1株抗草甘膦棉花突变体草甘膦抗性的初步鉴定

Preliminary Identification of Glyphosate Resistance of a New Cotton Mutant

目的在于探明1株新的草甘膦抗性棉花突变体是否能用于发掘新的草甘膦抗性基因以及在农业生产中作为抗草甘膦种质的选育和利用的潜在价值。本文采用PCR的方法,在基因组和转录水平上排除了CP4-EPSPS基因对该突变棉株的污染;通过测定莽草酸含量,鉴定了该突变体草甘膦抗性的典型生理特征;通过盆栽试验研究了该突变体苗期对草甘膦抗性的表型。结果显示:不论草甘膦处理与否,突变棉株莽草酸的含量都没有显著的积累,在生理水平上显示出草甘膦抗性植株的显著特点;2叶期时草甘膦处理结果显示,突变棉株的草甘膦抗性表型同孟山都的品种对草甘膦的抗性表型基本一致。在基因组和转录水平的PCR检测结果都排除了突变棉株草甘膦抗性的获得是CP4-EPSPS基因污染造成的。结合对其他已报道的草甘膦抗性基因的类似排除,说明该抗性突变存在着自身特有的分子机理。

The purpose of this paper was to identify the potential value of a novel glyphosate-resistant cotton mutant comprising a new glyphosate resistance gene and to evaluate its agricultural production as glyphosate-resistant germplasm for breeding and u- tilization. At genomic and transcriptional levels, polymerase chain reaction （PCR） assay was used to exclude possible contami- nation by theCP4-EPSPS gene in this mutant cotton. The relative content of shikimic acid was determined to evaluate the typical physical characteristics of glyphosate resistance of this mutant. The phenotype of this cotton mutant under glyphosate treatment was observed at the seedling stage in pot cultures. No significant accumulation of shikimic acid was detected with different con- centration or without glyphosate treatment in the mutant treated leaves, which indicated the typical physical characteristic of glyphosate resistance. The glyphosate-resistant phenotype of this cotton mutant was consistent with glyphosate-resistant cotton of Monsanto at the two-leave stage during glyphosate treatment. PCR showed that the CP4-EPSPS gene was not present in the genomic DNA or RNA of this mutant; thus, the glyphosate resistance of this mutant was not caused by the CP4-EPSPS gene. The results of similar exclusion tests for other reported glyphosate-resistant genes, indicated a new molecular mechanism existed in this mutant cotton.