Assessment of genetic diversity of Iranian Ascochyta rabiei isolates using rep-PCR markers

摘要

Genetic diversity and population structure among 29 isolates of Ascochyta rabiei (AR) obtained from diseased chickpea plants in six different geographical origins in Iran was characterized by MAT and rep-PCR (BOX/ERIC/REP) markers. Both mating types were found in all six populations, and the frequencies of mating types were variable between populations. The majority of the isolates belonged to Mat1-1 (58.12%) with the remainder (41.88%) being Mat1-2. A dendrogram was calculated with Jaccard's similarity coefficients with unweighted pair group method clustering (UPGMA) for the combination of rep-PCR results, AR strains were differentiated into four clusters (A-D) at 60% similarity level. ERIC, REP and BOX showed a total of 19, 37 and 24 alleles per locus, respectively. Gene diversity (He) and Shannon's information index (I) were the highest in the REP (He = 0.82; I = 2.11), while the lowest values were estimated for the ERIC (He = 0.42; I = 1.3). Our result showed that among the three techniques studied, REP-PCR produced the most complex amplified banding patterns, which reflected a high degree of diversity among the Iranian AR strains. ERIC-PCR was the least discriminating method, and BOX-PCR was intermediate. To the best our knowledge, this is first study of assessment of genetic diversity of AR isolates by rep-PCR markers.