Combining ability of grain yield and agronomic traits in diverse maize lines with maize streak virus resistance for Eastern Africa region

Abstract

Combining ability of inbred lines is important information in maize hybrid breeding programs incorporating materials from various germplasm sources. This study was conducted with germplasm varying in their maize streak virus (MSV) reaction, genetic, and geographic origin. In a half diallel cross of six parents, general and specific combining abilities were determined for grain yield, days to silking, ear height and MSV disease resistance. The grain yields of the single crosses were significantly higher from those of the hybrid checks, H614 and H513, which are popular varieties. The importance of both GCA (53%) and SCA (47%) for grain yield was observed, but a preponderance of GCA existed for days to silking, ear height, and MSV disease resistance. The best general combiners for grain yield and MSV resistance were CML197 (0.92, p<0.001) and C92 (-0.61 p<0.001) respectively. The prediction of hybrid performance for grain yield and MSV resistance could be based on GCA alone, but this should be within specific niches since GCA interacted highly with environments. Key words: grain yield, MSV, GCA (general combining ability), SCA (specific combining ability), single crosses.