ABSTRACT

In the present study 105 hybrids were derived by crossing 35 inbred lines with three diverse testers CML286, CML451 and RCD76 in Line × tester design. These hybrids along with their parents and checks evaluated in alpha lattice design at MARS, UAS Dharwad for their combining ability, heterosis, association among traits and disease reaction against turcicum leaf blight.
The analysis of variance demonstrated significant differences among the crosses indicating the existence of genetic variability. The magnitude of SCA variances was higher than GCA variances for all the traits except days to 50 per cent anthesis, days to 50 per cent silking and days to maturity reflecting the predominance of non-additive gene action in governing these traits. Analysis of combing ability showed that lines viz., VL154542, VL184899, VL2280 and VL18323 had significant gca effect for yield and yield related traits. Among the hybrids, VL181580 × CML45, VL19532 × CML451 and VL154542 X CML286 recorded highest significant sca effect for grain yield. Based on per se performance, VL154542 × CML286, VL184899 × RCD76 and ZL18869 × RCD76 were top performing hybrids for grain yield.
Correlation study revealed that grain yield had significant and positive association with all traits except days to 50 per cent anthesis, days to 50 per cent silking and days to maturity at both genotypic and phenotypic levels.
Among the lines, VL18262 and VL192697 showed resistance to turcicum leaf blight whereas hybrids VL154542 × CML286, VL184899 × RCD76 had high grain yield and resistance to turcicum leaf blight. The best hybrid identified from the present study was VL154542 × CML286 which recorded highest mean grain yield of 109 q/ha and showed significant standard heterosis over local check GH-150125 (34.57%) and national check NK-6240 (28.24%) besides recording resistance to turcicum leaf blight.