Since there are no (or few) formal Egyptian (registered) cultivars of turnip and white radish, So, this investigation was carried out for studying the coefficient of variation and genetic differences within and between nine native landraces of turnip and white radish, unregistered cultivars, which were collected from different regions (nine governorates) of Egypt as a first step towards registering them, if they were genetically pure or including them in breeding programs to improve and establish new cultivars. This investigation was carried out at a private farm in Arab Elsabha, Dar Elsalam, Sohag governorate, during the winter seasons of 2017/2018 and 2018/2019.
Results indicated that both turnip and radish Genotypes exhibited obvious differences among the native landraces of them for most of the studied characters. On the other hand, coefficients of variations (C.V.%) of the nine Balady landraces both of turnip and radish were less than 25 % for all the studied characters except a few exceptions. These results indicate that there were no significant differences within the nine Balady landraces for turnip and radish, separately. Consequently, these Balady landraces are largely genetically identical.
Mean squares of genotypes were found significant or highly significant for all characters except for both of No. of leaves/plant and weight of 1000 seeds regarding turnip and for the weight of 100 seeds concerning radish. With regard to the genotype × year component of variance, it was highly significant in only weight of 1000 seeds for turnip and it was insignificant for the studied traits of radish. The insignificance of this component showed that the selected genotypes succeeded to possess the same good performances in the two years of the test.
The partitioning of variance into its various components that a large portion of total variances of most studied traits, in all turnip and radish genotypes, would be attributed to genotypes. It should be mentioned here that genetic variance would be biased upward since it contains a non-partitioned genotypic × location source of variance; so, these results could be accepted under the designed conditions of this investigation and any wider implications warrant further research. The estimated broad-sense heritability of the various studied characters reflected high values (> 70%) in most studied traits of all turnip and radish genotypes These results gave information on the magnitude of genetic variation.