| Depend on metabolic substances, phosphate-dissolving microorganisms themselves or collaboratedwith other organisms dissolve phosphate, which was bind on soil as a state of un-capable use. Therefore,microorganisms pay important role in the transform of phosphate. Some research indicated thatphosphate-dissolving fungi have more stable and strong ability in this process then bacteria. This thesisreported research on the screening of phosphate-dissolving fungi, evaluation of ability of dissolvingphosphate and effect on the stimulating growth of wheat seedlings. An isolate of Penicillium oxalicumP-o-41 was found from more then 100 isolates in the study based on four pot experiments conducted ingreenhouse. The results showed that height of wheat seedling in the group treated by isolate P-o-41 washigherthen non-treated CKin three experiments. The difference wassignificantbased on statistic analysis.The fresh weight of seedlings was higher responding to the treatment of the isolate in one experiment. Inanother experiment, weight of fresh roots was higher. Although two samples mentioned above are notstable in all experiments, however, the data collected from all experiments showed that all index in group,which was treated with P-o-41 were better then CK, but no statistic significant difference. In thefermentedsolutionofPenicilliumoxalicum P-o-41,wefoundIAAinquitehighconcentration.Itmayrelategrowthpromotingofseedlingsaswell.This thesis reports that fermented solution of P-o-41played action of SAR if the solution was diluted to1000 times. Evidence of the function was obtained from Thanxin tobacco–TMV testing system. Inhibitoryrate of spots on leaves of Thanxin tobacco was 84.05% and 79.96% separately. Controlling powderymildewofwheatwith spreading solution of P-o-41 diluted for1000 timesand BTH,the effectsreached to60.88%and69.43%separately.However,theactivesubstanceisstillunknown. |
