Studies On Distant Hybridization Between Brassica Napus And Eruca Sativa

Bassica napus,a member of Cruciferae,is an amphidiploid specie originated from interspecific hybridization of B.rapa and B.oleracea.B.napus was first planted in Europe during 1930s,thereafter it was widely cultivated in China,India,Canada,Australia and some European countries and has now become the third largest economic crop around the world.Both the domestic cultivation and its origin history of B napus as allodidiploid are not so long,leading to the narrowness of its genetic background as well as weak resistance to adversity,pest and disease invasion,thus the yield of B.napus has no substantial breakthrough for a long time.Exploiting valuable characters from related species and transfering them into B.napus using modern biotechnology has been tried by many scientists.Eruca sativa Mill.in the Cruciferae family,grown in arid and semiarid lands,is an important oilseed crop with high resistance to drought,poor soil and diseases as well as other excellent features.In this study,some hybrids between B.napus and E.sativa were obtained by ovule culture.The hybrids were identifed by morphology,molecular markers and cytology.The main results are as that follows:1.33 putative hybrid plants were obtained through embryo rescue by using male sterile line P690 of B.napus as the female parent and five Eruca lines as male parent.2.There exsist severe reproductive barriers between B.napus and Eruca.Results indicated high crossing incompatibility between B.napus and Eruca and the ovary development of hybrids was low.The highest affinity of 0.0623 occurred between B.napus P690 and Eruca sativa cv.Hubu-13.3.One true hybrid BE1305 between B.napus and E.sativa was confirmed by SSR,ISSR molecular markers and cytologic method.The F1 somatic chromosome number was 2n=30.PCR products by primer SSR11 and ISSR2 in 2%agarose gel showed bands of both parents.Its mophology is more similar to the female parent.Purple stem,leaf and flower buds and deep leaf incisios were observed in the hybrid,which is characeristic of the male parent.The hybrid also showed relatively narrow petals and pale flower colour typical of Eruca sativa.