|Singh, Shree - UNIVERSITY OF IDAHO|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 18, 2001
Publication Date: August 1, 2002
Interpretive Summary: As much as 60% of the world's common bean production is on soil that has either a nutrient deficiency or toxicity. Zinc deficiency is common to many production areas. We evaluated the inheritance of zinc deficiency in common bean genotypes and found that a single dominant gene controlled the susceptibility to zinc deficiency in the common bean (Phaseolus vulgaris L.). This suggests that molecular markers might be tightly linked to this trait to allow identifying susceptible genotypes and subsequent transfer of zinc deficiency resistance. Growers could then plant resistant genotypes on problem soils and avoid needless zinc fertilization costs.
Technical Abstract: Cultivated soils often are either deficient or possess toxic concentrations of one or more mineral elements that adversely affect emergence, growth, maturity, productino potential, and/or nutritional quality of common bean (Phaseolus vulgaris L.). Our objective was to study the inheritance of resistance to soil Zn deficiency. The resistant 'Matterhorn' was crossed with the susceptible 'T-39'. The first generation was backcrossed to Matterhorn (FM) and T-39 (FT), and advanced to the second generation. The two parents were evaluated in a Zn deficient field trial at Kimberly, Idaho in 2001. Plants were classified as tall-healthy or stunted with chlorotic leaves. Leaves were sampled from the two types of plants at flowering and analyzed for Zn concentration. The tall plants had an average leaf Zn concentration of 22.5 mg/kg. In contrast, stunted plants had a Zn concentration of 15.0 mg/kg. All first generation plants were tall resembling Matterhorn, except that unlike Matterhorn (white flowers and seeds) they had purple flowers and black shiny seeds. Thus, the resistance to Zn deficiency was dominant. A segregation of 45 resistant to 20 susceptible plants was observed in the second generation, giving a good fit to 3 R:1 S. All plants in FM were resistant. In FT, 142 resistant and 139 susceptible plants were observed, giving a ratio of 1 R to 1 S. This supports a single dominant gene controlling soil Zn deficiency resistance. The symbol Znd is proposed for the dominant allele controlling resistance to soil Zn deficiency, and znd for its susceptible counterpart.