FISH analysis of the integration patterns in transgenic rice co-transformed by microprojectile bombardment

Using multi-color fluorescencein situ hybridization (FISH), we localized transferredbarnase-ps1 andpHctinG DNA sequences onto chromosomes of two transgenic rice plants, named Q12 and Q13, both of which were produced by micro-projectile bombardment. In both Q12 and Q13, each detected cell showed 2–3 signal spots on their chromosomes respectively. The signals of bothbarnase-ps1 andpHctinG were mostly detected in the adjacent chromosomal sites in which their signals were overlapped and could be recognized by the signal color on the metaphase chromosomes. Fiber FISH further demonstrated that the multiple copies in each of the two DNA sequences distributed adjacently on the DNA fiber in Q13. Combined with the results of Southern hybridization, the possible integration patterns in transgenic rice co-transformed by micro-projectile bombardment have been discussed.     

Inheritance and expression of multiple disease and insect resistance genes in transgenic rice

2—3 anti-fungal disease genes are coinserted with hygromycin phosphotransferase in the same vector. Two insecticidal genes and PPT acetyl transferase genes are placed in another one. The vectors are co-delivered to rice embryonic cellus tissue at a molar ratio of 1︰1 using the particle gun method. 55 independent regenerated lines have been obtained through screening for hygromycin resistance. Of these, 70% transgenic plants harbor 6—7 foreign genes. The genes on the same vectors are always co-delivered to rice plant. Northern blot analysis has indicated that the multiple foreign genes give stable expression. In the 6 transgenic plants carrying 6—7 foreign genes, multiple foreign genes tend to integrate in 1 or 2 genetic loci. Progeny segregation is consistent with Mendel’s 3︰1 segregation law. 8 homozygous R₁ transgenic plants harboring 2—3 anti-fungal and 2 insecticidal genes are selected from large number of transgenic progeny screening for hygromycin and Basta resistance.     

二灰碎石的抗拉性能

抗拉强度是二灰碎石的主要力学性能之一,研究表明,集料级配、集料最大粒径、养生条件和龄期对二灰碎石的劈裂抗拉强度有很大影响。最大粒径愈小、颗粒愈细,二灰碎石的劈裂抗拉强度就越高;二灰碎石的劈裂抗拉强度随养生温度的提高或龄期的增长而提高。     

水稻田甲烷排放机制及影响因素

稻田产甲烷菌所产生的甲烷相当一部分被甲烷氧化菌所分解 ,剩余部分主要通过水稻植株释放 ;土壤Eh、土壤类型、施肥种类等均对甲烷排放通量产生影响     

米糠多糖的提取及其含量的测定

对米糠中的多糖进行提取与测定,采用水提醇沉法对米糠中的多糖进行提取,并采用苯酚—硫酸法测定其多糖含量,以正交实验优化显色条件。确定检测波长为490nm,确定6%苯酚用量为1.0mL,浓硫酸用量7.5mL,反应时间为30min。在(0.0025—0.030)mg/mL范围内,呈良好的线性关系。平均回收率为97.8%,RSD=3.89%(n=6)。测得米糠粗多糖含量为20.2%。结果表明方法简单、准确,为继续研究开发提供一定的参考依据。     

SH-1型组装式大型浮标的设计

针对整体式大型海洋资料浮标海上生存能力不强，加工制造、布放运输不便等问题，设计了一种直径为6 m的组装式的大型浮标。利用船舶静力学的计算方法，确定了浮标的型深为2.2 m、重心高为0.9 m以及其他基本参数，并对浮标的稳性衡准数进行校核，结果满足使用要求。该设计为浮标加工质量的可控性提供了合理化依据。     

风水联合冷渣器在运行中的问题分析及改进

风水联合冷渣器广泛应用于大型循环流化床锅炉,但在运行中出现了诸多问题.针对某电厂风水联合冷渣器在运行中出现的问题,提出了改进措施与建议.     

轻型动力触探确定粉煤灰地层承载力的可靠性分析

通过工程实例论述采用轻型动力触探法确定粉煤灰地层地基承载力的方法,并对该方法的可靠性进行分析,并就此提出了结论。     

无机填料对聚氨酯仿瓷砖性能的影响

以聚氨酯为胶料、粉煤灰和CaCO₃为填料制备了仿瓷砖，进行力学性能测试和SEM扫描分析。结果表明，填料的添加量为72~78%、压制强度为21~109 MPa时，添加粉煤灰和CaCO₃的仿瓷砖的最大破坏强度为3 300 N和2 300 N，最大断裂指数为50 MPa和35 MPa，最小耐磨损体积分别为289 mm³和445 mm³，最小吸水率为0.95%和0.85%。粉煤灰的综合增强作用好于CaCO₃。     

粉煤灰综合利用现状及前景

阐述了粉煤灰的来源、危害及物理和化学性质,介绍了煤灰综合利用的发展历程,探讨了粉煤灰的用途和应用现状,展望了粉煤灰的利用前景。