In order to evaluate ecological safety of transgenic insect-resistance hybrid poplar 741, the diversity of soil microflora and Bt toxin protein were systematically studied in the growth season. Four-year-old transgenic poplar 741 in the Heneshui district and Baoding district were examined. The toxin protein was found in the soil of 4 year old test groves, whose peak content appeared in rhizosphere, and the longer the distances off the roots, the lower the contents. The distribution of toxin protein showed a descending trend: root tissue>root surface soil>rhizosphere soil>surface soil. The concentration of toxin protein decreased by degree of 10 times among different parts of soil. No toxin protein was found in rhizosphere of non-transformed clones. In the rhizosphere and roots surface soil of 4 year old test groves, the amount of bacteria and actinomycetes and fungi varied with the changes of season. In spring, their amount began to increase gradually, reaching the maximum in June and July, and then decreased gradually. Between different transgenic clones and nontransgenic controls, during different seasons, there were differences but no significant difference of their amounts appeared in rhizosphere and roots surface soil. The existence of toxin protein in soil showed no significant influence on the amounts of fungi, bacteria and actinomycetes. The result showed that distribution of Bt toxin protein was not related to the amount of microorganism. Transgenic poplar is ecofriendly in the grittiness soil.
Authors: Zhen, Zhixian; Wang, Jinmao; Yang, Minsheng. ;Full Source: Hebei Nongye Daxue Xuebao 2011, 34(1), 78-81 (China). ;