Diversity Of Arbuscular Mycorrhizal Fungi In Rhizosphere Soil Of Taxus Chinensis Var. Mairei And The Inoculation Effects Of PSB And AMF On Host Plant

To determine the diversity of arbuscular mycorrhizal fungi(AMF)in the rhizosphere soil of Taxus chinensis var.mairei and the inoculation effect of PSB(Phosphate solubilizing bacteria)and AMF on host plant.In China,we selected and sampled 12 different sampleplots to collect soil samples from July-September 2015.The relationship among the diversity of AMF,soil physical and chemical properties and the diversity of rhizosphere microorganisms community was analyzed by morphological method,molecular,biology method and DGGE,etc.And in order to make certain the effects of inoculations in the seedlings of Taxus chinensis var.mairei at the micro-ecological level,the number of culturable microorganisms,the enzyme activity and the soil microbial functional diversity of rhizosphere soil were studied,after inoculated with Sinorhizobium meliloti CHW10B(PSB)and/or Glomus constrictum(AMF).This study will provide theoretical guidance for the cultivation of Taxus chinensis var.Mairei and its efficient compound microbial fertilizer.The main results are as follows:1.A total of 36 species of AMF belonging to three genera were identified according to the morphological characteristics of the spores isolated from soil samples: A.tuberculata,G.deserticola,G.multiforum,A.scrobiculata,A.rugosa,S.nigra,G.constrictum,A.rehmii,A.laevis,G.multicaule,G.coremioides,G.lamellosum,A.cavernata,G.melanosporum,A.gerdemannii,G.convolutum,G.reticulatum,A.excavata,G.clarum,G.dolichosporum,A.colossica,A.morrowae,A.foveata,S.calospora,G.caledonium,G.coronatum,A.lacunosa,S.fulgida,G.etunicatum,A.bireticulata,G.aggregatum,G.mosseae,G.pansihalos,G.taiwanense,G.geosporum,Glomus sp.A.cavernata and A.laevis were the dominant species in these areas.2.The average AMF spore density was 242 per 50 g air-dried soil,ranging from 33 to 925.The average species richness was 10.3.Shannon-Wiener index and Simpson index ranged respectively from 1.12 to 2.55 and 0.57 to 0.91.AMF can infect the roots of Taxus chinensis var.Mairei in different sampling sites and form typical vesicular arbuscular mycorrhizae.Infection-rate ranged from 18 % ~82 %.The enzymes showed that the natural forest’s enzymes expressed better than the plantation in generally.Correlation analysis showed that EE-GRSP had a negative correlation with pH value(P<0.05)and EE-GRSP had a significantly negative correlation with T-GRSP(P<0.01);T-GRSP had a significantly positive correlation with urease(P<0.01)and the correlation coefficient is 0.742.3.The AWCD and diversity index in different sampleplots showed that L1(Damei Village,Zhejiang Province),L4(Dayao Village,Zhejiang Province)to high sampling,L2(Duntou Village,Zhejiang Province)to lower sampling.The AWCD and diversity index showed that the natural forest’s AWCD and diversity index expressed better than the plantation in generally.The carbon sources mostly used by soil microbes were Carbohydrates,Amino acids,Carboxylic acids and Polymers.4.The results of DGGE showed that there were some differences in the number,mobility and band strength of DGGE lines,indicating that the AMF community structure of Taxus chinensis var.Mairei was different,and the Shannon index and species richness has a difference.According to the similarity matrix,the similarity of each origin was different,the maximum similarity was 76.9%(3 and 10).Similarity of less than 10% had 8 groups,similarity of more than 50% had 11 groups.The results of cluster analysis showed that DGGE patterns of Taxus chinensis var.Mairei were divided into three groups:(1)6,7,8,9;(2)1;(3)2,3,4,5,10,11,12.5.Compared with CK,inoculation with PSB + AMF,PSB and AMF significantly increased the content of bacteria,fungi and actinomycetes in rhizosphere of Taxus chinensis var.mairei,and increased the utilization rate of soil microbial carbon and the change of biodiversity.The results showed that the acidity phosphatase,dehydrogenase,invertase activity,biomass,seedling height and ground diameter of each treatment group were the highest in double inoculation of PSB + AMF,PSB and AMF were centered,CK were lowest.These results indicated there were synergistic benefits between PSB(Sinorhizobium meliloti CHW10B)and AMF(Glomus constrictum).Moreover,the growth-promoting effect of co-inoculation depend on the increase of the number of culturable microorganisms in rhizosphere soil of Taxus chinensis var.Mairei,soil enzyme activity and soil biodiversity which lead to soil the enhancement of the microbial carbonutilization and soil fertility.