The Study Of The Rhizosphere Microorganisms Of Poyang Lake Wetland Plant Under Zinc And Lead Stress

Phragmites communis and C.leucochlora Bunge from Poyang Lake were studied based on different concentrations of Zinc and Lead with pot experiment. And the influences of Zinc stress on structure and functional diversity of rhizospheric microorganism was analyzed by the Biololg method. And Using traditional microbiological culture method, through determination of the amount of rhizospheric bacteria、actinomycetes and fungi, the tolerance of Phragmites communis and C.leucochlora Bunge to Zn2+and Pb2+was studied. The results showed in the following:(1) For Phragmites communis, the metabolic ability of microbial community was decreased after Zinc stress; The metabolic ability of microbial community of80and110mg/l Zn2+are higher than other microbial community Zinc stressed;Zn2+at the concentration of10mg/l can increase the diversity of rhizospheric microorganism; For C.leucochlora Bunge, the metabolic ability and functional diversity of microbial community of at50mg/l Zn2+increased.but decreased at80and110mg/l Zn2+(2) Under Zinc stress the metabolic ability of polymers、carboxydrates、 phenols and amino acids of microbial community increased but metabolic ability of carboxylic acids decreased; the six main carbon source types possess highest utilization efficiency at50mg/l Zn2+(3) Tolerance of C.leucochlora Bunge to Zinc higher than Phragmites communis;(4) Polymers、amino acids and carboxydrates are the main carbon source for all treatment rhizospheric microorganism;principal component analysis revealed that utilization of specific carbon source is different for different treatment;(5) Zinc stress increased the amount of rhizospheric bacteria and fungi of Phragmites communis and the amount of actinomycetes is complex under different concentrations of Zinc;For C.leucochlora Bunge.the concentrations of Zn2+exceeding20mg/l can obviously reduced the amount of bacteria and with the increasing of concentration of Zn2+,Inhibition increased;Zinc stress can stimulate actinomycetes and fungi of C.leucochlora Bunge, when the concentrations reaches110mg/l,the amount of them decreased and flat with the control;Generally, rhizospheric bacteria、actinomycetes and fungi of C.leucochlora Bunge are more sensitive to Zn2+than Phragmites communis’s;(6) For Phragmites communis the sensitivity reflection order of3microbes to Zn2+was actinomycetes>bacteria>fungi but for C.leucochlora Bunge the sensitivity was bacteria>fungi>actinomycetes;(7) Under the same concentration of Pb2+, the amount of bacteria、 actinomycetes and fungi with water lever were obviously higher than the without. Rhizospheric bacteria of C.leucochlora Bunge are more sensitive to Pb+than Phragmites communis’s but the sensitivity reflection order of actinomycetes and fungi to Pb2+was Phragmites communis> C.leucochlora Bunge.(8) In generally, the advantages of the three rhizospheric colonies distribution are:bacteria> actinomycetes> fungi.