Genetic studies on drought tolerance attributes in Chickpea (Cicer arietinum L.)

In breeding programmes for improving drought tolerance, selection for physiological traits that are closely associated with drought hastens up the progress rather than simply attempting to select high yielding types under drought condition. Genetic studies were conducted utilizing F₂ populations of chickpea crosses JAKI 9218 x ICC 4958, ICC 506EB x ICC 4958, KAK 2 x ICC 4958, JG 11 x ICC 506EB, JAKI 9218 x ICC 506EB, to elucidate the nature of inheritance of leaf chlorophyll content as indicated by the surrogate trait, SPAD Chlorophyll meter reading (SCMR). SCMR values indicate leaf chlorophyll content which in turn is related to leaf ‘N’ status. Frequency distribution graphs of F₂ population of all the five crosses were unimodal, continuous and asymmetric. Variable distribution was observed in five crosses indicating the presence of different allelic frequencies for SCMR in different parental genotypes. The appearance of transgressive individuals in both the extremes, F₂ phenotypic ratio of 1:4:6:4:1 and the measures of skewness and kurtosis in five crosses revealed that the trait leaf chlorophyll in chickpea is governed by a fewer genes which under the influence of modifying factors might have resulted in continuous variation as observed in the trait.