Die Bodenkultur - Journal for Land Management, Food and Environment

M.R. AHMADI:

Study of Genetic Variability of Resynthesized Rape Seed Forms

Summary

The genetic variability of 79 induced amphidiploid rape seed genotypes was investigated during two years under field and green house conditions. These lines were produced by artificial species hybridization between different forms of B. oleracea- and B. campestris and subsequent doubling of chromosomes of F1-generations by means of colchicines treatment. The resynthesized rape seed forms were compared with two improved varieties. With respect to the time of flowering and the amount of oil content the lines showed least variation. Regarding to cold tolerance, growth after winter, leaf surface, thickness of stalk and grain yield, variation was highest when compared with the improved varieties. The highest operative heritability was found for the time of flowering and the oil content, the lowest for pod bearing and leaf abscission. There was a significant difference among various genotypes with respect to all investigated characteristics. Pod bearing in self pollinated genotypes was greatly reduced compared to open pollinated plants of the same genotypes. This reduction in the seed set and pod bearing was for the most part due to the self incompatibility factor rather than genetic variability. The F1-hybrids investigated in this study can be used successfully in backcrossing with improved varieties for transferring the desirable traits such as high oil content and disease resistance. The genetic variation that exists among the artificially produced F1-hybrids can be useful for further improvement of the existing varieties.