Phenotypic and Genetic Variation Studies in Finger Millet Genotypes to Blast Disease Caused by Pyricularia grisea

The most detrimental disease of finger millet (Eleusine coracana) is blast caused by Pyricularia grisea inflicting substantial yield losses. This study evaluated 100 finger millet genotypes from a core collection for disease response to leaf, neck and finger blast. Good phenotypic variability in the genotypes was recorded for blast reactions. None of the accessions was resistant to leaf blast; however, 12 and 27 accessions were resistant to neck and finger blast, respectively. A total of 28 accessions showed resistance to both neck and finger blast. A significant positive correlation was observed between neck and finger blast. Genotyping of 50 accessions differing in disease reactions to neck blast was performed using 30 SSR markers 17 of which proved to be polymorphic. A total of 51 alleles were detected with the mean value of 2.55 alleles per locus. The PIC values of the polymorphic SSR markers ranged from 0.03 to 0.98, and the dendrogram grouped these genotypes in 13 clusters. Cluster I and II comprised of resistant accessions, whereas cluster VIII formed the susceptible group. SSR markers UGEP 76 and UGEP 102 consistently produced bands in neck blast susceptible and highly susceptible germplasms, indicating their probable association with neck blast susceptibility gene(s). Our results showed that the core collection has appreciable diversity for blast reactions both phenotypically and genotypically.