Genetic diversity assessment of Fusarium oxysporum f. sp ciceris isolates of Indian chickpea fields as revealed by the SRAP marker system

An experiment was conducted to study the precise geographical distribution and racial complexity of Fusarium oxysporum f.sp ciceris (Foc) isolates representing 12 states of 4 agro-climatic zones of India at morphological, pathogenic and molecular level. The DNA based sequence related amplified polymorphism (SRAP) markers was employed to differentiate Foc isolates at genome level. The genotypic data output of the isolates was examined for diversity parameter as marker's Polymorphic percentage (PM %), Polymorphic Information Content (PIC), Marker Index (MI) and Gene Diversity Index (DI). As a result, 15 primers used in this study could generated total of 154 reproducible alleles ranging from 100-2100 bp (average allele per marker 10.26) in size, of that 149 (97%) were found to be polymorphic. The neighbor-joining analysis effectively classified the isolates of North East Plain Zone (NEPZ), Central Zone (CZ), North West Plain Zone (NWPZ) and South Zone (SZ) into four clusters. In summary, DNA based marker analysis could differentiate as per isolates geographical location, however pathogenic interaction of isolates from same geographical location could not match the genetic differentiation. Accordingly, considering the present complexity in racial profile, precise classification based on homologs virulence genes specific to races would give a more meaningful in correlating isolates with their native geographical distribution and helps in future resistance breeding programs for sustainable management of vascular wilt disease.