STUDIES ON COMBINING ABILITY AND HETEROSIS FOR YIELD AND ITS COMPONENT TRAITS IN FLUE CURED VIRGINIA (FCV) TOBACCO (NICOTIANA TABACCUM L.)

Abstract

Flue Cured Virginia tobacco (FCV) is an export oriented important commercial crop grown in India. In Karnataka, due to unexpected climate changes and ever increasing cost of cultivation, there is constant reduction in the profitability of tobacco cultivation. Estimating combining ability and heterosis of the parental lines is very important in the development of cultivars with high yield with desirable qualities. Seven advanced breeding lines/ varieties were used to synthesize twenty one half diallel crosses, which were evaluated in a replicated trial for two seasons (kharif of 2016 and 2017). The diallel analysis of variance of two seasons revealed significance of both gca and sca for plant height, green leaf yield and cured leaf yield indicating preponderance of both additive and non additive gene actions. Variety, FCH 222 recorded highest positive gca effect for plant height, cured leaf and bright leaf yield. With respect to specific combining ability (sca), very few cross combinations recorded significant positive sca effect for yield and yield related characters. Only two crosses, JL-32#2 × FCH 249 and Kanchan × JL-32#2 recorded positive sca values for cured leaf yield. Mid parent heterosis was not significant in desirable direction for plant height, number of leaves, bright leaf yield and TGE, however, the cross, JL 53#2 × FCH 249 recorded significant positive mid parent heterosis for green leaf yield and cured leaf yield. The better general and specific combiners identified in the study can be utilised in the future breeding programs