GENETIC ANALYSIS OF STAY GREEN AND ITS COMPONENT TRAITS IN SORGHUM Sorghum bicolor L Moench

Abstract

An investigation was carried out to understand the genetics and association of staygreenness with yield and its attributing traits and also to study the variability for yield and newlinestress tolerant traits in popular but stress (terminal drought) susceptible varieties GS-23 and newlinestay green genotypes K260 and K359w at different generations of crosses during rabi season newlineof 2017-18 at ARS, Kalaburgi and Hagari. The experimental material consisted of three newlineinbred lines of which GS-23 (P1) is a non-stay green lines used as female parent, which are newlinecrossed with two stay green donor lines K260 (P2) and K359w (P3) received from ICRISAT, newlineHyderabad. These lines were used to develop experimental material which comprised of six newlinebasic generations P1, P2, F1, F2, BC1 and BC2 of two crosses GS-23 × K260 and GS-23 × newlineK359w. The analysis of variance for all the treatments including checks revealed significant newlinedifferences among the treatments for all the traits. Analysis of variance among the six newlinegenerations of a cross GS-23 × K260 revealed significant treatment differences all the traits newlineexcept for days to panicle emergence, days to 50 per cent flowering and days to maturity. The newlinesignificance of scaling test except for days to flowering indicates that the simple additivedominance model or simply additive model is not adequate to explain the gene effects of stay newlinegreen and grain yield component traits in sorghum. With respect to stay-green, comparison newlinebetween generation means revealed non-additive gene action for trait inheritance of stay newlinegreen traits. Stay green inheritance studies in F1, F2 and F3 breeding behaviour showed that newlinethe dominant gene action plays major role in controlling the stay green trait in both the newlinecrosses and stay green trait is dominant across generations in nature of expressing at maturity newlinelevel too, thus giving the sorghum crop to with stand physiological stress under drought newlineconditions by staying green. The results of this study provide valuable insights into the use of newlineSNPs in backcross breeding and lay the fo