Search Results
You are looking at 1 - 3 of 3 items for :
- Author or Editor: J.R. Myers x
- Journal of the American Society for Horticultural Science x
Plant breeders are interested in developing upright common beans (Phaseolus vulgaris L.) to reduce diseases and permit mechanical harvest, and improve seed quality. Morphological and genetic characteristics of an architectural mutant in common beans were studied. The mutant had shiny, dark green leaves, overlapping leaflets, and short petioles. Branching was nearly absent, resulting in single stemmed plants. Although mutant plants carried Fin for indeterminacy, and plants progressed in flowering from lower to higher nodes, the terminal node was reproductive. This represents a new form of determinacy in common bean. Inheritance studies demonstrated that the mutant syndrome was controlled by a single recessive gene. Allelism tests between the mutant and overlapping leaflets (ol), and dark green savoy leaf (dgs) showed that the mutant was not allelic to either locus. The trait was designated as Topiary with the gene symbol top, describing its compact and neat appearance. Linkage was tested between top and growth habit (fin), shiny leaves, cross-sectional shape of pods, striped pod (C prpst ), and pod suture strings. All genes segregated independently. The genetic merit of the Topiary mutant for improving common beans needs to be investigated, especially the value of single stem growth habit combined with an upright plant habit.
Resistance to bean common mosaic virus (BCMV) strain NY15 (Zaumeyer) and bean common mosaic necrosis virus (BCMNV) strain NL-3 (Drijfhout) was assessed in 98 F5:6 recombinant inbred lines (RILs) derived from a cross between pinto bean (Phaseolus vulgaris L.) cultivars `Olathe' and `Sierra'. `Olathe' has bc-u and bc-12 whereas `Sierra' has no known resistance genes. The differentiation of resistant and susceptible lines was based on visual symptoms, virus titer, and top dry weight. Forty-seven RILs were moderately resistant to NL-3, while 51 RILs were susceptible. This segregation fits a 1 susceptible: 1 resistant ratio characteristic of a single gene. Sixty-nine RILs were susceptible to NY15, while 29 RILs were resistant, which fits a 3 susceptible: 1 resistant ratio characteristic of a two-gene model. Moderate resistance to NL-3 was conferred by bc-12 with or without bc-u present. Bulked segregant and two point linkage analysis identified randomly amplified polymorphic DNA (RAPD) markers linked in coupling to the Bc-1 and Bc-u alleles. The OH141100 RAPD marker was 4.5 cM from the Bc-1 locus. The OC161000 RAPD marker was linked at a distance of 10.9 cM from the Bc-u locus. Multipoint analysis, using segregation data for bc-12 , bc-u, and the two markers, estimated the distance between the Bc-1 and Bc-u loci as 22.8 cM.
Phytochemicals such as phenolic compounds in snap bean (Phaseolus vulgaris) have potential human health benefits. The objectives of this research were to determine the variation in total phenolic content (TPC) measured as gallic acid equivalents (GAEs)—expressed on a fresh weight (FW) basis throughout this study—among a diverse collection of both indeterminate climbing (pole) and determinate (bush) bean cultivars (n = 149) using the Folin–Ciocalteu assay. We also evaluated associations between TPC and phenotypic traits and estimated genotype by environment (G × E) interactions in a subset of the cultivars. The TPC had greater than a 4-fold difference among cultivars and ranged from 0.29 to 1.31 mg·g−1 GAE (mean = 0.49 mg·g−1 GAE). Cultivars were classified into categories of high (≥1.00 mg·g−1 GAE), intermediate (>0.64 to <1.00 mg·g−1 GAE), and low (<0.55 mg·g−1 GAE) TPC. Eighty-four percent, 10%, and 6% of the cultivars fell into the low, intermediate, and high categories, respectively. The pole type cultivars had higher TPC (mean = 0.86 mg·g−1 GAE) when compared with the bush cultivars (mean = 0.47 mg·g−1 GAE). Correlations were observed between TPC and both flower and pod pigmentation. G × E interactions did not occur among pole type cultivars for TPC during 2 years of production, but a significant G × E interaction was observed among bush cultivars. The results demonstrate a wide diversity in snap bean cultivars for TPC, and the pole beans averaged higher TPC than bush bean cultivars. This information should be useful to identify high TPC snap bean cultivars.