الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Cucumber is an important vegetable crop in the world. In Egypt, so far has been the production of trading hybrids, which led to import hybrids with high costs. The initiation of pure lines is the first step in genetic improvement of vegetables. One of the most successful methods is anther culture techniques which speed up the production of haploid plants for breeding programs. The present investigation was planned to determine factors affecting anther culture response in cucumber especially growth hormone concentrations, in order to present the best tool for increasing the frequency of haploids through anther culture technique. Six cucumber cultivars were used for anther culture purpose. Two media composition were used in this study; B5 medium with two hormone balances and MS medium with three hormone balances for induction and regeneration purpose. The recorded data on responding anthers, calli and green point percentages in vitro traits were subjected to statistical procedures. Mean squares of B5 and MS media indicated the presence of significant differences between genotypes for the studied traits with respect to different levels of hormone balance. This finding indicated that these genotypes are varied in their response to anther culture technique and the planned comparisons between these genotypes as well as the further partition of phenotypic variance to its components are valid. The hormone balance levels as well as genotype × levels interaction mean squares were highly significant for the studied traits on B5 and MS media. This indicates that these genotypes gave different response at different hormone balance on B5 and MS media. ‘Poinsett 76’ and ‘Algy’ were the superior varieties in most of cases with respect to the two hormone balance on B5 medium, while the variety ‘Speed Way’ was the best for all studied in vitro traits with respect to three hormone balance on MS medium. The best hormone balance for B5 medium with respect to cucumber anther culture purpose is B5 medium supplemented by 0.02 gm/l BAP. The results revealed that the genotypic variance was positive and larger in magnitude than environmental variance in the case of B5 medium for all studied traits. This finding indicated to the major role of genetic factors in the phenotypic expression of the studied traits. The results of combined data revealed that genotypic by hormone balances interaction (σ²g×m) was positive and higher than other components for the three studied traits. This finding may explain the different magnitude with different hormone balances. In conclusion, from the results it could be recommended that each cucumber genotype or group of genotypes need altered media for improvement their ability for haploid induction through anther culture technique.