Genetic diversity analysis of a world-wide collection of Ascochyta rabiei isolates using sequence tagged microsatellite markers

Abstract

A previously characterized compound microsatellite locus ARMS1, containing penta-and decameric repeat units, has been reported to reveal genetic diversity in Ascochyta rabiei (Pass.) Labr. isolates. Therefore, 37 isolates of Ascochyta rabiei collected from different states of India and 38 isolates from fifteen other countries in the world were examined for their diversity at this locus. Twenty-six alleles on the basis of size (228-451 base pairs) were detected in the world isolates examined, while 15 alleles (287-418 base pairs) were observed in isolates from the Indian subcontinent. To the best of our knowledge, this study is the first to demonstrate diversity in representative Ascochyta rabiei isolates from different parts of the world at the ARMS1 locus.

Assessment and comparison of AFLP and SSR based molecular genetic diversity in Indian isolates of Ascochyta rabiei, a causal agent of Ascochyta blight in chickpea (Cicer arietinum L.)

“…1 Grouping of Ascochyta rabiei isolates based on genotyping data for 12 SSR markers alleles with an average of 2.42 alleles per locus. In contrast to the present study, Barve et al (2004) reported up to 15 alleles at one SSR locus. It is noteworthy here that Barve et al (2004) analyzed a larger collection of AB isolates (37 isolates from India and 38 isolates from 15 other countries) at a highly polymorphic SSR locus (ARMS1) known for the A. rabiei genome.…”

“…In contrast to the present study, Barve et al (2004) reported up to 15 alleles at one SSR locus. It is noteworthy here that Barve et al (2004) analyzed a larger collection of AB isolates (37 isolates from India and 38 isolates from 15 other countries) at a highly polymorphic SSR locus (ARMS1) known for the A. rabiei genome. Similarly, Geistlinger et al (2000) reported up to 14 alleles per locus among 22 isolates representing the worldwide collection of AB isolates.…”

“…Although an SSR-based oligonucleotide fingerprinting approach has been used in several studies to assess the molecular diversity in AB isolates (Weising et al 1991;Morjane et al 1994;Geistlinger et al 1997;Udupa et al 1998), the sequence tagged microsatellite (STMS)-based Barve et al 2004). STMS-based SSR markers have been proven very useful in plant genetic and breeding because of being co-dominant, multi-allelic, and locus-specific in nature (Gupta and Varshney 2000).…”

“…Only a few molecular genetic studies have been conducted to assess the diversity in AB isolates in different parts of world by using SSR-based oligo-fingerprinting (Weising et al 1991;Morjane et al 1994;Geistlinger et al 1997;Udupa et al 1998;Jamil et al 2000;Barve et al 2004), AFLP (Peever et al 2004), RAPD (Santra et al 2001;Chongo et al 2004), and SSRs . In some studies, comparative assessment of genetic diversity, based on different marker systems, i.e., oligo-fingerprinting, RAPDs, and AFLPs, has been carried out (Udupa et al 1998;Peever et al 2004).…”

Diagnostics, genetic diversity and pathogenic variation of ascochyta blight of cool season food and feed legumes

“…However, the use of dominant molecular markers used in these analyses and in most cases the small sample sizes resulted in a lack of knowledge on the population structures. Barve et al (2004) used a specific microsatellite locus to identify a high level of genetic diversity in A. rabiei isolates from 16 countries. Analysis of isolates of A. rabiei from the USA using AFLP, SSR markers and the mating type locus (MAT1-1) indicated that most of the diversity of A. rabiei originated from the introduction of a large number of isolates into the USA between 1983 and 1984 ).…”