Investigating gene introgression from rape to wild turnip

Abstract

Gene introgression from crops to weedy relatives has become an important issue with the development and release of transgenic crops This study investigates hybridization between rape and a New Zealand population of wild turnip (Makarewa Southland) The rape used was a rapid cycling nontransgenic line homozygous for a single dominant mutation conferring resistance to the herbicide chlorsulfuron Seed from wild turnip plants were harvested following hand pollination in a greenhouse and after natural pollination in field trials that were conducted at two ratios of rapewild turnip 11 and 1400 Interspecific hybrids were identified in the progeny populations by in vitro screening of seedlings for resistance to chlorsulfuron Their hybrid status was confirmed by DNA content using flow cytometry As expected hand pollinations produced 100 hybrid progeny illustrating a high potential for interspecific hybridization between rape and wild turnip In contrast hybrids were very rare under natural field conditions