宿主植物栽培密度对AM真菌生长发育的影响

THE EFFECTS OF CULTIVATED DENSITIES OF HOST PLANT ON THE DEVELOPMENT OF ARBUSCULAR MYCORRHIZAL FUNGI

温室盆栽条件下宿主植物高粱(Sorghum vulgare Pers.)的栽培密度对丛枝菌根(Arbuscular mycorrhizae, AM)真菌Glomus mosseae (Nicol.& Gerd.)Gerdemann & Trappe 生长发育的影响试验结果表明: 60株/盆密度处理的根外菌丝量及孢子数均高于其它处理.在一定栽培密度下(20～60株/盆),植株根系可溶性糖浓度与根外菌丝量呈显著负相关,与菌根侵染率呈显著正相关.植株根中磷浓度与根外菌丝量、根外菌丝量与孢子数均呈显著正相关.植株根中磷浓度与菌根侵染率呈显著负相关.结果说明:适当密植虽对植株生长有一定影响,但却促进了真菌的生长,此时菌根共生体有可能由互惠共生开始向偏利共生或弱寄生转化.密植作为一种调控手段,在菌剂生产中能获得较大数量的侵染根段、菌丝及孢子等繁殖体.

The effects of host plant(Sorghum vulgare)cultivated densities on the growth of arbuscular mycorrhizal fungus Glomus mosseae were studied. The results revealed that under the treatment of 60 plants/10L the fungus produced higher quantity of spores and external hyphae as compared with other treatments. In the range of 20 plants/10L to 60 plants/10L,the concentration of soluble sugar in roots was significantly and negatively correlated to the length of external hyphae in substrate, and significantly and positively correlated to root colonization. The concentration of P in roots was significantly and positively correlated to the length of external hyphae .The length of external hyphae in substrate was significantly and positively correlated to spore quantity in the substrate. It suggests that increasing the density of host plant properly could enhance the development of AM fungi, although plant growth was somewhat inhabited. Under the condition, the mutualism may start changing to commensalism or weak parasitism. The conclusion is that increasing the density of host plant might be a method of regulation to enhance the development of AM fungi to obtain more colonized roots, external hyphae and spores.