Inheritance of Spot Blotch Disease Components in Barley

ABSTRACTA large environmental influence on phenotypic estimates of spot blotch (SB) resistance and the complex polygenic nature of SB resistance in barley (Hordeum vulgare L.) are a limitation to developing resistant cultivars. Component-based polygenic resistance would help in selecting lines with durable resistance. The objective of this research was to investigate the genetics of three important components of resistance to spot blotch caused by Bipolaris sorokiniana (Sacc.) Shoemaker. A total of 124 genotypes were evaluated and two most diverse genotypes each for latent period (LP), number of lesions (NL), and spore production (SP) were selected. To determine the inheritance of LP, NL, and SP, selected diverse genotypes were crossed and advanced to F2, F3, and F4 generations. Inheritance pattern indicated that LP was controlled by 2–3 effective genes, whereas NL and SP were controlled by three genes each. Across the segregating generations, SP and NL showed positive (r = 0.68–0.82) and LP showed negati...