aradhnasagwal31@gmail.com, rsb1965@gmail.com and ravindrakumarbhu@gmail.com

Spot blotch is most catastrophic disease in barley caused by hemi-biotrophic and aggressive fungus Bipolaris sorokiniana (Sacc.) Shoemaker. The disease is most damaging under warm temperature and intermittent rains. The diseased barley leaves across the locations in India were collected, the isolates of pathogen Bipolaris sorokiniana was isolated and purified.

Genetic variability of 30 Bipolaris sorokiniana affecting barley was studied using ITS gene rDNA sequencing. The positive amplicons were purified by using FavorPrepTM GEL/PCR Purification kit. The purified product was sequenced with Sanger’s method DNA sequencing. The sequences obtained were blast on NCBI, upon confirmation sequences were submitted to nucleotide data base of NCBI. The same sequences were processed for multiple sequence alignment using clustal W and phylogenetic tree was constructed using Neighbors joining method in MEGA-X software.

The dendrogram generated grouped them to clusters and revealed diversity among isolates. Bs 29 isolate collected from Ludhiana, Punjab (Accession No. OQ955738) was found to be the most diverse among the isolates. It was also found that Bs 29 was most virulent among all isolates having shortest incubation and latent period.

The sequences of most pathogenic isolates submitted to nucleotide data base of NCBI were given Accession No. (OQ955726, OQ955727, OQ955728, OQ955729, OQ955730, OQ955731, OQ955732, OQ955733, OQ955734, V OQ955735, OQ955736, OQ955737, OQ955738, OQ955739). Thus, the understanding of pathotypes diversity helped in identifying the genes that are to be deployed for development of resistant barley cultivars.

Keywords: Barley, Bipolaris sorokiniana, diversity, Spot blotch