转基因食品安全性问题的研究现状

近年来转基因食品在世界范围内发展迅速,人们对转基因食品的安全性也日益关注。文章介绍了转基因食品的发展现状、转基因食品安全性研究的内容、评价原则。     

草莓的保鲜现状研究

草莓味道鲜美,受到人们的喜爱,但是却难以保藏。目前,草莓的保藏方法主要是控制温度,并使用保鲜剂进行贮藏。控制温度一般通过冷藏库实现。草莓控温在冰点以上进行冰温贮藏比普通的冷藏效果要好。而使用气调库、气调包装则能更好地保持草莓的新鲜度。     

不同浓度盐胁迫对转基因饲用甜菜种子萌发及幼苗生长的影响

通过不同浓度NaCl溶液处理转基因饲用甜菜种子及其幼苗试验，研究了盐胁迫下种子萌发、幼苗生长及胁迫解除后种子的效应，为盐土农业生产提供理论依据。结果表明，转基因饲用甜菜种子萌发的适宜Nacl浓度为50。150mmol/L，其中100mmoL／LNaCl胁迫下，种子发芽率最高，与对照相比高6．78％。随着盐胁迫浓度的升高，种子萌发延迟，萌发率也呈不同程度的降低。盐胁迫解除后，种子萌芽迅速，萌芽率提高，整齐度增加。转基因饲用甜菜幼苗在不同NaCl浓度胁迫下表现出的反应不同，高盐胁迫对抑制幼根生长影响较大。     

实时荧光PCR技术定量检测转基因大豆方法的研究

以转基因大豆Roundup Ready为材料，通过特异性引物和探针，对转基因大豆中外源基因cp4-epsps进行了定量检测。研究发现Taqman荧光探针法和SYBR荧光染料法均可作为转基因大豆定量检测的方法，但前者比后者具更高的检测灵敏度和精确度，其检测阈值可降到0.05%，变异系数为0.09%~0.53%。在此基础上，建立和优化了Taqman探针实时荧光定量PCR检测技术体系，有助于提高转基因作物及产品的生物安全性定量检测的准确度和可靠性。     

QTL遗传效应正反交差异研究

应用改良AD模型对转基因棉花QTL突变体系进行遗传效应的正反交比较分析,结果表明,农艺性状的主要遗传方差组分分解正反交表现一致,除铃重存在显著的遗传背景加性效应(A2)外,子棉产量、皮棉产量、衣分和铃数均存在显著或极显著的 dQTL加性效应(A1)和显性效应(D1),农艺性状均有显著或极显著的遗传背景显性效应(D2);棉花纤维性状的主要遗传效应正反交之间无显著差异.铃重的dQTL的加性和显性效应与环境的互作存在显著差异.对转基因系、受体及三个品系的dQTL加性效应分解结果也表明,正反交对不同材料各性状的加性效应估计也是一致的.本文还对不同组合正反交时的纯合及杂合显性效应进行预测比较.     

转基因植物食用安全评价

2014年全球转基因植物种植面积达到1.815亿hm2,转基因植物商业化发展给全球农业和环境带来巨大收益,但是其安全性问题仍然受到广泛争议。目前,对转基因植物的安全评价在全球范围内已经建立起较为完善的体系,但是各国政府对评价程序的具体要求还存在差异。为了在法律法规层面规范转基因植物安全评价程序,中国农业部颁布了《转基因植物安全评价指南》,涵盖了详细的转基因植物及其产品的安全性评价内容。本文结合案例分析,对该指南中的食用安全评价部分详细解析和论述了包括营养学、毒理学、致敏性以及非期望效应等安全评价程序,旨在为我国转基因植物的食用安全评价提供有益的指导与借鉴。     

Long-term monitoring of feral genetically modified herbicide-tolerant Brassica napus populations around unloading Japanese ports

