Herbicide-tolerant transgenic pineapple (Ananas comosus) produced by microprojectile bombardment

Transformed plants of the commercially important Thai pineapple (Ananas com osus 'Phuket') were produced following microprojectile-mediated delivery of the plasmid AHC25, carrying the beta -glucuronidase (gus) reporter gene an d the bialaphos resistance (bar) gene for herbicide tolerance, into leaves of micropropagated shoots. Transformed plants were regenerated from bombard ed leaf bases on Murashige and Skoog-based mew.-m containing 0.5 mg l(-1) 2 ,4-dichlorophenoxyacetic acid, 2.0 mg l(-1) 6-benzylamino purine and 0.5 mg l(-1) phosphinothricin. Integration and expression of the bar gene in rege nerated plants was confirmed by Southern analysis and RT-PCR, respectively. Regenerated plants were assessed in vitro and under glasshouse conditions for their tolerance to the commercial herbicide Basta(TM), containing glufo sinate ammonium as the active component. Plants sprayed with Basta(TM) cont aining concentrations of glufosinate ammonium up to 1400 mg l(-1) remained healthy and retained their pigmentation. The generation of herbicide-tolera nt pineapple will facilitate more efficient weed control in this widely cul tivated tropical crop. (C) 2001 Annals of Botany Company.