Evidence of resistance gene markers parasexual recombination in Magnaporthe grisea

Abstract

A selectable marker gene conferring resistance to bialaphos (Bar) was introduced into rice blast isolate 95-8-36 and another conferring resistance to hygromycin (Hph) into isolate P32-1 of Magnaporthe grisea by Agrobacterium tumefaciens- mediated transformation (ATMT) to demonstrate exchange of DNA. Many of the transformants of 95-8-36 and P32-1 were mixed by grinding and cultured on oat agar media. Spores were collected with sterile water and inoculated in PSA selection medium with hygromycin and glufosinate in order to screen the recombinants. Some isolates were obtained from the medium and confirmed to have Bar and Hph genes by PCR technique, indicating that M. grisea made parasexual recombination under the artificial conditions. The recombinants could inherit the double resistance stably such that their growth rate and sporulation ability also resemble their original isolates. Key words: Parasexual recombination, Magnaporthe grisea, resistant gene mark,Agrobacterium tumefaciens-mediated transformation (ATMT).