丛枝菌根真菌对不同性别组合模式下青杨雌雄植株根系生长的影响

Effects of arbuscular mycorrhizal fungi on the root growth of male and female Populus cathayana individuals grown under different sexual combination patterns

丛枝菌根真菌(AMF)对雌雄异株植物根系生长,尤其是对邻近生长的不同雌雄个体的影响还鲜有研究。该研究以泥土:河沙:蛭石体积比为1:1:1的混合物为培养基质,分别在雄-雄、雌-雌和雄-雌3种组合栽培模式下对青杨(Populus cathayana)雌雄幼苗进行接种和不接种摩西球囊霉(Funneliformis mosseae)处理,通过比较接种AMF与否雌雄植株根系在侵染率、生物量、形态、碳、氮含量等方面的差异来分析AMF对青杨雌雄幼苗根系生长发育的影响。结果发现:与对照组相比,接种AMF对3种栽培模式下青杨雌雄植株的侵染率、根干质量、根系形态(除分枝强度、比表面积)和碳、氮含量影响显著。此外,不同性别组合模式对青杨雌雄植株的根干质量、根系形态和碳、氮含量影响显著。接种AMF后,与雌-雌合栽模式下的雌株相比,雄-雌合栽模式下雌株的根干质量、氮含量都有不同程度的提高,根系形态发生改变;而与雄-雄合栽模式下的雄株相比,雄-雌合栽模式下雄株的相应指标出现降低或轻微增加。该研究表明AMF对不同性别组合模式下青杨植株根系生长具有显著促进作用,尤其是雄-雌合栽模式下AMF接种最有利于雌株根系的生长发育。

Aims Accumulating evidence suggests that arbuscular mycorrhizal fungi(AMF)can promote the growth of plant roots.However,the effects of AMF on the root growth of dioecious plants,particularly those grown under different sexual combination patterns,remain largely unknown,this study therefore aimed at improving our understanding of the roles of AMF in these systems.Methods In the present study,homogenized soil(river sand:surface soil:vermiculite=1:1:1,volume ratio)was used as growth substrate.The Populus cathayana saplings uninoculated and inoculated with AMF under three sex combination patterns(male vs.male,MM;female vs.female,FF;male vs.female,MF)were defined as control(CK)and AMF treatment group,respectively.Subsequently,we compared the differences in colonization rate,root dry mass,root morphology,carbon(C)content and nitrogen(N)content between CK and AMF treatments under different sexual combination patterns.Important findings Our results indicated that colonization rate,root dry mass,root morphology(except root branching intensity,specific root surface area)and C,N content were remarkably altered upon inoculation with AMF in comparison to uninoculated controls.Furthermore,the sexual combination patterns were shown to significantly affect root dry mass,root morphology and C,N content of male and female P.cathayana.After inoculation with AMF,root dry mass,root morphology and N content of female individuals were increased whereas these parameters of males were decreased or slightly increased in inter-sexual groups compared with the respective intra-sexual groups.Collectively,our data demonstrate the growth-promoting effects of AMF on the roots of P.cathayana individuals grown under different sexual combination patterns,and such beneficial effects are most pronounced in females grown under inter-sexual combination patterns.