الفهرس 
Introduction
Effect of medium composition on androgenesisOnly 14 pages are availabe for public view
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Abstract
The experiment was undertaken in vitro to study the effect of genotypes under three levels of 2,4D and their interaction on androgenic haploid production in Canola (Brassica napus), and for partition the genetic variance to it?s components using half diallel mating designs of five inbred lines. These lines were Serw 4, Serw 6, Pactol, Drakker and Fido. ?Tests of significance revealed that the genotype mean squares and the variation due to levels and genotype x levels interaction were highly significant with respect to in vitro traits. ?The greatest frequencies of responding anthers and green plantlet ratio were observed in Fido (P5). While, Serw 6 (P2) had the greatest frequency for embryoid induction and number of embryoid/responded anthers. In general, Pactol x Drakker (P3 x P4) was the best combination for responding anthers and number of embryoid/responded anthers. ? The results showed that the addition of 2 mg/l 2,4D to B5 nutrient medium and decreasing this concentration to 0.2 mg/l in regeneration medium could be the best concentration for anther culture purpose in rapeseed. ?The results of heterosis revealed that the cross Pactol x Drakker (P3 x P4) was the best combination for responding anthers and number of embryoid/responded anthers. ?GCA and SCA mean squares were highly significant in all studied in vitro traits except for SCA in the case of embryoid induction. ?Heritability in broad sense was larger than those in narrow sense for all in vitro traits, insuring again the major role of dominance genetic variance in the expression of these traits.