【作者】 焦晓国；

【导师】 张国安；

【作者基本信息】 华中农业大学 ， 农业昆虫与害虫防治， 2001， 硕士

【摘要】 本文以转Bt基因[cryIA(b)/cryIA(c)]水稻恢复系明恢63(T51-1)的后代及其所配制的汕优63/Bt、Ⅱ优/Bt、马优/Bt为材料，汕优63、明恢63为亲本对照，较系统研究了转Bt基因水稻对三化螟的抗性时空动态表达及对稻田主要害虫和天敌消长动态的影响，旨在为转Bt基因水稻害虫的综合治理提供理论依据。 室内运用离体叶片和离体茎秆两种方法对三化螟的抗性进行了测定，表明转Bt基因水稻对三化螟幼虫具有很强的抗性，致死率达100％，与田间人工接虫鉴定结果一致。同一生育期转Bt基因水稻不同组织对三化螟抗性存在差异，叶的抗虫性显著低于茎秆。不同生育期转Bt基因水稻叶片对三化螟抗性也存在差异，孕穗期叶片显著高于三叶期。不同龄期的三化螟幼虫对转Bt基因水稻的耐受性也存在差异，3龄幼虫的耐受性要高于初孵蚁螟。 以转Bt基因水稻为参照，在自然感虫和大田人工接虫相结合条件下，对40个不同水稻品种进行了抗虫性初步鉴定，分别筛选出对稻飞虱(白背飞虱、褐飞虱)、稻纵卷叶螟、三化螟具有抗性的不同水稻品种，为进一步利用其抗源提供了理论基础。 在自然感虫和大田人工接虫相结合条件下，通过8次系统调查，研究结果表明，4个不同转Bt基因水稻品种对三化螟、稻纵卷叶螟有极强的抗性，抗虫率达100％；三化螟和稻纵卷叶螟不能在转Bt基因水稻上完成生活周期，转Bt基因水稻对它们不能起到抗性筛选作用。但转Bt基因水稻对稻飞虱(白背飞虱、褐飞虱)没有抗性，初步结果表明转Bt基因水稻对稻飞虱有一定的超感作用。转Bt基因水稻上蜘蛛混合种群数量与常规稻相比没有显著差异，表明转Bt基因水稻对稻田主要捕食性天敌蜘蛛没有不良影响。 转Bt基因水稻对螟虫的控制，使稻飞虱成为转Bt基因水稻田主要害虫类群，蜘蛛成为其稻田主要捕食性天敌。应用天敌功能指数探讨了转Bt基因水稻上蜘蛛对稻飞虱的控制作用，为转Bt基因水稻田稻飞虱综合防治提供了理论依据。同时探讨了化学农药吡虫啉对转Bt基因水稻田蜘蛛和稻飞虱消长动态的影响，结果表明其对稻飞虱和蜘蛛都有一定杀伤作用，但吡虫啉对稻飞虱有特效，对蜘蛛的影响较小。 本研究为及时评价转Bt基因水稻的抗性风险、预测其推广应用前景以及建立以转Bt基因水稻为基础的害虫综合治理体系提供了理论依据。更多还原

【Abstract】 The resistance to yellow stem borer (YSB)and influences on main pests and natural enemies in rice field were studied using the transgenic indica rice CMS restorer line Minghui63(T51-l) and its derived varieties, II you/Bt,Shangyou63/Bt, Mayou/Bt, expressing a Bt fusion protein derived from crylA(b) and crylA(c) sequences, Shangyou63 and Minghui63 as the control varieties.Using the two methods of "detached leaf bioassay" and "detached stem bioassay", both of the laboratory bioassay showed that T51-1 was highly resistant to the newly hatched YSB with the moralities of 100% after 72h, the laboratory bioassay results of the two methods were quite coincident with those of the whole plant manual infestation in rice field. The resistance of transgenic Bt rice to YSB varied with the rice structures and its developmental stages. The resistance of Bt rice in leaf to YSB was lower.than that of the stem; on the other hand, the resistance of Bt rice at spike formation stage to YSB was higher than that at tree-leaved stage. With the difference of instar, the resistance of Bt rice to the YSB was also different. The 3rd instar larvae was more resistant to Bt rice than the 1st instar larvae.The transgenic Bt rice(T51-1) looked as a criterion, forty different normal rice varieties were carried out to select the resistant varieties to the main different pests ,such as the YSB, leaffolder ,and rice planthopper( including the White-backed planthopper and the Brown planthopper).Systematic studies were carried out on effects of transgenic Bt rice on population dynamic of the main pest and their natural enemies in rice field .The result showed that transgenic Bt rice was highly resistant to YSB,leaffolder; but it was not that resistant to the rice planthopper, on the contrary, there were more rice planthoppers in Bt rice than in normal rice varieties. Luckily, there were not any significant difference of the number of spiders on transgenic Bt rice than on normal rice in the field, it was assessed that there were no harm to spiders in transgenic Bt rice field.The transgenic Bt rice was very resistant to the main Lepidopterous pests, such as the YSB and leaffolder ,It was not obviously easy to find the two kind pests in transgenic Bt rice field. But the rice planthopper was easy to break heavily in transgenic rice field .We used the index of the enemy function to assess the natural enemy -spiders’ control action to the rice planthopper, The result showed that the spiders’ control action was very obvious when the number of the rice planthopper was under the control threshhold , otherwise, we should take action immediately to decrease the number of the rice planthopper, using the agriculture insecticide-Bichonglin ,which was very effective to control the rice planthopper and do little harm to the spiders.更多还原