连续单一除草剂应用情况下的转基因直播稻田杂草群落动态

【背景】转基因抗除草剂水稻种植将导致连年连续使用单一目标除草剂,势必会影响杂草群落结构的变化,但其变化规律至今还不十分明确。【方法】于2011~2013年,连续3年在直播种植抗草铵膦转基因Bar68-1水稻田中,使用灭生性除草剂草铵膦,持续观察期间杂草群落结构变化,并与常规选择性除草剂丙草胺—苄嘧磺隆（丙·苄）的应用情况进行对比,以揭示由于种植转基因抗除草剂水稻而使用单一除草剂对稻田杂草群落结构的影响。【结果】草铵膦和丙·苄连续使用后,杂草的物种丰富度和总杂草密度均逐年显著降低。随草铵膦使用年限增加,控草效果持续提高并达到优良水平,而常规选择性除草剂丙·苄的长期使用,致使多年生杂草双穗雀稗演替为群落的优势种,杂草密度呈逐年增加的趋势,导致生物多样性指数显著降低。【结论与意义】抗除草剂转基因水稻种植,在抗性杂草演化之前,不会因单一灭生性除草剂的应用而导致杂草群落迅速朝不良方向演替。长期的群落演替还需要进一步研究观察。

The weed community dynamics of direct seeding transgenic rice field under continuous single herbicide treatment

【Background】The planting of transgenic herbicide-resistant rice requires a continuous application of unique targeting herbicide. This may lead to a change in weed community. However,how the weed community changes over time is still poorly understood. 【Method】In this study,the weed community structure was surveyed continuously in glufosinate-resistant transgenic rice Bar68-1 direct seeding field from 2011 to 2013,and compared with the treatment of conventional selective herbicide Bensulfuronmethyl ＋ Pretilachlo（ BMP）. 【Result】The results showed that both weed species richness and total weed density decreased over the3 years after continuous glufosinate and BMP treatments. The control of weed increased continuously and maintain better level with the increase year of glufosinate treatment. However,under the long-term treatment of conventional selective herbicides BMP,the weed community changed to a dominat perennial weed Paspalum paspaloides. The total weed density tend to increase trend and species diversity decrease significantly over time. 【Conclusion and significance】It is suggested that cultivation of herbicide-resistant transgenic rice under continuously use of a single non-selective herbicide would not rapidly lead to increase in weed community due the evolution of herbicide resistant weeds. But long-term weed community succession still needs to be further studied.