STUDIES ON THE GENETICAL COMPONENTS USING THE TOP CROSS MATING DESIGN IN MAIZE (Zea mays L.)

Abstract

The field experiments were carried out in two successive summer seasons 2014 and 2015 at the experimental farm of the Faculty of Agriculture, Menoufia University, in El-Raheb, Egypt to evaluate yellow inbreed lines of maize through line x tester analysis. A total of twenty-five (Zea mays L.) yellow S4 lines were used to establish the experiment materials. Two testers of yellow maize were used in this investigation to make all possible line x tester crosses. The two testers used in this study were Giza 658 and Sids 3120. Two check verities were used in this investigation their names are single cross Giza 168 and Giza 176. The most important results For grain yield (ard/fed), twelve, four and eight top crosses gave higher grain yield compared with the highest check Giza 168 under HD, ND and combined data, respectively. The top crosses L3 x T1 and L3 x T2 were the highest values for grain yield under this study. Therefore, the inbred line L3 was useful in maize breeding programs. The inbred lines L3, L4, L9, L11 and L14 desirable significant GCA effects for grain yield (ard/fed). Thirteen top crosses showed significant positive SCA effects for grain yield (ard/fed) under HD, ND and their combined. Also, the top crosses L1 x T2 and L11 x T2 were significant under high plant density. The top cross L3 x T1 was the higher value of heterosis relative to two check varieties for grain weight per ear weight and grain yield. Also, eight top crosses were highly significant heterosis relative to two check varieties for grain yield (ard/fed).