传粉导致的转基因白菜与其近缘种属材料间的基因流动

从形态、染色体及分子水平上证实，转基因不结球白菜(Brassica campestris ssp．chinensis var．utilis Tsen et Lee)中编码除草剂Basta抗性的bar基因能在田间条件下，经自然传粉，以较高频率侵入芜菁(B．campestris ssp．rapifera)、结球白菜(B．campestris／sssp．pek／nens／s)和不结球白菜(B．campestrs ssp．ch／nens／s)的基因组中，也能少量侵入同属异种的甘蓝型油菜(B.napus)基因组中；在温室人工辅助授粉条件下，除在上述种中的基因漂移率提高外，bar基因尚能以一定频率侵入同属的黑芥(B．nigra)、埃塞俄比亚芥(B．car／nata)、芥菜(B．juncea)基因组中，但始终未能得到转基因白菜与结球甘蓝(B．oleracea)、萝卜(尺．sativus)的杂种。转基因白菜与十字花科的7种常见杂草经温室人工辅助授粉，也均未得到抗性杂种。

Gene Flow from Transgenic Chinese Cabbage (Brassica campestris ssp. chinensis var.utilis) to Related Cruciferae Species Through Outcrossing

It was substantiated by morphological observation, chromosome and DNA identification that the bar gene, conferring the resistance to herbicide basta in transgenic Chinese cabbage ( Brassica campestris ssp. chinensis var. utilis Tsen et Lee), could intrude into the genomes of turnip ( B. campestris ssp. rapifera ), heading Chinese cabbage ( B. campestris ssp. pekinensis ) and other non_heading Chinese cabbage ( B. campestris ssp. chinensis ) in a relatively high frequency while into genome of B. napus at a low frequency via natural cross_pollination in open field. Herbicide resistant hybrids of B. nigra , B. carinata , and B. juncea could be obtained at certain frequency in the greenhouse by hand pollination. At no time did the resistant hybrid plants of transgenic Chinese cabbage with B. oleracea , R. sativus and seven wild weeds, widespread in China, gained in our experiments.