基于根系分泌物研究混合型邻群环境对小麦幼苗亲缘识别的调控作用

Effects of neighborhood complexity on the responses of wheat seedlings to root exudates-mediated kin recognition

采取根系分泌物替代邻居植物的方法,设置近缘(品种内)、种内远缘(品种间)和种间远缘(物种间)3个亲缘关系处理,单一和混合亲缘型两个水平邻群复杂性处理以及两个小麦(Triticum aestivum)品种处理的交互实验,探究混合型邻群环境对小麦幼苗在亲缘识别中形态性状表达的影响。结果表明:亲缘关系和邻群复杂性对小麦幼苗的比叶面积和比根长具有显著影响,它们的交互作用对比叶面积、总根长、比根长和根系平均直径亦具有显著影响;与单一型近缘及单一型种内(或种间)远缘邻群处理相比,混合型种内(或种间)远缘邻群中小麦的比叶面积等形态性状或是处于更高(或更低)水平,或是无显著差异;小麦对亲缘识别的响应存在品种差异性;混合亲缘型邻群中小麦响应亲缘识别的形态性状表达并不处于由单一型近缘邻群向单一型远缘邻群过渡的中间水平。

To investigate the responses of wheat seedlings to kin recognition in a complex neighborhood composed by both kin and stranger individuals,we conducted an experiment with hydroponically growing two wheat cultivars exposed to root exudates which varied with three levels of relatedness(i.e.intra-cultivar,inter-cultivar and inter-species),and two levels of neighborhood complexity(i.e.all individuals from either the same level of relatedness or a mixture with half of them from intra-cultivar and the other half from inter-cultivar/specific).The results showed that both relatedness and neighborhood complexity significantly affected specific leaf area(SLA)and specific root length(SRL)of wheat seedlings,and they interactively affected SLA,total root length,SRL,and mean root diameter.These morphological trait values in the kin-stranger-mixed neighborhood were either significantly higher/lower or unchanged,as compared to those in the pure kin neighborhood and pure stranger neighborhood.Furthermore,these kin recognition induced responses were cultivar-dependent.Our results suggest that the growth and competitive strategies of wheat in response to a relatedness-mixed neighborhood are not simply at the average status between pure kin and pure stranger neighborhoods.