EMS处理甘蓝型油菜（Brassica napus）获得高油酸材料

【Objective】 To determine major fatty acid contents of progenies mutated by EMS, and analyze the high oleate mutant (05-4) obtained from M2 at molecular level. 【Method】 The rapeseed seeds were treated with EMS at there levels of 0.5%, 1.0% and 1.5%, respectively. The fatty acid contents were analyzed in M1 and M2 individual plants of mutagenic progenies. The FAD2 genes were cloned for the analysis of the nucleic and amino acid sequences. 【Result】 A high oleate plant was produced from M2 population of 1.5% EMS (oleate content 71%); The FAD2 gene sequences analysis indicated that A mutated into G at 614 bp from the start codon leading to the substitution of aspartic acid by glycine in FAD2A gene, the nucleic acid mutations at 59 bp and at 722 bp sites led to the substitution of asparagine by threonine and tyrosine by phenylalanine in FAD2B gene, respectively. 【Conclusion】 The oleate content can be influenced by using 1.5% of EMS to treat the rapeseed. The amino acid substitutions of mutant at residue sites 205 and 241 in FAD2A and FAD2B respectively all take place in the catalytic center of enzyme, these changes in structure result in the loss of the oleoyl-PC desaturase activity and increase the oleate content.