The Effect Of Bt-transgenic Rice On Environmental Microbes

According to rice's different growing period, we gathered the root surrounding soil samples of Bt rice and non-Bt rice of different fertilities, respectively on June 23, 2009, August 18, 2009, October 21, 2009. We study the amount and carbon metabolism of soil microbe organism. And we study the changes of the basic phenotype, physiological and biochemical properties and its resistance to pathogen disease of Bt rice that planted in greenhouse. The major findings are as follows:1.The total stomata number of non-Bt rice is more than that of Bt rice, the stomata lengths of Bt rice and non-Bt rice are similar. There is no significant difference between the size and ornamentation of Bt rice and non-Bt rice pollen.2.The soluble protein contents in the leaves and roots of Bt rice and non-Bt rice are in the same trends, that the highest levels in the booting stage, declined again to mature stages. There was no significant difference between the soluble protein content in the leaves and roots of Bt rice and non-Bt rice for the same growing period and fertilizer. The trend of soluble sugar content in the leaves and roots of Bt rice and non-Bt rice during the growing stage is the same as soluble protein. There was no significant difference between the soluble sugar content in the leaves and roots of Bt rice and non-Bt rice for the same growing period and fertilizer. The soluble protein content of Bt rice pollen is significantly lower than non-Bt rice in the first a few collection days and is significantly higher in the last day. The soluble sugar content of Bt rice pollen is generally higher than non-Bt rice and there are significant differences between the first, the third and the fifth day.3.Different amounts of Bt protein are expressed in leaf, root, which the expression of leaves is the most, followed by roots, and the expression of pollen is less than that of leaves and roots. Root exudates expression is least.4.The microbe number is more or less affected by sampling time, fertilization, rice varieties. The numbers of aerobic bacteria and facultative bacteria, fungi, anaerobic bacteria, nitrification bacteria gradually increase with the growth of rice and are most at mature stage, that actinomycetes number is most at booting stage; The numbers of fungi, anaerobic bacteria increase with more fertilizer; Compared with non-Bt rice, the aerobic bacteria and facultative bacteria number of Bt rice increases significantly; The interaction of sampling time and the fertilization has significant effects on the number of anaerobic bacteria. Interaction of rice varieties and fertilization and the interaction of sampling time, rice varieties and fertilization have effects on the amount of nitrite bacteria; other interactions have no significant impacts on microbe numbers. 5.Bt rice planting doesn't result in the reduction of microbial activity of root surrounding soil. There are no significant changes in soil microbial activities of different fertilization samples. Bt rice planting doesn't cause changes in metabolic diversity of soil microbial communities, microbe surrounding non-Bt rice roots is more sensitive to fertilizers, rational fertilization can increase the diversity of microbial metabolism. The carbon numbers and types used by soil microbe of the rice at different treatment during the growing conditions are not the same, microbes in the soil which have higher activities use more kinds and quantities of carbon source. Carbon metabolic activity of Bt rice epiphytes microbe doesn't change significantly, the carbon metabolic activity is weaker relative to the non-Bt rice, the total carbon numbers it use is less. Bt rice will not cause the change in metabolic diversity of epiphytes microbe community.6.Compared with non-Bt rice, The incidence rate and disease index of Bt rice inoculated with typical pathogen diseases Pyricularia oryzae Cavara were higher. the average lesion length was significantly higher than non-transgenic rice plants. No dead plants appeared; Similarly, The incidence rate and disease index of Bt rice inoculated with bacterial stripe were higher. No dead plants appeared.