HETROSIS AND COMBINING ABILITY OF SUB TROPICAL MAIZE INBRED LINES

Govind Ballabh Pant University of Agriculture and Technology, India has developed a wide array of subtropical maize (Zea mays L.) germplasm, which are well adapted to the subtropics, resistant to major diseases of maize, mature early and are capable of surviving frost that usually comes late in the cropping seasons. The objective of this study was to determine the combining ability of subtropical maize inbred lines and identify appropriate germplasm for hybrid development. P6 was the highest yielding parent and P2 x P7 was the highest yielding cross. Heterosis for grain yield was high in those involving P6 as a parent. Parents P2, P7 and P8 showed significant positive GCA effects and the rest had significant negative GCA effects for gain yield. Parents P2, P7 and P8 could be used for initiating hybrid development work. For grain yield, P1 x P8 was the best specific combiner followed by P5 x P7, P2 x P7, P3 x P4 and P2 x P8 crosses. P7 and P8 manifested a high positive SCA effect with P2, implying that these two lines combine well with P2.