Effect Of Arbuscular Mycorrhizal Fungi On Ecological Adaptability Of Switchgrass

Panicum virgatum, commonly known as switchgrass, is a perennial warm season bunchgrass native to North America. It is studied and promoted as a model of energy plants from 1990. Introducing of switchgrass will richenour energy plant resources and help the development and use of renewable energy. In the present study, we chose two cytotypes of switchgrass, i.e. the lowland cultivars(Alamo, Kanlow) and three upland cultivars(Blackwell, Summer, Cave-in-Rock), and conducted field and pot experiment to learn the ecological adaptability of switchgrass in the low-latitude(Station of Guangxi Animal Science Institude, SGX) and mid-latitude regions(Zhuozhou Experimental Station, SZZ) of China, and the influence of soil microbes especially arbuscular mycorrhizal fungi to the growth and product quality of switchgrass. The main results are as below.Different ecotype of switchgrass showed obvious mycorrhizal colonization both in the low and high latitude regions, and the lowland cultivars produced higher AMF colonization level than the upland cultivars. In the field experiment of Guangxi, both the above ground biomass and yield of lowland cultivars were far more than the upland cultivars. But in Hebei experiment, the difference is not significant. For the upland cultivars, the content of hemicellulose, cellulose and lignin in the shoot were higher in Hebei than Guangxi. For the lowland cultivars, the hemicelluloses content hadlittle difference between the two regions, while the cellulose content was higher in low latitude, and the cellulose was lower in low latitude. These show the growth and quality are relatively better when switchgrass grow in its original latitude.The biomass, yield and phosphorus uptake of switchgrass were slightly lower in the benomyl treatments than the control, showing that arbuscular mycorrhizal fungi can promote the growth and development of switchgrass. The cellulose, hemicellulose and lignin content have no obvious difference either adding benomyl or not, which indicates arbuscular mycorrhizal fungi has no significant impact on the quality of switchgrass.Under greenhouse conditions, the biomass of switchgrass is significantly lower which grow in sterilization soil, revealing that the soil microbial have negative effect on the growth of switchgrass.