Molecular variability studies in Indian isolates of Fusarium oxysporum f. sp. ciceri using microsatellites

摘要

Fusarium oxysporum f.sp. ciceri is a serious pathogen of chickpea (Cicer arietinum L.). Although several wilt resistant lines are available, fall in their resistance is phenomenal. Thus it is Important to characterize the pathogen races depending upontheir pathogenecity. Molecular pathotyping is advantageous since it is environmentally independent and less time consuming unlike pathotyping involving differential cultivars. 34 isolates representing the hot spots in India have been taken for the study. Standardization of the enzyme-probe combinations were done using four standard races. 11 different microsatellites (di, tri and tetra nucleotide repeals) were used In combination with nine different restriction enzymes (hexa, penta and tetra cutters).Hybridization patterns revealed the presence of different repeat motifs in the Foc genome. The oligos (ATC)_5, (ACT)_5, (ACG)_5, (ACC)_5, (AGC)_5, (CT))_(10), (ACA)_5 and (GATA)_4 detected variability in the four standard races and fingerprint patterns were obtained using specific enzyme-probe combinations. In general, hexacutters gave a better hybridization pattern as compared to tetracutters. Based on banding patterns obtained, Foc3 was significantly different from the other 3 races. (ATC), and (ACG),revealed the presence of some specific bands in Foc2. This study highlights the use of microsatelllte markers in variability studies of Fusarium oxysporum f.sp. ciceri.