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期 刊 ：植物保护学报 2011年

关键词：田旋花；草甘膦；耐药性；5-烯醇丙酮莽草酸-3-磷酸合成酶；

Keywords:Convolvulus arvensis, Calystegia hederacea, glyphosate, herbicide-resistant, 5-enolpyruvylshikimate-3-phosphate synthase,

摘 要 ：在温室条件下,测定了草甘膦对田旋花与打碗花生长的抑制作用及其体内莽草酸含量变化的影响,比较了两者5-烯醇丙酮莽草酸-3-磷酸合成酶(5-enolpyruvylshikimate-3-phosphate synthase, EPSPS)基因及编码氨基酸的差异,以探讨田旋花对草甘膦的耐药性机制.结果表明,田旋花 对草甘膦的耐药性较高, GR₅₀值(有效成分)为2 834.04 g/hm²; 打碗花相对敏感, GR₅₀值为210.63 g/hm².经有效成分922.50 g/hm²草甘膦处理后,耐药性高的田旋花体内莽草酸积累缓慢,处理后7天达到峰值,为397.69 μg/g;而打碗花体内莽草酸含量呈现持续快速升高的趋势,处理后13天达到峰值, 为1 299.52 μg/g.克隆获得的田旋花和打碗花编码EPSPS cDNA长度相同, 均为1 707 bp,编码520个氨基酸,两者在EPSPS保守区内存在不同的氨基酸位点,田旋花的第101位为极性丝氨酸,而打碗花为非极性苯丙氨酸.

Abstract:In order to demonstrate the mechanism of field bindweed tolerant to glyphosate, the effects of glyphosate on growth and shikimic acid accumulation of field bindweed Convolvulus arvensis and Japanese bindweed Calystegia hederacea were studied in greenhouse. And the EPSPS and encoded amino sequence of two weeds were compared. The results of bioassay and shikimic acid assay showed that the tolerance of field bindweed to glyphosate was significantly higher than that of Japanese bindweed, the GR₅₀ values were 2 834.04 g/hm² and 210.63 g/hm²(ai). The shikimic acid accumulation of field bindweed rose slowly and reached the peak value (397.69 μg/g) 7 days after treatment; whereas that of Japanese bindweed increased rapidly and continuously and reached the peak value (1 299.52 μg/g) 13 days after treatment. The full length of cDNA in EPSPS measured from field bindweed and Japanese bindweed were both 1 707 bp, encoding 520 amino acids. Sequence analysis showed that, different amino acid sites existed in two conserved region of both field bindweed and Japanese bindweed. The 101 amino acid in field bindweeds was polar serine, whereas the same site in Japanese bindweed was non-polar phenylalanine.

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