小麦及变异后代对部分农田杂草的化感效应及其防控潜力

Allelopathic Effect of Wheat and Its Mutating Offsprings on Farmland Weeds and Their Control Potential

以外源DNA供体高粱、变异新品系89122和春小麦品种陇春13号为试验受体,3种杂草水浸提液为试验供体,通过正向和逆向化感抑制敏感性测试与评价,分析3种作物的遗传变异特性和化感潜力,评估小麦化感抑草潜力变异特性及遗传机制,为实现小麦抗杂草潜力的遗传改良提供理论支撑。结果表明,高粱DNA导入受体春小麦陇春13号后,其后代在农艺性状等方面发生变异,其对供试杂草的化感敏感性也发生变异;3种杂草水浸提液对3种供试作物种子萌发、幼苗形态特征和物种水平均有不同程度的抑制作用,且抑制作用随处理浓度的增大而增强,具有明显的浓度依赖性;灰绿藜除在种子萌发阶段对高粱的化感抑制作用较弱外,在其他作物幼苗生长阶段的化感抑制作用均明显强于稗和狗尾草,印证了灰绿藜在农田杂草群落中较强适应性主要表现在其对作物幼苗生长阶段的影响,而非种子萌发阶段。灰绿藜通过化感抑制作用实现自身竞争力提升,成为本区域的优势杂草,进一步拓宽了其生态位宽度,它在农田生态群落中的多维影响力强于稗和狗尾草。供试作物种子萌发阶段的敏感性要大于幼苗生长阶段,表现在其发芽指数的敏感性要大于萌发率,说明供试农田杂草通过降低种子发芽指数、延长发芽时间来发挥化感作用,这意味着推迟与其竞争的作物种子的萌发时间,降低竞争作物的种子萌发率,必然会提升该杂草在农田生态群落中的生态位宽度,进而达到提升杂草自身竞争力的目的,这也是杂草自身物种生态位及其生态位构建的重要手段。

The exogenous DNA donor Sorghum bicolor,the mutanting new line 89122 and the spring wheat variety Longchun 13 were used as the experimental receptors,and the aqueous extracts of three weeds were used as the experimental donors.Through the forward and reverse allelopathy inhibition sensitivity test and evaluation,the genetic variation characteristics and allelopathy potential of the three crops were analyzed,and the variation characteristics and genetic mechanism of wheat allelopathy inhibition potential were evaluated,so as to provide theoretical support for the genetic improvement of wheat weed resistance potential.The results showed that after the S.bicolor DNA was introduced into the recipient Longchun 13,its offsprings mutated in agronomic traits,and its allelopathy to the tested weeds also mutated.The aqueous extracts of the three weeds inhibiting the seed germination,seedling morphological characteristics and species level of the three tested crops to varying degrees all had different degrees of inhibition,and the inhibition increased with the increase of the treatment concentration,which was obviously concentration-dependent.In addition to weak allelopathic inhibition,it is significantly stronger than Echinochloa crusgalli and Setaria viridis at other crop seedling growth stages,which confirms that Chenopodium aureum has a stronger adaptability in farmland weed communities mainly due to its influence on the growth stage of crop seedlings,not the stage of seed germination.Through its allelopathic inhibitory effect,it can improve its own competitiveness and become the dominant weed in this region,which further broadens its niche width.Its multi-dimensional influence in farmland ecological communities is stronger than E.Crusgalli and S.viridis.The sensitivity of the test crop seeds at the germination stage is greater than that of the seedlings at the growth stage.The sensitivity of the germination index is greater than that of the germination rate.Playing allelopathic effect means delaying the germination time of competing crops and reducing the seed germination rate of competing crops will inevitably increase the niche breadth of the weeds in the farmland ecological community,thereby achieving the purpose of enhancing its own competitiveness.This is also an important means of constructing the niche of weeds and their niche.