Genetic Variability and Heterosis in F1 and F2 Generations of Diallel Crosses among Seven Wheat Genotypes | ||||
| Journal of Plant Production | ||||
| Article 13, Volume 9, Issue 12, December 2018, Page 1075-1086 PDF (809.59 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jpp.2018.36631 | ||||
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| Authors | ||||
| A. A. El-Gammaal1; A. I. Yahya2 | ||||
| 1Department of Agronomy, Faculty of Agriculture, Tanta University, Egypt. | ||||
| 2Wheat Res. Dept., Field Crops Res. Institute, ARC, Egypt. | ||||
| Abstract | ||||
| In order to study the effect of heterosis and nature of genetic on plant height and yield traits were studied in a 7x7 diallel cross without reciprocals and their F2 generation in wheat to define and select an efficient and prospective material for immediate use in hybridization programs to improve grain yield of wheat in Egypt. Parents, F1 and F2 were evaluated for quantitative traits in 2016/2017 season. Significant genotype mean squares and its components (parents and crosses) were obtained for all traits in both generations. Significant heterosis in F1 generation was obtained for all studied traits. Heterosis of grain yield/plant relative to mid parent varied from 4.64 to 75.50% in F1 crosses. The P2xP3, P1xP4 and P2xP5 were the best crosses for grain yield heterosis. General (GCA) and specific (SCA) combining ability mean squares were significant for all traits. MS (GCA)/ MS (SCA) ratios indicated the relative importance of additive and non-additive gene action in their inheritance for all the traits. The nine crosses i.e. P1xP2, P1xP6, P2xP5, P2xP6, P4xP5, P4xP6, P5xP6 and P5xP7 had significant and positive effects in F1 and F2 generations and contained Inter-and intera-allelic interactions. Generally, no wide differences in the genetic parameters in F1 and F2 generations were detected. Highly significant and larger (in magnitude) values of dominance component (H2) than additive were obtained for all studied traits resulting in more values of (H1/D)0.5 which were more than unity in both generations. High heritability values (in a broad-sense) along with medium or low ones in narrow-sense were exhibited in both generations, indicating that most genetic variances were due to non-additive genetic effects. The regression line passed through the origin in spike length and No. of spikes/plant in F1 generation and 1000-grain weight in F2 generation, revealed a presence of complete dominance. Meanwhile, it intersects the Wr axis above the origin in plant height in both generations,1000-grain weight in F1, No of spike/plant and Spike length in F2, reflecting partial dominance. | ||||
| Keywords | ||||
| Wheat; diallel analysis; gene action; Combining ability | ||||
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