Genetic Analysis for Resistance to Rust in Soybean Glycine max L Merrill

Abstract

The present investigation was carried out during 2015-17 at the MARS, UAS, newlineDharwad and R and D Farm, Ugar Sugar Works, Ugarkhurd with different experiments. newlineEvaluation of 144 exotic germplasm lines including highly susceptible check JS335 and newlineresistant checks viz., DSb21, EC241780 and EC241778 were evaluated during kharif newline2015 at Dharwad for identification of new sources for resistance to rust and genetic newlinediversity. Based on the resistance reaction, 22 lines which exhibited newlineresistant/moderately resistant reaction were selected and further evaluated to confirm newlinetheir resistant reaction under natural epiphytotic condition at two hotspots for rust viz., newlineDharwad and Ugarkhurd during kharif 2016. Three genotypes viz., DSb21, JS 335 and newlineEC241780 were utilized for hybridization during summer 2015 to study the inheritance newlinepattern for rust resistance and variability. Subsequently, F2 and F3 populations were newlineraised during kharif 2016 and 2017 respectively. In addition to this, validation of newlinemolecular markers linked to rust resistance in F2 population of cross JS335xEC241780 newlinewas carried out. newlineAmong 144 exotic germplasm lines including resistant and susceptible checks, newlineonly one line EC242104 and resistant checks recorded disease grade 1 with highly newlineresistant reaction. The k-means cluster analysis for yield related traits in 144 germplasm newlinelines were grouped into eight clusters. newlineInheritance study revealed that rust resistance is controlled by single dominant newlinegene in all the crosses. The resistant genotypes can be used as a confirmed source of newlineresistance and utilized in future resistance breeding programmes. The F3 families of newlinethree crosses, viz., JS335 x EC241780, EC241780 x JS335 and DSb21 x EC241780 newlinehave generated sufficient variability and also nine superior segregants. newlineStudy on validation of molecular markers, only three markers Satt 361, Satt 275 newlineand Satt 215 exhibited polymorphism. The polymorphic markers were further analysed newlineby single marker analysis which showed a significant association with rust resistance. newline