摘要 : This study was undertaken to elucidate the nature of inheritance of the two types of drought tolerance in cowpea (Vigna unguiculata). Three cowpea lines, TVu 11986 with Type 1 drought tolerance, Dan IIa with Type 2 drought toleran... 展开 This study was undertaken to elucidate the nature of inheritance of the two types of drought tolerance in cowpea (Vigna unguiculata). Three cowpea lines, TVu 11986 with Type 1 drought tolerance, Dan IIa with Type 2 drought tolerance and TVu 7778 assusceptible to drought, were crossed in all possible combinations. Segregation revealed that drought tolerance is a dominant trait and both Type 1 and Type 2 reactions are controlled by a single dominant gene but the genes are different in the two types.These are designated as Rds 1 (resistance to drought stress) and Rds2. Test of allelism indicated that Type 1 is dominant over Type 2 and the F2 population between the two types segregated 3 Type 1:1 Type 2 plants, indicating that the two genes for drought tolerance are either alleles at the same locus or tightly linked. Efforts are being made to transfer these genes into improved varieties. However, due to allelic relationship, or close linkage, both types of drought tolerance may not be bred in the same cowpea line. 收起