ESTIMATION OF COMBINING ABILITY AND HETE~OSIS IN SOME MAIZE INBRED LINES FOR THE IMPORTANT TRAITS | ||||
| Journal of Plant Production | ||||
| Article 5, Volume 29, Issue 1, January 2004, Page 133-143 PDF (191 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jpp.2004.238470 | ||||
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| Authors | ||||
| M. M. Abd EI-Maksoud,1; A. M. EI-AdI1; Z. M. EI-Diasty1; A. A. Galal2; R. S. Hassanin2 | ||||
| 1Dept. of Genet., Fac. of Agric., Mansoura Univ., Mansoura. Egypt. | ||||
| 2Maize Section, Field Crop Institute, ARC, Giza, Egypt. | ||||
| Abstract | ||||
| The present investigation aimed to evaluate some maize inbred lines for their combining ability and its behavior over different environmental conditions with respect to the important traits. Therefore. possible combinations in a half diallel fashion were made among five inbred Jines. The parental lines and their crosses were evaluated in two years, 2001 and 2002 at Farm of S akha Agricultural Research S tation for t he following traits: days to 50% silking, plant height, ear height, no. of kernels/row, no. of rows/ear, ear length, ear diameter and grain yield per plant. The obtained results could be summarized in the following: The variances among genotypes and their partitions: inbreds, crosses and inbreds versus crosses were highly significantly different for all the studied traits in the two years and combined, indicating that the parental lines are different in their genetic constitutions. However, years and their interactions with genotypes and their partitions mean squares were significant for most of studied traits. Both general (GeA) and speCific (SeA) combining ability mean squares were highly Significant for all the studied traits in the two years and combined. indicating the contribution of additive and non-additive gene action in the genetic expression of these traits. Furthermore, the SCA mean squares were larger in magnitude than the corresponding values of GCA mean squares, which were verified by GCA/SCA ratio with values less than unity for all the studied traits except no. of rows/ear. This suggested the predominance of non-additive (dominance) genetic variance in the inheritance of the studied traits except for no. of rows/ear, which was mainly controlled by additive genetic variance. The inbred line L-7041 proved to be the best general combiner among the inbred lines in breeding toward developing early and increaSing of number of rows/ear. While, the inbred lines Sd-7 and Sd-34 were the best general combiners for producing high yielding genotypes. Nso, the results revealed that it is not necessary that parents having high general combining ability effects would also contribute to high SCA effects. Thus, the crosses (Gz-628 x l- 8084), (Sd-7 x L-7041) and (L-7041 x L-8084) were defined as superior combinations, which showed the highest SCA and heterotic effects in most of studied traits. In conclusion, iudging by heterotic values general and specrnc combining ability as well as genetic variance components, the production of corn hybrids is the best breeding program for the improvement of these traits. | ||||
| Keywords | ||||
| maize; combining ability; heterosis | ||||
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