Genetic evaluation of barley (Hordeum vulgare L.) germplasm for resistance components of spot blotch disease

Abstract

Spot blotch caused by Bipolaris sorokiniana is an important fungal disease of Barley in warm humid areas of the world. In present study, 124 genotypes that includes 122 un-adapted germplasm accessions and 2 cultivars of barley were evaluated for three years, to select resistant and susceptible accessions based on five components of spot blotch resistance viz., disease severity, latent period, spore load, number of spots and incubation period. Significant differences were observed among the evaluated accessions for all of the components of resistance. A significant positive correlation was recorded between disease severity, number of spots, and spore load while a significant negative correlation of disease severity was recorded with latent period and incubation period. Multiple regression analysis revealed that number of spots contributed maximum followed by latent period, spore load and incubation period towards the variation in disease severity. Clustering of accessions based on different components identified three groups. Based on the studied components, accessions BCU422, BCU1204 and BCU5092 demonstrated good performance, while BCU711, K603 and RD2506 were the most susceptible to spot blotch pathogen. Identified accessions BCU422, BCU1204 and BCU5092 can be recommended for use in breeding programs that aim to generate barley genotypes resistant to Bipolaris sorokiniana.

Keywords

• Barley
• spot blotch
• Bipolaris sorokiniana
• germplasm
• disease severity.