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The seed yield potential of Phaseolus genotypes varies according their genetic background, environmental conditions, agronomic management, presence of pathogens, and/or their interactions. We evaluated the agronomic performance of 27 common bean (Phaseolus vulgaris L.) and three tepary bean (P. acutifolius A. Gray) genotypes and their response to ashy stem blight (ASB) caused by Macrophomina phaseolina (Tassi) Goidanich. The 30 bean genotypes were planted in Isabela and Lajas, Puerto

Pigeonpea [Cajanus cajan (L.) Mill.] cultivar 'Lázaro' (Reg no. CV-331, PI 692612) was developed in the United States at the Isabela and Lajas Research Substations at the University of Puerto Rico in collaboration with researchers at the University of California, Riverside. Lázaro was derived from the bi-parental cross '2B-Bushy'/OP-61 and traces back to the selection of F 2 individual plants insensitive to long daylength (>12 h) and advanced by a combination of pedigree and bulk breeding methods. Lázaro is photoperiod insensitive, and its yield performance was tested in six environments with checks in Puerto Rico and under furrow and drip irrigation systems in California in 2017 and 2018. Lázaro has a determinate growth habit, initiates flowering from 69 to 94 d, reaches harvesting maturity between 130 to 149 d, and has a small beige seed (17 g per 100 seeds). Mean seed yield varied from 338 to 1,091 kg ha −1 in Puerto Rico and >3,300 kg ha −1 in California. Furthermore, Lázaro can be planted year-round compared with cultivars 'Cortada', 'Guerrero', and 'ICP 7035', which are photoperiod sensitive and thus only recommended for planting under short-daylength conditions.

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Ashy stem blight (ASB), caused by the fungus Macrophomina phaseolina (Tassi) Goidanich is an important disease of the common bean (Phaseolus vulgaris L.). It is important to identify quantitative trait loci (QTL) for ASB resistance and introgress into susceptible cultivars of the common bean. The objective of this research was to identify QTL and single nucleotide polymorphism (SNP) markers associated with ASB resistance in recombinant inbred lines (RIL) derived from a cross between BAT 477 and NY6020-4 common bean. One hundred and twenty-six F6:7 RIL were phenotyped for ASB in the greenhouse. Disease severity was scored on a scale of 1–9. Genotyping was performed using whole genome resequencing with 2x common bean genome size coverage, and over six million SNPs were obtained. After being filtered, 72,017 SNPs distributed on 11 chromosomes were used to conduct the genome-wide association study (GWAS) and QTL mapping. A novel QTL region of ~4.28 Mbp from 35,546,329 bp to 39,826,434 bp on chromosome Pv03 was identified for ASB resistance. The two SNPs, Chr03_39824257 and Chr03_39824268 located at 39,824,257 bp and 39,824,268 bp on Pv03, respectively, were identified as the strongest markers associated with ASB resistance. The gene Phvul.003G175900 (drought sensitive, WD repeat-containing protein 76) located at 39,822,021 – 39,824,655 bp on Pv03 was recognized as one candidate for ASB resistance in the RIL, and the gene contained the two SNP markers. QTL and SNP markers may be used to select plants and lines for ASB resistance through marker-assisted selection (MAS) in common bean breeding.