【作者】 刘梅；

【导师】 肖红梅；

【作者基本信息】 南京农业大学 ， 食品工程， 2013， 硕士

【摘要】 近年来,随着转基因技术的广泛应用,尤其是华中农业大学研发的两种转基因抗虫水稻“华恢1号”和"Bt汕优63"获得转基因水稻安全证书以来,转基因水稻的商业化已指日可待,安全性评价迫在眉睫。本文以转Bt基因(CrylAc/CrylAb)稻米及其非转基因亲本稻米为材料,研究了稻米在高温高湿的贮藏环境中品质和微生物群落多样性的变化,为转基因稻米安全性评价提供数据支撑。主要研究结果如下：1、整个贮藏期间糙米的水分含量、脂肪氧化酶、电导率、脂肪酸值、丙二醛含量变化明显高于稻谷。水份含量在转基因糙米中的增加速率高于非转基因糙米,而转基因稻谷的水份含量增加速率低于非转基因稻谷；脂肪氧化酶在转基因稻谷的酶活增加速率高于非转基因稻谷；而转基因糙米和稻谷的电导率、脂肪酸值、丙二醛含量变化与非转基因稻米相比差异不显著(P>0.05);在本试验中转基因样品与其亲本非转基因样品的耐储藏性相差并不明显。相关性分析显示,贮藏时间与水分、电导率、脂肪酸值和脂肪氧化酶呈现显著性正相关。2、利用分子生物学手段变性梯度凝胶电泳分析发现,试验样品随着贮藏时间的延长,霉菌18S rDNA的DGGE图谱中泳道中的条带数目呈现递增,细菌16S rDNA的DGGE图谱中泳道中的条带数目变化不显著。稻谷霉菌的多样性低于糙米霉菌的多样性,成熟度高的转基因糙米与成熟度低的转基因糙米的霉菌相似性在25.0%到59.9%之间,转基因糙米与非转基因糙米的霉菌相似性在9.8%到67.8%之间,转基因稻谷与非转基因稻谷的霉菌相似性在54.4%到75.7%之间,转基因样品与非转基因阴性对照在贮藏过程中霉菌的多样性存在显著变化。成熟度高的转基因糙米与成熟度低的转基因糙米的细菌相似性在70.6%到93.0%之间,转基因糙米与非转基因糙米细菌的相似性在81.7%到92.8%之间,转基因稻谷与非转基因稻谷的细菌相似性在71.3%到91.8%之间。转基因样品与非转基因阴性对照在贮藏过程中霉菌和细菌的多样性存在一定的差异,而差异的原因需要进一步验证。更多还原

【Abstract】 In recent years, with the develepment of the transgenic technology, especically, two transgenic rice "Hua Hui1" and " Bt Shanyou63" have received security certificate. Study on quality changes of genetically modified rice during storage can support for transgenic rice safety evaluation. In this paper, the quality and microorganism diversity change of Bt (Cry1Ac/CrylAb) transgenic rice and non-transgenic parents (as negative controls) in hot and humid storage were studied. The main results are as following:1.The moisture content, lipoxygenase, conductivity, fatty acid value and malondialdehyde content of rice was significantly higher than brown rice during storage. The moisture content increasing rate of transgenic rice was higher than non-transgenic rice, and moisture content of transgenic brown rice increasing rate was lower than non-transgenic brown rice. After storage, the enzymes activity of lipoxygenase from transgenic brown rice was higher than non-transgenic brown rice. No significant difference (P>0.05)existed among conductivity, fatty acid value and malondialdehyde content compared genetically modified rice with non-transgenic rice. Difference of anti-storability in this study between transgenic rice and its negative controls was not obvious, however, brown rice was more resistant than rice during storage. Correlation analysis showed that days of storage, water content, electrical conductivity, fatty acid value and lipoxygenase presented a significant positive correlation, and storage days was correlated to malondialdehyde.2. The microbial diversity of different samples was analysed by using molecular biology technique of denaturing gradien gel electrophoresis during storage. The18S rDNA DGGE profile bands of fungal presented a gradually increasing trend, DGGE profile of16S rDNA lane in the number of bands had no obvious change with time prolonged. In brown rice samples, the number of bands separated from fungus fingerprint were less than that of rice samples. Among which, the similarity of fungus from high maturity transgenic rice and low maturity transgenic rice ranged from25.0%to59.9%. The similarity of fungus was from9.8%to67.8%for transgenic rice and non-transgenic rice. The similarity of fungus varied from54.4%to75.7%for transgenic samples and negative controlled group during storage. The profile results revealed that it had significant difference in fungal diversity between genetically modified samples and its negative controls. Similarity of bacteria from high maturity transgenic rice and low maturity transgenic rice ranged from70.6%to93.0%. The similarity of bacteria transgenic rice and non-transgenic rice varied from81.7%to92.8%. The similarity of bacteria was from71.3%to91.8%for transgenic samples and negative controlled group during storage. The result showed that there was certain difference on microorganism diversity between transgenic samples and negative controls, however, the reason of diversity needs further study.更多还原