Phylogenetic relationship among Indian population of Fusarium oxysporum f. sp. lentis infecting lentil and development of specific SCAR markers for detection.

The present study was taken up to understand the phylogenetic relationship using ITS and TEF markers among 22 isolates of Fusarium oxysporum f. sp. lentis (Fol) causing lentil wilt belonging to eight races isolated from different geographic locations of India and to develop specific markers for its detection. The nucleotide sequences of ITS region varied from 490 to 560 bp whereas, 670-725 bp for TEF 1α. The phylogeny analysis revealed that the isolates were more than 98% similar based on the neighbour joining analysis and were grouped into two major clusters in both ITS and TEF. The first major cluster of ITS had twenty isolates whereas for TEF, there were 15 isolates. Two sets of SCAR markers MS1 (162 bp) and MS2 (125 bp) were designed and synthesised. These markers were used against race representative Fol isolates for amplification. While, MS 1 marker was able to detect the genomic DNA up to 0.1 ng, MS 2 could detect the Fol genomic DNA up to 0.05 ng. The specificity of these two markers to detect Fol and their inability to amplify most common lentil pathogens (Rhizoctonia solani, R. bataticola, Sclerotium rolfsii, Sclerotinia sclerotiarum, and Aschochyta rabiei) makes them a reliable tool for detection. The phylogenetic analysis is helpful in the understanding of variability in Fol populations and the SCAR markers help in rapid and reliable detection of an important pathogen of lentil.