南繁基地牛筋草对草甘膦的抗药性研究

Study of glyphosate-resistant Eleusine indica in seed breeding base in Hainan

牛筋草是一年生禾本科恶性杂草,在我国黄淮海流域及长江以南地区的农田危害严重。草甘膦是一种优良的非选择性除草剂,随着生物育种产业化的推进,草甘膦会逐步在玉米、大豆等作物田登记应用。育种基地抗草甘膦杂草的产生是其快速传播的潜在因素。为明确三亚一育种基地牛筋草种群对草甘膦的敏感性,本研究利用生物测定、分子生物学等方法检测了待测种群的抗性水平,并分析了可能的分子机制。结果发现,草甘膦对牛筋草种群的生长抑制中量为2053.0 g/hm^(2)(有效成分用量),抗性指数(RI)为5.0;靶标基因EPSPS的保守区域无突变,但相对表达量是敏感种群的47.4倍;抗性植株中EPSPS蛋白的浓度是敏感植株的17.1倍。以上结果表明,该牛筋草种群对草甘膦产生了中等水平抗性,靶标基因过量表达是其抗性机制之一。

Eleusine indica is an annual malignant Poaceae weeds.This grass inflicts substantial damage to farmlands in the Huang-Huai-Hai Region and south of the Yangtze River.Glyphosate,renowned for its efficacy as a non-selective herbicide,is gradually finding application in corn,soybean,and other crop fields with the advancement of biological breeding industrialization.The emergence of glyphosate-resistant weeds in seed breeding bases serves as a potential factor for their rapid spread.To clarify the susceptibility of E.indica to glyphosate in Sanya,Hainan province,whole-plant bioassays,target gene mutation,and expression detection were conducted to detect the resistance levels and mechanisms.The results showed that the GR 50 of this population was 2053.0 g/hm^(2),with a resistance index(RI)of 5.0.There was no significant difference in the conserved region of EPSPS between the resistant and susceptible populations.However,the relative expression level of the target gene EPSPS in the resistant population was 47.4 times of that in the susceptible population.In addition,the EPSPS protein concentration in resistant plants was 17.1 times of those in susceptible plants.These results suggest the evolution of glyphosate resistance within the population,with one of the resistance mechanisms involving an increase in target protein content due to EPSPS overexpression.