High temperatures (>30°C day and/or >20°C night) in tropical lowlands and production areas in temperate zones reduce yield and quality in common bean (Phaseolus vulgaris L.). Tepary bean (P. acutifolius A. Gray) is a crop adapted to hot arid climates and is grown in the American Southwest and parts of Mexico under temperatures that are too high for pod formation in common bean. Interspecific hybridization may enable transfer of heat tolerance traits from tepary bean to common bean. Twenty-five tepary bean plant introductions (PI) with the ability to set seed under controlled-environment conditions were evaluated under high (35 °C day/32 °C night) and control (27 °C day/24 °C night) temperature treatments during reproductive development. Four accessions (PI 200902, PI 312637, PI 440788, and PI 440789) exhibited normal pod formation and comparatively high yield when exposed to high temperature, while common bean controls displayed zero pod and seed set. These four PIs showed a mean decrease in seed yield of 72.9% from control to high temperature treatment, as compared to 90.3% among all tepary beans. These accessions were hybridized with the dry bean cultivar `ICA Pijao', and the heat-tolerant bean cultivars `Carson' and `CELRK' and breeding line `Cornell 503'. Immature embryos were cultured to obtain interspecific hybrids. Fertility of F1 hybrids and generation of backcrosses are discussed.
Katy M. Rainey* and Phillip D. Griffiths
Phillip N. Miklas, Kenneth F. Grafton, and Phillip E. McClean
We investigated the partial physiological resistance (PPR) of common beans (Phaseolus vulgaris L.) to white mold disease caused by Sclerotinia sclerotiorum (Lib.) deBary. The activity of phenylalanine ammonia-lyase (PAL) was measured in detached stems inoculated with a growing mycelium of the pathogen. Noninoculated detached stems and whole plants were included as controls. Five bean cultivars-Upland, Bunsi, Sierra, UI-114, and Montcalm-and one breeding line-NY 5394-were tested; all varied in PPR to white mold disease. Greater PAL activity in the resistant NY 5394 than in the susceptible `Upland' suggests that PAL activity may be involved in the PPR of common beans to S. sclerotiorum.
Carol A. Miles
Commercial edamame (Glycine max) varieties and advanced edamame breeding lines from the Asian Vegetable Research Development Center (AVRDC) were tested for adaptability to southwest Washington. Edamame, or green vegetable soybeans, are specialty varieties of soybeans that are eaten at the green stage as a vegetable. For the vegetable market, 25 beans must weigh at least 20 g. Experimental procedure was a randomized complete block design with four replications. Recommendations from AVRDC for plant spacing and fertilizer application and timing were followed. In 1995, 13 commercial varieties and 10 AVRDC breeding lines were tested in an on-farm location in Chehalis. At the same location in 1996, 10 of these commercial varieties were again tested along with an additional six commercial varieties. Also in 1996, 12 new AVRDC breeding lines were tested along with the single line that was selected in 1995. Both years, all commercial varieties were harvested more than 40 days later than their advertised days to maturity. Three commercial varieties, White Lion, Shironomai, and Butterbeans, were high-yielding in both years. In 1995, one AVRDC breeding line was selected in Chehalis, and in 1996 five additional AVRDC breeding lines were selected. Earliness is a key factor affecting suitability of commercial varieties and breeding lines to the Chehalis area. In this region, irrigation also appears essential for production of large beans for the vegtable market. Pod weight was not a good indicator of bean weight. Seed was collected in Chehalis from AVRDC breeding lines for use in future trials.
