Abstract:

Landrace genotypes which are important gene resources, are used as starting material in breeding studies. Common beans are sensitive to abiotic stress. For this reason, early screening tests performed under stress conditions will provide convenience for breeders to perform the breeding process accurately and fast. In this study, an early-stage drought stress index was formed for fifteen genotypes whose salt tolerance indices were determined previously. For this purpose, genotypes were exposed to four different drought stresses until the first flowering period [25% (I25), 50% (I50), 75% (I75), and 100% (I100)]. As drought-related plant growth parameters to determine the drought adaptability of genotypes shoot length (cm), root length (cm), shoot fresh and dry weight (g), root fresh and dry weight (g), leaf width and length (cm), stem diameter (cm) and stomatal conductance were measured. Later, genotypes were classified according to the drought stress index. It was determined that genotypes and drought stress had a statistically significant effect on all parameters examined, and Genotype x Drought interaction for all properties to be significant at the 0.01 level. According to the drought stress index data, three of the genotypes (ADY4, AGB1 and AGB5) were moderately sensitive and twelve (AGun6, AGun19, AGun25, BKara1-A, Bkara2, BY4, BY24, ISGa1, ISGa7, ISGa10, IYoz10 and IYoz14) were sensitive. In conclusion, although the studied genotypes were not drought tolerant, this was determined in the early stage using the drought tolerance index. This study is important as an example of the early classification of vegetable genotypes using drought tolerance indexes in future studies.

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