, cranberry, light red kidney, red mottled, and brown) were grown in 10 to 15 environments (combinations of locations, years, and treatments), and their cooking times were measured when either presoaked or unsoaked prior to boiling. The 15 environments included locations in North America, the Caribbean, and Eastern and Southern Africa that are used extensively for dry bean breeding. The cooking times of the 14 presoaked dry bean genotypes ranged from 16 to 156 min, with a mean of 86 min across the 15 production environments. The cooking times of the 14 dry bean genotypes left unsoaked ranged from 77 to 381 min, with a mean cooking time of 113 min. The heritability of the presoaked cooking time was very high (98%) and moderately high for the unsoaked cooking time (~60%). The genotypic cooking time patterns were stable across environments. There was a positive correlation between the presoaked and unsoaked cooking times (r = .64, p < 0.0001), and two of the fastest cooking genotypes when presoaked were also the fastest cooking genotypes when unsoaked (G1, Cebo, yellow bean; and G4, G23086, cranberry bean). Given the sufficient genetic diversity found, limited crossover Genotype × Environment interactions, and high heritability for cooking time, it is feasible to develop fast cooking dry bean varieties without the need for extensive testing across environments.

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Virus diseases are among the main biotic factors constraining common bean (Phaseolus vulgaris L.) production in Tanzania. Disease management requires information on types, distribution, incidence, and genetic variation of the causal viruses, which is currently limited. Thus, a countrywide comprehensive survey was conducted. Use of a next-generation sequencing technique enabled simultaneous detection of 15 viruses belonging to 11 genera. De novo assembly resulted in many contigs, including complete or nearly complete sequences of Bean common mosaic virus (BCMV), Bean common mosaic necrosis virus (BCMNV), and Southern bean mosaic virus (SBMV). Some viruses (for example, SBMV and Tomato leaf curl Uganda virus-related begomovirus) were detected for the first time in common bean in Tanzania. Visually assessed virus-like disease incidence ranged from 0 to 98% but reverse-transcription polymerase chain reaction-based incidence of BCMV and BCMNV (7,756 samples) was mostly less than 40%. The Sanger-based nucleotide sequences encoding coat proteins of BCMV and BCMNV isolates were 90.2 to 100% and 97.1 to 100% identical to each other, respectively. Phylogenetic analysis showed that BCMV isolates were more diverse than BCMNV isolates. The information generated in this study will contribute to the development of molecular diagnostic tools and strategies for management of virus diseases nationally and internationally. [Formula: see text] Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

Cereal Chem. 94(1):135-141Dry beans are typically consumed as a whole food, and cooking time is one of the most important processing quality attributes. A panel of eight dry bean entries with variability in cooking time was established, grown in three locations, and used to test the hypothesis that carbohydrate components are major underlying contributors to genetic variability in cooking time. The cooking times ranged from 17 to 160 min. In general, faster cooking bean genotypes had higher levels of soluble dietary fiber in both the raw and cooked samples. Resistant starch levels in the raw beans, although not correlated with cooking time, were of interest because of the large genotypic variability, and they ranged from 1.5 to 35%. One genotype in particular, a yellow bean from Africa, Cebo Cela, had low resistant starch levels in the raw seeds of 1.5-2.5%, whereas average resistant starch levels in the entire panel were 26-30%. Resistant starch levels (3.9-4.2%) in the cooked seed of Cebo Cela were comparable to the other genotypes (3.4-4.3%). Based on light microscopy, the cell walls did not remain intact in the raw milled seed used for the analyses, but they did remain intact in the cooked samples, suggesting the differences in resistant starch in the raw seed are related to starch structure. † Corresponding