Seasonal dynamics in arbuscular mycorrhizal fungal colonization and spore numbers in the rhizosphere of Dactylis glomerata L. and Trifolium repens L.

摘要

The seasonal dynamics in the colonization of the rhizosphere of orchardgrass (Dactylis glomerata L.) and white clover(Trifolium repens L.) pastures by arbuscular mycorrhizal (AM) fungi and the production of spores in an artifical Japanesegrassland was investigated over 12 months (between December 2001 and December 2002). The results showed that the AMfungal colonization fluctuated seasonally in the rhizosphere of both pastures. The total AM fungal colonization of the twopastures decreased during winter, then increased from March to June as the pastures grew, but slightly decreased again inJuly and August, and again followed an increase in September. There was significant difference of the colonization byarbuscules and vesicles between the two pastures (p<0.05). Besides, the vesicular colonization of orchardgrass was higherthan that of white clover, but the opposite trend was observed for arbuscular colonization. Similarly, the numbers of AMfungal spores in the pastures varied throughout the year, decreasing from spring to summer, then slowly increasing in latesummer, reaching peak levels in winter. There is significant correlation between the frequency of spores in the rhizospheresoil and both soil temperature and pH.