关键词: 杂交稻, 杂交稻, 天优673, 航天育种

Abstract:

In order to clarify the entironment’s effect characters of the pesticide’s residue in the purplish soil and the soil microorganisms’ response mechanism, using purplish soil, which is the most representative soil types in the Three Gorges Reservoir Areas, as experimental material, through pot-cultured maize and CFU method, the influences of bifenthrin’s residue on indigenous microbes quantity were researched. The results showed that, the low level of bifenthrin’s concentration had a significant promoting effect on indigenous bacteria. Different bifenthrin’s concentrations from low-level to high-level, the numbers of soil bacteria and actinomycetes had successive peak values over time: in the 6th day, the numbers of bacteria and actinomycetes of LB-L treatment reached 9.02×106 and 2.77×106 per gram soil respectively, which were about 9 and 3 times to the corresponding contrasts. In the 11th, the numbers of bacteria under LB-M treating were about 77 times to the control, reaching 5.19×107 per gram soil. In the 16th, bacterial numbers of LB-H treatment reached 1.71×107 per gram soil. Meanwhile, the numbers of actinomycetes of LB-M and LB-H treatments were 4.04×106 and 4.35×106 per gram soil respectively. Secondly, the residual bifenthrin in purplish soil showed a significant and rapid inhibition effect on indigenous fungi, even under the 2.50 mg/kg bifenthrin level, the numbers of fungi would significantly decrease after bifenthrin applied in the following day. Thirdly, the main three groups of indigenous microorganisms in purplish soil showed the certain ecological suitability to the residual bifenthrin. But the representations were quite different: there was a bifenthrin’s concentrational threshold level to ecological response of indigenous bacteria, while indigenous actinomycetes showed a long and stable promoting effect. However, indigenous fungi showed a recoverable and inhibitory effect. The results of experiment showed that, soil microbes and other biological factors could be used as the important evaluation index for the bifenthrin’s contaminated rhizosphere microecology of the purplish soil.