Genetical Studies of Yield and its Components in Durum Wheat Under Heat Stress | ||||
| Assiut Journal of Agricultural Sciences | ||||
| Article 5, Volume 45, Issue 5, December 2014, Page 53-78 PDF (436.22 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ajas.2014.3522 | ||||
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| Abstract | ||||
| The present study was carried out at Assiut Agricultural Research Station during 2007/2008, 2008/2009, 2009/2010 seasons. Diallel cross without reciprocals among eight parents of durum wheat namely, Sohag 3 (P1), line #1 (P2), line# 2 (P3), Bin- Sweef 1 (P4), Bin- Sweef 5 (P5), Karifla (P6), Altar 84 (P7) and Admor (P8) were used to estimate heterosis, and general and specific combining ability under recommended and late planting dates. Mean squares showed that highly significant differences among genotypes, parents and crosses for all studied traits in the F1's and F2 generations, except number of spike/plant under late planting date. Moreover, both general (GCA) and specific (SCA) combining abilities were highly significant for most studied traits in the F1's and F2 generations under both planting dates except grain yield/plant, biological and number of kernel/spike in the F1's under late planting date in the SCA .The estimates of heterosis for grain yield/plant indicated that seven crosses out of 28 F1's hybrids significantly surpassed their better parent with percentage ranged from 8.798 (P4×P7) to 41.22% (P1×P6). These relatively high heterotic percentage along with the variability existed among all diallel set increase the chance of good recombination's that can be isolated in the following generations particularly, when selfing in the following generations gives an essentially homozygous state and enhances the role of selected plants in reducing the effects of dominance. However, the additive gene effect was of great importance in the performance of the most studied trait i.e. No. of spikes/plant, grain yield/plant (g), biological yield/plant (g), number kernel/spike. Moreover, the parents P 7 and P4 were good combiners for four traits i.e. Number of spikes/plant, grain yield/plant (g), biological yield/plant (g), number kernel/spike while, P2 was the best for only three traits i.e. days to heading, maturity and number kernel/spike date in the F1's and F2 generations. Meanwhile, significant SCA effects for grain yield were found in four out of the 28 F1's crosses P1×P4, P1×P6, P4×P7 and P6×P8 giving positive values of SCA effects under normal planting date and one cross P2× P4 under late planting date. On the other view, F2 populations, one crosses P3× P8 gave positive values of SCA effects .while in the F1'sand F2 generations, only one cross; P3×P8 gave positive values of SCA effects for 100- kernel weight under both planting date. | ||||
| Keywords | ||||
| diallel; crosses; durum wheat; Heterosis; combining ability (GCA & SCA) | ||||
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