Gene effects and variances in three wheat crosses using the five parameters model [electronic resource].

Includes references.

Three experiments were carried out using three crosses among five parents, namely Pastor x Giza 168, line 2 x Gemmiza 9 and Pastor x Sids 1. Five populations (P₁, P₂, F₁, F₂ and F₃) for each cross were used in this investigation. Significant positive heterotic effects were obtained for most of the characters studied in the F₁ generations. However, significant negative heterotic effects were found for no. of kernels/spike in the three crosses; and for all other characters except for 100-kernel weight in the third one. Over dominance, towards the higher parent was detected for all characters except for no. of kernels/spike where the over dominance in the first and second crosses or the dominance effects were all towards the lower parent for all characters. Inbreeding depression estimates were found to be significant for all studied attributes except for kernels weight in the first cross, for no. of spikes/plant and kernels weight in the second cross and for no. of spikes/plant, no. of kernels/spike and grain yield/plant in the third one. On the other side inbreeding depression was significantly negative for kernels weight in the first and third crosses and for straw and biological yields/plant in the third one. F₂ deviation (E₁ was significant for all studied characters and for all crosses except for straw and biological yields/plant in the first cross, no. of spikes/plant and grain yield/plant in the second cross and for biological yield/plant in the third one. Moreover, F₃ deviation (E₂) was Significant for all studied characters and in all crosses except for grain yield/plant. The (additive - additive x dominance) gene effect was significant for all characters in all crosses except for kernel weight in the first cross and biological yield/plant in the third one.

Summary in Arabic.

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