DETERMINATION OF ENDOGENOUS HORMONE LEVELS IN ASCOCHYTA BLIGHT [Ascochyta rabiei (Pass.) Labr.] SUSCEPTIBLE AND RESISTANT CHICKPEAS (Cicer arietinum L.)

Ascochyta blight, caused by Ascochyta rabiei (Pass.) Labr., is the most important foliar disease of chickpea (Cicer arietinum L.) in many countries. Many studies have been carried out on basis of population biology and host-plant resistance of A. rabiei, but the effect of endogenous plant hormone levels on resistance to ascochyta blight of chickpea has been studied rarely. Therefore, the study was designed to compare endogenous plant hormone levels in ascochyta blight susceptible and resistant chickpea genotypes under ascochyta blight infected conditions. ILC 263, (susceptible to ascochyta blight), FLIP 95-60C and FLIP 98-224C (resistant to ascochyta blight) were used to determine the level of plant hormones; indole-3-acetic acid (IAA), zeatin, gibberellic acid 3 (GA(3)), and abscisic acid (ABA). Concentrations of IAA, zeatin, GA(3) and ABA were markedly increased in pods of resistant genotypes, FLIP 95-60C and FLIP 98-224C. It was suggested that high zeatin and GA(3) concentrations in pods could be detected as biochemical markers to determine resistance to ascochyta blight of chickpea genotypes since the genotypic effect was statistically significant only for zeatin and GA(3). Considering the statistically significant genotypic effects only for zeatin and GA(3), these hormones may be used as biochemical markers to determine resistance to ascochyta blight of chickpea genotypes.