In this study five varieties were used. These varieties were Suvin (P1), TNB (P2), Pima S6 (P3), G. 88 (P4) and G. 89 (P5). The all possible crosses among the three parental varieties to form 30 three way crosses. All genetic materials (five parental varieties, 30 three-way crosses, 10 F1 single crosses and two check varieties) were evaluated at Sakha Agriculture Research Station. Heterosis (Superiority) at Mid-parents, better parent, mid-F1 single crosses, better F1 single crosses, mid-checks and better check were evaluated for yield, yield components and fiber traits.
The results of the analysis of variances of all genotypes showed highly significant differences for all the studied traits.
For superiority (heterosis) over the mid-parents the results indicated that the three-way cross (G. 88 x G. 89) x Pima S6 cleaned the highest positive heterosis for boll weight (B.W) and number of seeds per boll (No.S./B.). The cross (Pima S6 x G. 88) x Suvin for seed cotton yield per plant (S.C.Y./P.) and number of bolls per plant No.B./P. In the same time the cross (G. 88 x G. 89) x TNB was the superior and had the highest heterosis for lint cotton yield per plant (L.C.Y./P.). On the other hand, the superior cross for lint percentage (L. %), lint index (L.I) and fiber strength (F.S.) was (Suvin x G. 89) x Pima S6. However, for 2.5% span length (2.5% S.L.), 50% span length (50% S.L.) and uniformity ratio % (U.R.%) the three way cross (TNB x Pima S6) x G. 89 was the superior and had the highest positive heterosis values (desirable).
Concerning heterosis over the better parent, the results cleared that the crosses (G. 88 x G. 89) x TNB, (Suvin x G. 89) x Pima S6 and (G. 88 x G. 89) x Pima S6 were the superior and had the highest positive heterosis values (superiority) for lint cotton yield per plant (L.C.Y./P.), lint percentage (L. %) and number of seeds per boll (No. S./B.). In the same time, the three way cross (TNB x Pima S6) x G. 89 was the highest for 2.5% span length (2.5% S.L.), 50% span length (50% S.L.) and uniformity ratio % (U.R.%). On the other hand, for seed index (S.I.) and boll weight (B.W.) the results cleared that the superior cross was (Pima S6 x G. 89) x TNB and the cross (Pima S6 x G. 88) x Suvin was the superior for seed cotton yield per plant S.C.Y./P. and number of bolls per plant (No.B./P.). However, the cross (Suvin x TNB) x G. 89 was the superior and had the highest positive heterosis values for lint index (L.I.).
The estimates of heterosis (Superiority) over the mid-F1 single cross. The results revealed that, the three way crosses (Pima S6 x G. 89) x TNB, (TNB x Pima S6) x Suvin, (G. 88 x G. 89) x Pima S6 and (TNB x Pima S6) x G. 88 were the superior and had the highest positive significant heterosis (superiority) for boll weight (B.W.), seed index (S.I.), number of seeds per boll (No.S/B.) and fiber strength (F.S.). While, the cross (Suvin x TNB) x Pima S6 was the superior and had the lowest negative heterosis value (desirable) for fiber fineness. On the other hand, the cross (TNB x Pima S6) x G. 89 was the superior three-way cross for 2.5% span length (2.5% S.L.), 50% span length (50% S.L.) and uniformity ratio % (U.R.%). In the same time, the cross (Pima S6 x G. 88) x Suvin was the superior for seed cotton yield per plant and number of bolls per plant. While, the cross (G. 88 x G. 89) x TNB was the superior for lint cotton yield per plant (L.C.Y./P.) and lint percentage (L.%). Although, for lint index
Yehia, W.M.B. et al.
5924
(L.I) the cross (Suvin x TNB) x G. 89 was the superior and had the highest mean of superiority.
For heterosis over the better F1 single crosses, the results cleared that the cross (Pima S6 x G. 88) x Suvin was the superior for seed cotton yield per plant (S.C.Y./P.) and number of bolls per plant (No.B./P.). In the same time, the cross (TNB x Pima S6) x G. 89 was the highest for 2.5% and 50% span length, while, for lint cotton yield per plant and seed index the crosses (G. 88 x G. 89) x TNP and (TNB x Pima S6) x Suvin had the highest positive heterosis (superiority), respectively.
For heterosis over mid-checks, the results cleared that the three way crosses [(Pima S6 x G. 89) x TNB, (Pima S6 x G. 88) x Suvin, (G. 88 x G. 89) x TNB, (TNB x Pima S6) x Suvin, (TNB x G. 89) x G. 88, (G. 88 x G. 89) x Pima S6 and (TNB x Pima S6) x G. 88] were the superior crosses and had the highest positive heterosis values for boll weight (B.W), seed cotton yield per plant (S.C.Y./P), lint percentage (L.%), seed index (S.I.), lint index (L.I.), number of seeds per boll No.S./B. and fiber strength (F.S.), respectively. While, the cross (TNB x Pima S6) x G. 89 was the superior for 2.5% and 50% span length, as well as uniformity ratio %.
For heterosis (superiority) over the better check the results cleared that, the crosses (Pima S6 x G. 89) x TNB, (Pima S6 x G. 88) x Suvin, (TNB x Pima S6) x Suvin and (G. 88 x G. 89) x Pima S6 were the highest crosses and had the highest positive heterosis for boll weight (B.W.), seed cotton yield per plant (S.C.Y/P.), seed index (S.I.) and number of seeds per boll (No.S./B.), respectively. While, the cross (Suvin x TNB) x G. 89 was the superior for lint index (L.I.) as well as, for 2.5% and 50% span length the cross (TNB x Pima S6) x G. 89 was the superior and had the highest positive heterosis values (superiority).