Identifications of charcoal resistance hybrids among sunflower genotypes by using line by tester analysis

Abstract

Sunflower is an important oilseed of the world and yield of the sunflower has been threatened by the biotic and abiotic factors under current scenario of global climate change. Charcoal rot is a peculiar disease of tropical and subtropical climate and is characterized by the presence of lesions on stem which causes wilting and premature lodging of stem. Introgression of disease resistant genes is the only solution to combat disease. To find out charcoal resistant lines this research was carried out in the department of Plant Breeding & Genetics, College of Agriculture, University of Sargodha, Pakistan during 2021-23. Four (04) charcoal resistant inbred lines (B-208, B-124, B-224, B-112) were crossed with the four (04) male fertility restorer lines (RH.334, RH.456, RH.459, R.SIN.82) in line × tester fashion to yield 16 half sib cross combination. Plants were inoculated at the base of stem with the concentration of 3 basidium µL-1, after 30 days after sowing. Crosses were found significantly different for the incidence of charcoal rot resistance. However, C.112 ×RSIN.82 was found to be less infested and considered as resistant hybrids. Moreover, cross combinations C.112 ×RSIN.82 and C.208 ×RH.344 showed significant negative heterosis and complete to overdominance toward resistant breeding lines. Heterosis estimates were low and show high magnitude of dominance variance than additive variance for disease resistance. Breeding lines B-112, B-208 and RSIN.82 had significant general combining ability effects and may be exploited in breeding program.