الفهرس 
Introduction
Analysis of varianceOnly 14 pages are availabe for public view
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Abstract
Canola (Brassica napus, L.) is developed from rapeseed plants as an oil crop having seeds contain less than 2 % erucic acid in the oil and whose meal contain less than 30 micromoles per gram of glucosinolates. The main objectives of this investigation were: To estimate the mean performances of the ten parental lines and their 90 F1 hybrids including reciprocals, To determine the amounts of heterosis from both the midparents and the better parent, To study combining abilities as an indication of the nature of gene action, To estimate heritability in both broad (h2b %) and narrow (h2n %) senses and To determine phenotypic and genotypic correlation coefficients between all pairs of traits studied in this investigation for each of parents and hybrids. The results of the estimated amounts of heterosis over midparents (M.P.) indicated the presence of significant heterosis for vegetative traits, yield, yield component traits and oil percent. The amounts of heterosis ranged from 0.5 % to 39.4 % for 1000 S.W.gms and N.sil./pl., respectively. On the other hand, heterosis versus the better parent was insignificant for some traits and highly significant for others. It ranged from 14.9 % to 109 % for N.pr.br./pl. and H.f.br.cms., respectively. The results from this investigation suggested that heterosis is present in canola as it is present in other field crops. It appeared that nonadditive genetic variances were present and were more effective in the inheritance of most traits specially yield component traits. Therefore, selection to recover high yielding lines from the segregating generations of the superior F1 hybrids would require the application of the reciprocal recurrent selection method. The other approach would depend on the production of F1 hybrids on commercial scale. This approach would demand the utilization of workable C.M.S. method to make hybridization possible keeping in mind the choice of parental lines to be used as male or female parent due to the presence of effective and important maternal effects.