Transgenic dry bean tolerant to the herbicide glufosinate ammonium

The bar gene from Streptomyces hygroscopicus (Jansen) Labeda & I-Nons encodes phosphinothricin acetyl transferase (PAT), which confers tolerance to the herbicide glufosinate ammonium. In Brazil, the productivity of Phaseolus vulgaris L. (dry bean) has been declining in some regions. One of most limiting factors is weed competition. This study was conducted to evaluate the possibility of obtaining transgenic bean plants resistant to glufosinate ammonium, which would facilitate weed control during the summer season. The biolistic process was used to insert this gene into dry bean, and the integration was confirmed by Southern blot analysis. Two transgenic events, PHV119 and PHV122 were tolerant to 500 g ha(-1) of glufosinate ammonium under green house conditions, with no visible symptoms and developmental growth comparable to nontransgenic P. vulgaris. Field evaluation carried out with the PHV119 event has shown that the plants tolerated up to 400 g GA ha(-1), with no visible symptoms. Inheritance studies showed that the transgenes segregated in a Mendelian fashion.