Genetically modified, herbicide-tolerant (GMHT) Brassica napus plants originating from seed spill have recently been found along roadsides leading from Japanese ports that unload oilseed rape. Such introductions have potential biodiversity effects (as defined by the Cartagena Protocol): these include replacement of native elements in the biota through competitive suppression or hybridization. We conducted surveys in the period 2006–2011 to assess such threats. We examined shifts in the population distribution and occurrence of GMHT plants in 1,029 volunteer introduced assemblages of B. napus, 1,169 of B. juncea, and 184 of B. rapa around 12 ports. GMHT B. napus was found around 10 of 12 ports, but its proportion in the populations varied greatly by year and location. Over the survey period, the distributions of a pure non-GMHT population around Tobata and a pure GMHT population around Hakata increased significantly. However, there was no common trend of population expansion or contraction around the 12 ports. Furthermore, we found no herbicide tolerant B. juncea and B. rapa plants derived from crosses with GMHT B. napus. Therefore, GMHT B. napus is not invading native vegetation surrounding its populations and not likely to cross with congeners in Japanese environment.     

Reciprocal recurrent selection for multitrait indices in maize

Summary Reciprocal recurrent selection was carried out with two populations of maize (Zea mays L.) having good combining ability. We selected for higher grain yield, early maturity, shorter plant height and lodging resistance. Two cycles were completed in two years (four seasons), by resorting to late planting of S1 lines for recombination in the main season in which top-cross families were assessed. Top-crosses and selfings were made in the off-season. The original and improved versions of the populations and their crosses were evaluated in multilocation trials. The superiority of the population hybrid was 10.3% for grain yield, 5.5% for plant height and 1.8 days to silk. The improved hybrid had delayed leaf senescence and better resistance to lodging and post-flowering stalk rots. Among the yield components, only ear girth showed improvement. Syn 2 of the improved population cross showed a yield reduction of 6.2% in comparison to Syn 1. Intrapopulation gains were not significant except for lodging resistance in one population.     

猪卵母细胞在不同条件下的体外成熟培养

研究了不同时间段添加外源激素及不同基础培养液和血清有无对猪卵母细胞体外成熟的影响。实验包括（1）猪卵母细胞以TCM199＋10％FBS＋10IU／mL pregnant more serum gonadotrophin（PMSG）＋10IU／mL human chorion gonadotrophin（hCG）＋2．5IU／mL follicle stimulate hormone（FSH）为成熟培养液体外培养44h，前22h在培养液中加激素，后22h不加激素及前22h不加激素，后22h添加激素和添加激素连续培养44h；（2）以实验（1）中激素添加的方案在体外添加激素连续培养44h，对不同基础培养液（TCM199粉剂、TCM199原液和改良TCM199（mM199））对猪卵母细胞体外成熟进行了研究；（3）以实验（2）中筛选出的mM199组为成熟培养液对比血清有无对猪卵母细胞体外成熟的影响。结果表明，实验（1）中3种激素添加不同时间段其成熟率分别为45．67％、45．29％和46．07％，对猪卵母细胞体外成熟无显著影响（P〉0．05）；实验（2）中，mM199组的成熟率（54．10％）高于TCM199粉剂组的成熟率（46．16％）及TCM199原液组的成熟率（47．14％），但差异不显著（P〉0．05）；实验（3）中无血清组的成熟率（67．10％）高于有血清清组的成熟率（52．22％），差异显著（P〈0．05）。由此表明，mM199＋10IU／mL PMSG＋10IU／mL hCG＋2．5IU／mL FSH是一种适合于猪卵母细胞体外成熟的培养液，体外成熟率达67．10％。     

硝酸镧、混合稀土对甘蔗叶片多酚氧化酶和过氧化物酶活性的影响

在3个甘蔗品种的分蘖初期,分别喷施硝酸镧和混合稀土溶液,结果这两种处理都能促使甘蔗叶片在不同生长期的多酚氧化酶活性极显著高于喷清水的对照,而且喷施混合稀土的又极显著高于硝酸镧处理。混合稀土还能使即将进入工艺成熟期的甘蔗叶片的过氧化物酶活性高于对照。