pH值对Gigaspora margarita孢子萌发、菌丝生长与聚磷酸盐含量的影响

土壤pH值是影响AM真菌的生理与生态过程的重要因子之一,本试验在培养基上接种Gigasporamargarita的孢子,研究了pH值分别为5.2、6.0和6.8时孢子萌发率、菌丝生长和菌丝中聚磷酸盐(polyP)的含量。结果表明,不同pH条件下的孢子萌发率没有明显差异,培养12d后的萌发率为70%左右;随着pH的升高,菌丝的长度逐渐增加,表明低pH对菌丝的生长有一定的抑制效应;培养12d后,孢子中polyP含量低于菌丝中polyP含量,pH6.0和pH6.8的条件下菌丝中polyP含量明显高于pH5.2的含量,表明低pH也能降低菌丝中的聚磷酸盐含量。认为低pH对菌丝生长和polyP含量的抑制可能是其限制AM真菌功能发挥的重要机制之一。

Influence of pH value on the spore germination, hyphal growth and polyphosphate content of Gigaspora margarita

Soil pH value is one of the important factors affecting the physiological and ecological processes of AM fungi. In the present experiment, spores of Gigaspora margarita were inoculated on media (at pH 5.2, 6.0 and 6.8, respectively), and the spore germination, hyphal growth and polyphosphate (polyP) content in both hyphae and spores, were investigated. Results showed that no obvious difference in spore germination was observed between different pH. Spore germination rate reached about 70% in 12 days after incubation. Hyphal length gradually increased with the rise in pH value, indicating an inhibitory effect of low pH on hyphal growth. In 12 days after incubation, polyP content in spores was lower than that in hyphae, and polyP content was clearly higher at pH 6.0 and 6.8 than pH 5.2, suggesting that low pH might decrease the polyP content in hyphae. It is suggested that the inhibition of hyphal growth and polyP content by low pH is one of important mechanisms responsible for the restriction on the functions of AM fungi.