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.