J.M. Quintana, H.C. Harrison, J. Nienhuis, J.P. Palta, and K. Kmiecik
This study was designed to compare snap and dry beans (Phaseolus vulgaris L.) for pod Ca concentration, and to identify genetic resources that might be useful in breeding programs directed to increase Ca concentration in bean pods. Pods from eight snap bean and eight dry bean cultivars were evaluated for Ca concentration during 1995 and 1996 at Hancock, Wis. A randomized complete-block design was utilized with three replications in 1995 and six in 1996. Beans were planted in June and hand-harvested in August for both experiments. Soil Ca at planting time was 580 mg·kg–1 in 1995 and 500 mg·kg–1 in 1996. No additional Ca was added. Plots consisted of 10 plants each. At harvest, a pooled sample of 10 to 15 size no. 4 pods was collected from each plot. Atomic absorption spectrophotometry was used to determine Ca content. Significant differences (P ≤ 0.01) were detected among and within bean types (dry and snap). Although bean type × year interaction was nonsignificant, a strong year effect was observed (P ≤ 0.01). Snap beans (4.6 ± 0.7 mg·g–1 dry weight) had significantly higher pod Ca concentration than did dry beans (4.2 ± 0.6 mg·g–1 dry weight). Within snap beans, `Checkmate' had the highest pod Ca concentration (5.5 ± 0.3 mg·g–1 dry weight) and `Nelson' the lowest (3.8 ± 0.3 mg·g–1 dry weight). Within dry beans, `GO122' had the highest (5.1 ± 0.4 mg·g–1 dry weight) and `Porrillo 70' the lowest pod Ca concentration (3.6 ± 0.3 mg·g–1 dry weight). Six cultivars had pod Ca concentrations significantly (P ≤ 0.01) higher than the overall mean (4.4 ± 0.3 mg·g–1 dry weight).
F.A. Bliss, J.C. Rosas, and P.A.A. Pereira.
94 ORAL SESSION 26 (Abstr. 194–201) Vegetables: Breeding for Disease Resistance
James D. Kell
55 COLLOQUIUM 2 (Abstr. 995-999) Classical and Molecular Approaches to Breeding Horticultural Plants for Disease Resistance
D. S. Nuland, D. T. Lindgren, D. P. Coyne, and J. R. Steadman
The objective of this cooperative system is to establish reaction of both private and public developed dry beans to common blight, rust, and white mold as well as to document performance in the absence of disease constraints. All commercially available Great Northerns and Pintos plus entries from the Cooperative Dry Bean Nursery and selected entries from public and private breeding programs are included. Entry number ranges from 70 to 80 each year. Annual results are published in “Biological and Cultural Tests for Control of Plant Diseases”.
Mark J. Bassett
A new gene for flower color pattern, designated white banner (WB), appeared in material derived from the cross `Harvester' snap bean (Phaseolus vulgaris L.) × Plant Introduction (PI) accession 273666 of scarlet runner bean (P. coccineus L.). The WB character has a white banner petal and pale violet wings (veronica-violet 639/2). The inheritance of the mutant was studied in crosses involving dry bean breeding line 5-593, which has bishops-violet (wild-type) flowers, and genetic stocks v BC2 5-593 (white flowers) and blu BC2 5-593 (blue flowers). Segregation in F2 and F3 progenies from the cross v BC2 5-593 × WB supported the hypothesis that WB is controlled by a single recessive gene that is nonallelic with the V locus. An allelism test with blu BC2 5-593 gave evidence that WB is not allelic with the blu locus. The gene symbol wb is proposed for the gene producing WB.
G. Acquaah, T.G. Isleib, and A.E. Ferguson
The future of molecular markers in common bean (Phaseolus vulgaris L.) breeding and genetics lies in the discovery of more useful markers than now available. One-dimensional SDS/PAGE analysis revealed four phaseolin types, “S,” “T,” “C,” and “H,” in proportions of 23.5%, 49.2%, 24.8%, and 2.5%, respectively. Molecular heterogeneity of phaseolin subunits was not apparent. On the basis of the phaseolin types and seed size, ≈75% of the landraces from Malawi probably were introduced from the Andean primary center of common bean domestication. The remaining 25% were small-seeded and probably originated from the Meso-American center of domestication of common bean. In Malawi, some amount of hybridization has occurred between genotypes from the two centers of domestication.
Ana B. Monteagudo, A. Paula Rodiño, Margarita Lema, María De la Fuente, Marta Santalla, Antonio M. De Ron, and Shree P. Singh
fellowships from the Galician Government and the University of Santiago de Compostela to Ana B. Monteagudo. We are also grateful to the CRF-INIA (Alcalá de Henares, Spain) for supplying seeds of some common bean accessions, the University of Idaho and Seminis