Inheritance and biochemical basis of yellowing of apical leaves: a unique trait in chickpea (Cicer arietinum L.).

A unique trait, i.e. yellowing of apical/young leaves in response to low temperature and high relative humidity was identified in a chickpea genotype, ICCX110069. To determine inheritance pattern of this trait, ICCX110069 was crossed to four other genotypes, GL14050, GL14049, GL14059 and SAGL152117, that exhibited normal green apical leaves under similar environmental conditions. The F1, F2, F3, BC1F1 and BC1F2 generations were generated. A ratio of 13 normal green leaf: three yellow leaf was found to be the best fit, indicated digenic gene action with suppressor effect of normal green leaf over the expression of yellowing of apical/young leaf trait. The chlorophyll content was significantly lower, while guaiacol peroxidase activity was significantly higher in yellow leaves of ICCX110069 as compared to green leaves of the same genotype and of GL14049, indicating the competence of antioxidative defence mechanism involved with the expression of this trait.