丛枝菌根真菌对羊草凋落物降解作用的研究

丛枝菌根真菌（Abuscular mycorrhizal fungi）能够影响植物生长及养分含量,从而影响凋落物的降解。采用根袋的方法研究了接种两种丛枝真菌Glomus mosseae和Glomus claroideum对羊草（Leymus chinensis）地上部及根系凋落物降解的影响。结果表明,随时间的延长,凋落物的重量逐渐减少,凋落物氮、磷含量均表现出先下降后逐渐升高的趋势。接种对地上部凋落物的养分含量及降解速度未产生显著性影响,但显著降低了根系氮磷含量及降解系数。接种Glomus mosseae和Glomus claroideum羊草根系氮、磷含量均显著低于CK;接种与未接种相比羊草根系k值显著降低;根系C：N未接种处理显著低于接种处理。说明丛枝菌根真菌可能间接影响草原生态系统中有机物质的分解和养分释放。

Role of arbuscular mycorrhzizal fungi in Leymus chinensis litter decomposition

The symbiosis with arbuscular mycorrhizal fungi is known to affect growth and tissue quality of plants.Therefore,my-corrhization may also have ＂afterlife＂ effects on decomposition dynamics.We designed an experiment using the litterbag technique to research role of arbuscular mycorrhzizal fungi Glomus mosseae（BEG167）and Glomus claroideum（BEG180）in Leymus chinensis litter decomposition.Litters embeded in soil were sampled after 4,7,14,21,35,56 days.Using the routine methods analysed residue remaining and N、P concentrations.Experiment shows：Shoot and root dry weight of mycorrhizal and non-mycorrhizal Leymus chinensis litters significantly reduced gradually over times.Shoot and root both N and P concentrations increased gradually over times.Root decomposition rate and N、P concentrations of mycorrhizal Leymus chinensis were lower than that of non-mycorrhizal control,but there were no significant difference in shoot.The result will provided the theoretical basis on the role of arbuscular my-corrhzizal fungi in Leymus chinensis litter decomposition.