Performance, combining ability and heterosis of canola (Brassica napus, l.) crosses grown under soil salinity conditions [electronic resource].

Includes references.

The present work was conducted on a half-dial lei set of crosses among 6 canola genotypes differed in salt or drought tolerance and seed yield. Field experiments were undertaken in salt affected soil Significant differences among parents and their hybrids were observed for all studied characters. P3 and P6 were of better performance than PI and P2followed by P3 and P". Eight crosses surpassed their corresponding better parent, in at least one character, due to their different parental genetic constitutions. The best two hybrids combined high seed yield and seed oil content(%) were PIxP6 and P4xP6 Both GCA and SCA effects were significant for all characters. GCA/SCA ratios indicated that additive component of variation predominated for number of branches and pods/plant, seed index, seed yield !plant and seed protein content(%), while non-additive was more important for plant height and first branch height. Seed oil content(%) seemed to be affected by both types of gene actions. Ps was the best general combiner , while P3 appeared to be the worst. Five crosses have shown positive and significant SCA effects for seed yield/plant . (P2XP4) hybrid was the best combination where it expressed significant SC4 values for almost all characters, P3 x P4 ranked as the second followed by P4 x P6 and then P2 x P5and PI x P5- The results revealed that seed oil content (%) behaved oppositely to seed protein content(%) , due to their negative association. Number of hybrids showing heterosis (relative to mid parents) and true heterosis (relative to better parents) were: one (plant height)! 6 (1s! branch height), 3(no. of branches), 6 (no. of pods), 3(seed index), 4(oil content), 4(protein content) and 12 for seed yield/plant. The highest yielding two hybrids were P3 x P" (103.05 and 52.57%) over their MP and Bp, respectively. The obtained results indicated that the crosses P3 x P" (for seed yield, its attributes and seed oil content), P" x P6 and PI x P6 (for both seed yield and oil content), P2 x P" (for seed yield without effect on oil content) and PI x P2, P2 X P3, P2 X P5 and P2 x P6 (for seed yield, its components and seed protein content) could be exploited, directly or indirectly according to their gene action nature.

Summary in Arabic.

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