GENETIC STUDIES ON GRAIN YIELD AND OTHER EARLINESS TRAITS IN THREE BREAD WHEAT CROSSES | ||
| Egyptian Journal of Agricultural Research | ||
| Article 15, Volume 85, Issue 2, July 2007, Pages 551-562 PDF (3.27 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejar.2007.214682 | ||
| Author | ||
| HAYAM S. MAHGOUB | ||
| National Wheat Program, Field Crops Research Institute, Agricultural Research Center, Giza, Egypt | ||
| Abstract | ||
| Genetic variance, gene action, heritability, and the predicted genetic gain from selection for earliness, grain yield and its components in bread wheat were estimated by using five parameters model. The field experiments were carried out at Sakha Agricultural Research Station from 2002/2003 to 2005/2006.Five populations (P1, P2, F1, F2, and F3) of the following three bread wheat crosses were used cross 1 :Sakha 61 x Sakha 93 (Early x Intermediate). cross 2 : Sakha 61 x Gemmiza 9 (Early x Late) and cross 3: Sakha 93 x Gemmiza 9 (Intermediate x Late). All studied characters showed significant genetic variance in the three crosses. Significant negative heterosis to earlier parent was detected for heading date in the first cross, and for the first and second crosses showed negative heterotic effect.for maturity dates. On the other hand, significant positive heterosis was found for most characters in the third cross, and for plant height, grain yield / plant, and kernel weight in the three crosses. Meanwhile, significant positive heterosis was found for number of kernels per spike in the first and third crosses. The potence ratio (P) indicated over dominance towards the higher parent for grain yield / plant, number of kernels / spike, and kernel weight in the first cross and for days to heading, and grain yield / plant in the second cross and for all characters in the third one. On the other side, over dominance for plant height and partial dominance for days to heading and maturity, and third crosses. The potence ratio (P) indicated over dominance towards the higher parent for grain yield / plant, number of kernels / spike, and kernel weight in the first cross and for days to heading, and grain yield / plant in the second cross and for all characters in the third one. On the other side, over dominance for plant height and partial dominance for days to heading and maturity, and number of spikes/plant, towards the lower parent were detected in the first cross and for number of kemels/ spike in the second one. In general, significant positive values were estimated for inbreeding depression in most studied characters. Meanwhile, these values were significant and negative for heading date, plant height, and number of spikes / plant, in the first cross. Moreover, high to moderate and moderate to low values of broad and narrow sense heritabilities, respectively were detected for all studied characters. The additive gene effect (d) was significantly positive for all studied characters except for plant height, and number of spikes / plant in the first cross, while it was significantly negative for heading and maturity date, plant height and number of kernels / spike in the first cross and for plant height in the second one. Dominance gene effect (h) was significant only for number of spikes / plant, and nurhber of kernels / spike in the first and second crosses and for heading and maturity date in the third and first cross, respectively Dominance X dominance gene effects were significant only for heading date and number of kernels / spike in the second cross. Similarly, additive X additive (i) gene effects were significant for heading date and grain yield / plant in the first and third crosses, number of spikes / plant in the first and second crosses and for number of kernels / spike in the second and third crosses, also, for maturity date and plant height in the second cross. | ||
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