冀东野生大豆对草甘膦的耐性鉴定及耐性机制初步研究

为筛选耐草甘膦野生大豆种质并了解其耐性机制,本试验对采集于冀东地区的862份野生大豆进行了草甘膦的耐性鉴定。在草甘膦处理后,测定了高耐和敏感材料的莽草酸、丙二醛和叶绿素含量,过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性,以及草甘膦相关基因EPSPS表达量。结果显示,喷施草甘膦后,862份野生大豆材料中,药害等级在4级以上的材料占82.84%,3级占9.51%,2级占4.87%,1级占2.78%。筛选到高耐草甘膦的野生大豆材料Yong-33,其在1.125 kg a.i·hm^-2 草甘膦处理后植株存活率达到96.67%。经草甘膦处理后,与对照相比,高耐材料的叶绿素、丙二醛和莽草酸含量在检测的各时间点均无显著差异,敏感材料叶绿素含量显著降低,丙二醛和莽草酸含量显著升高;高耐材料POD、CAT和SOD活性以及EPSPS基因表达量均显著升高,而敏感材料酶活性及EPSPS基因表达量无显著差异。以上结果表明,野生大豆中存在高耐草甘膦的种质资源,在草甘膦处理后其植株内活性氧清除酶系活性升高,EPSPE基因上调表达,推测这是野生大豆对草甘膦耐性较好的原因。本研究筛选到的耐草甘膦野生大豆材料可为培育耐草甘膦栽培大豆新品种提供种质资源。

Identification of Glyphosate-Resistance and Preliminary Research on the Resistant Mechanism of Wild Soybean in Eastern Hebei Province

In order to screen germplasm resistant to glyphosate and study the tolerance mechanism of wild soybean, we identified the glyphosate-resistance of 862 wild soybean collected from the eastern of Hebei province, and the contents of shikimic acid, malondialdehyde (MDA) and chlorophyll, the activities of peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) and the expression of EPSPS gene in high-resistant and sensitive wild soybean materials were determined with glyphosate treatment. The results showed that under glyphosate treatment, the phytotoxicity grades of 82.83% wild soybean materials were 4 and 5, 9.51% materials were 3, 4.87% materials were 2, 2.87% materials were 1. The wild soybean yong-33 was high-resistance to glyphosate, the plants survival rate reached 96.67% after treated with 1.125 kg a.i·hm^-2 glyphosate. After glyphosate treatment, compared with the control, the contents of chlorophyll, MDA and shikimic acid in high-resistant material had no significant difference at each time point, the chlorophyll contents in sensitive materials were significantly lower, while the MDA and shikimic acid contents were significantly higher. The activities of POD, CAT and SOD and the expression of EPSPS gene in high-resistant material were significantly higher, but there were no significant difference in the enzyme activities and the expression of EPSPS gene in sensitive materials. These results suggest that there are high glyphosate-resistant germplasm resources in wild soybean. After glyphosate treatment, the increased expression of EPSPS gene may compensate the inhibition of EPSPS enzyme activity, which maybe explain for the high-resistance to glyphosate of the wild soybean. The glyphosate resistant wild soybean materials can provide germplasm resources for cultivating glyphosate-resistance cultivated soybean varieties.