Combining ability studies on resistance to pink stem borer (Sesamia cretica) in new yellow maize (Zea mays) hybrids

Abstract

Maize (Zea mays L.) is the third most important staple crop in Egypt. Sesamia cretica (S. cretica), the most prevalent corn borer in Egypt attacks young maize plants after emergence, causing death of these plants (dead hearts) and its capable of damaging older plants causing drastic yield losses. This study was carried out at the Experimental Research Station of Moshtohor, Benha University, Al-Qalyubiyah Governorate, Egypt during the two successive seasons 2014 and 2015. A half diallel cross between nine yellow inbred lines of maize (Zea mays L.) was evaluated in under two environments i.e. (under borer artificial infestation conditions and normal conditions) in RCBD with three replications to estimate the combing ability and the interaction of hybrids under the artificial infestation. Artificial infestation was done by newly hatched larvae of the pink stem borer S. cretica. Highly significant crosses mean squares were detected for all the studied traits indicating the wide diversity between the parental materials used in this study. General and specific combining ability (GCA and SCA) were significant for all the studied traits except SCA for days to 50% tasselling and ear height at the infestation condition. The parental inbred line P6 and P9 were considered as good combiners for grain yield under infestation and non-infestation conditions as well as the combined over them. Six crosses i.e. (P1×P6, P1×P7, P2×P4, P3×P5, P5×P7, and P8×P9) exhibited positive significant SCA effects (favourable). Therefore, they could be utilized for future breeding work as well as for direct release after confirming the stability of their performances across different environments.

Keywords

• zea mays
• sesamia cretica
• borer
• combining ability