Estimation of Combining Ability Influence on F1Generation for Various Quantitative Traits in-BTand non-BTCotton Gossypium hirsutuml

Abstract

General and specificcombining ability areone of the important plant breeding tools used to compare performances of lines in F1 populationacrossgrowthand yield contributingtraits. Theexperiment was carried out in2014 under the agro-ecological condition of Tandojam, Sindh Pakistan based on a randomized complete block design with four replications. Six parentsand their crosses (nine hybrids), in whichthree femaleparents as lines (Bt-008, IR-1525,and neelam-131) and three male parents as testers (NIA Sadori, NIA Ufaq and NIA Perkh) were evaluated in the study.In F1generation,the meansquares for combining ability for targetedcharacteristicsdisplayed highly significant(p<0.01)generalcombiningabilityeffects in lines for all traits except lint index. But in the case of testers, the GCA effects were significant for sympodial branches plant-1, seed index,and seed cottonyield plant-1and highly significant only for monopodial branches plant-1, ginning outturn%, staple length. While, mean squares values for the interaction of line x tester revealed highly significant specific combing abilityeffects for plant height, monopodial branchesplant-1, bollweight,and GOT%. The two parents Neelam-131 and NIA Ufaq manifested higher general combining ability effects and were good general combiners for yield and yield components and can make a potential material for varietal seed development. Foryield contributingcharacters, crossesIR-1525 ×NIA Ufaq and IR-1525 ×Perkh showed significant SCA effects among the rest of the crosses. Fromthis study, it is suggested that crosses exhibiting greaterSCA valueand parents indicating good GCA valuemust be chosen for enhancementof a specific trait