Hybrid Technology in Cruciferous Vegetables

Abstract

Use of male sterile plants has become an important technique in heterosis breeding,which simplify and reduce the cost of hybrid seed production. Cruciferous vegetables are very important crops in the world, and two types of male sterility have been mainly explored in cruciferous vegetables (1) nuclear male sterility, this kind of male sterility is controlled by the dominant or recessive nuclear genes, and its sterility is easy to be restored, but difficult to maintained; (2) cytoplasmic male sterility, in which male sterility is controlled by a particular cytoplasmic male sterile gene (S). Cytoplasmic male sterility is easy to be maintained but complicated to be recovered. Male sterility can be produced by different ways; natural mutation, wide hybridization, and protoplast fusion. Ogu CMS and Polma CMS were found in radish and B. napus respectively by natural mutations. Among the male sterile materials, most of them were obtained by the wide hybridization among varieties, species and genera. CMS cabbage was produced by the fusion of leaf protoplasts from fertile cabbage and CMS Ogura broccoli lines. The Pol CMS had been transferred from CMS B. napus to Chinese cabbage. Chinese breeders produced many cabbage varieties after introduced male sterility from other materials. A new cabbage hybrid varieties Zhonggan no.16, 17 and 18 were produced by hybridization of dominant genic male sterility line and inbred line in China. A stable CMS line of tuber mustard was developed by distant crosses and subsequent backcrosses and induced 100 % male sterility. To date, extensive efforts have been made on identification of male sterility systems and the possibilities of development of hybrids in application.