The Screening For Glyphsate-resistance Peanut(arachis Hypogaea L.) Germplasm And Preliminary Study On It’s Resistance Mechanism

Production reduction of peanut generally is 5 to 10% due to the weeds. The yield of peanut reduced up to15-20% or even more in serious weed plots. Therefore, the breeding of herbicide-resistant peanut varieties(lines) is distinct. In this study, 452 peanut(Arachis hypogaea L.) genetic resources were used for glyphosate(glyphosate) resistance screening in greenhouse, and the degree of resistance and the genetic stability of different peanut germplasm were further studied. Meanwhile, physiological and biochemical indexes of peanut under glyphosate stress were analyzed, combining with the expression analysis of EPSPS target gene by fluorescent Real-time quantitative PCR method in resistant susceptible varieties, to further clarify the resistance mechanism. The main results were as follows:1. 452 genetic resources of peanut(Arachis hypogaea L.) were used for 1.0 kg a.i·hm-2 glyphosate(glyphosate) resistance screening. The result showed that different peanut materials resistant to glyphosate had distinct differences. By subculture verification, high tolerance to glyphosate material C091 was screened out, which the overall resistance level was stabilization.2. After treatment under glyphosate, shikimic acid accumulation of sensitive material C179 reached 45.47 μg·g-1 and shikimic acid accumulation of resitant material C091 was 30.93 μg·g-1. Chlorophyll a and b of C179 were 0.72 mg·g-1 and 0.20 mg·g-1 respectively and that of C091 were 2.32 mg·g-1 and 0.99 mg·g-1 respectively. Soluble sugar content of C197 was 10. 85 mg.g-1 and that of C091 was 4.82 mg·g-1.3. Under the stress, POD and MDA content of levels of sentive material C179 were up to 22.55 μmol·g-1 and 0.007 U·g-1· min-1 respectively, which were 2.5 and 1.9 times of the control. The effection on resitant material C091 under stress was lighter. The POD and MDA content of C091 were 10.91 μmol·g-1 and 0.003 U·g-1·min-1 respectively.4. Analysis of EPSPS expression patterns in two materials C091 and C179 by Real-time quantitative PCR. The results showed EPSPS gene expression in C091 compared to C179 increased by about 2-fold.The test screened glyphosate-resistant peanut genetic resources under the natural condition, which can provide material for future cultivation of glyphosate-resistant peanut.