转Cry1Ac活性杀虫蛋白及慈菇蛋白酶抑制剂B基因的棉花

根据植物基因的结构特征。合成了Cry1Ac活性杀虫蛋白的编码序列并与内质网定位肽编码序列组成嵌合杀虫蛋白基因Bt29K。构建了含Bt29K基因及慈菇蛋白酶抑制剂B（API-B）基因表达框的双抗虫基因植物表达载体。通过根癌土壤杆菌（Agrobacterium trmefaciens(Smith et TOwnsend)ConnLBA4404)介导转化了棉花（Gossypium hirsu-tunL.)的两个生产品种（系）。根据抗棉铃虫（Heliothis armigera)试验及农艺性状的观察调查结果。经6代筛选,获得了抗棉铃虫90.0%_99.7%且农艺性状优良的9个双价抗虫棉纯合品系。分子生物学分析结果表明,两个抗虫基因在棉花基因组中的插入拷贝数为1个或2个,活性Cry1Ac和API-B蛋白在转基因抗虫棉株系中的表达量分别约占总可溶性蛋白的0.17%和0.09%。对双抗纯合系植株及仅转Bt基因的棉花纯合系抗虫性检测结果表明前者的抗虫性明显高于后者,因此推断本研究采用的双抗虫基因表达载体构建策略是合理的。     

试用灰色局势决策原理综合评价大豆新品种

根据灰色局势决策原理,利用目标赋权获得加权局势决策方法,对1996—1997年山东省大豆新品种区域试验结果进行分析,综合14个主要性状指标,排出各个品种的优劣,结果与生产实际一致。认为这是一种较全面、较合理的综合评价大豆品种优劣的方法。     

赤芝一共生菌发酵过滤液中的新倍半萜酯

从四川野生赤芝(Ganoderma lucidum (Leyss. ex Fr.) Karst.)的一共生菌Calcarisporium arbuscula Preuss的发酵过滤液中分离得到3个新的倍半萜酯类化合物,分别命名为calcarisporin B2 (1)、B3 (2)和B4 (3),通过物理方法和波谱分析确定了它们的结构.     

Angiostatin基因真核表达载体的构建及对B16黑色素瘤体内生长抑制作用

Angiostatin是一种新发现的对肿瘤生长有特异抑制作用的抗血管生成因子,实验已证实其对多种肿瘤有明显的抑制作用.本文报告构建了含Angiostatin基因的真核表达载体pAG3,通过建立荷瘤小鼠模型来研究Angio-statin对人黑色素瘤B16的原位生长,植入及与化疗药物DTIC的联合作用等来探讨Angiostatin裸DNA肌肉注射的体内抗瘤效应.实验结果表明Angiostatin可明显抑制C57荷瘤小鼠的肿瘤生长;人黑色素瘤B16细胞植入前5天肌肉注射pAG3能显著阻止正常C57小鼠新肿瘤的形成;但在pAG3与DTIC联合化疗实验中,两者未表现出明显的增强效应.本实验为拓展非病毒介导的Angiostatin抗血管生成基因治疗途径奠定了基础.     

水稻体细胞无性系变异

水稻体细胞无性系变异研究取得了很大进展,获得了大量抗病、抗逆、优质、矮杆等突变体。对这些突变体遗传分析表明,大多数突变性状由1对或2对基因控制。水稻体细胞无性系变异的发生与基因型、性状、继代时间、培养方式等有关,并具有内在的机制,点突变和反转录转座子插入可能是引起水稻无性系变异的两个重要原因。     

黑杨萎蔫叶片挥发性物质的成分分析

采用水蒸气蒸馏法和气体吸附法提取黑杨萎蔫叶片的挥发性气味物质,用二氯甲烷做萃取剂,气相色谱_质谱联用技术分离和鉴定萃取到的气味物质的化学组分,结果表明,水蒸气蒸馏法共得到19个峰,鉴定出结构的有16个峰,未鉴明的3个峰;主要组分为4号峰的(Z)_3_己烯醇,相对含量为28.71%,其次为14号峰的邻羟基苯甲醛,相对含量为10.35%。气体吸附法共分离到20个峰,鉴定出结构的有17个峰;主要组分分别为6、7、8号峰的(E)_2_己烯醛、(Z)_3_己烯醇、(E)_2_己烯醇,相对含量分别为20.78%、29.12%、29.22%。两种方法所得到的相同组分为9种,相似性为46.15%。     

T型钙通道α1G亚单位在细胞增殖中的功能研究

Increases of functional T-type calcium channel (T-channel) expression have been associated with cellular proliferation although evidence for this remains controversial. In the present study, we have used a variety of cellular, molecular and electrophysiological techniques to test the hypothesis that T-type channels play a causal role in the signaling pathway leading to proliferation. The results showed that stable over-expression of alpha1G T-channel subunit in HEK-293 cells conferred a significant growth advantage. Thus, cell population doubling time was reduced to 13.7 +/- 0.3 h in alpha1G transfectants, compared to control cultures (22.1 +/- 1.1 h) and flow cytometry analysis showed that this was due to a reduction in the number of alpha1G transfectants residing in the G0/G1 phases of the cell cycle compared to controls. The selective T-type calcium channel blocker, mibefradil, induced a dose-dependent inhibition of proliferation in alpha1G tansfectants. Furthermore, the Western blotting results proved that the level of protein expression of CDK2, cyclin A and cyclin E was high in alpha1G transfectants compared to control cultures. Our results demonstrate that the T-type calcium channel provides a significant growth advantage to HEK-293 cells that might occur via effects on the G1/S cell cycle mechanism.     

Variation of pollination and resource limitation in a low seed-set tree, Liriodendron chinense (Magnoliaceae)

Pollen limitation and resource limitation have been documented as the major factors responsible for plants commonly producing more ovules than seeds, but few studies have examined pollen deposition directly in natural populations at different sites and times. We investigated the causes of low seed set in four populations of Liriodendron chinense (Magnoliaceae), an insect‐pollinated endangered tree endemic to southern China, over 2–3 years. One pistil potentially produces two ovules. The number of pistils per flower varies among populations, but in three of the four populations the variation in a given population was not significantly different among years. Overall, populations with higher pistil numbers tend to set more seeds per flower, but a positive correlation between pistil numbers and seed production per flower was observed in only one of the four populations. The numbers of pollen grains deposited per stigma varied from 0 to 60. The proportion of pollinated stigmas per flower ranged from 44% to 88% among populations and years. The numbers of pollen grains deposited per stigma and the percentages of pollinated stigmas were significantly different between populations, and two populations showed significant differences between years. A positive correlation between stigmatic pollen load and seed set was sought in ten population‐by‐year combinations but, in a given population, high stigmatic pollen loads did not always result in high seed set. Examination of pollen deposition, pistil and seed production over several sites and years showed that in addition to pollination, other factors such as resource or genetic loads were likely to limit the (lower than 10%) seed set in L. chinense. It appears that small, isolated populations experience severe pollination limitation; one population studied had seed/ovule ratios of 0.84% and 1.88% in 1995 and 1996. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 140 , 31–38.     

牛蛙视网膜诱导型一氧化氮合酶免疫组化定位

用免疫组织化学方法研究了诱导型一氧化氮酶（iNOS)在牛蛙视网膜中的表达。结果显示,在正常状态视网膜中,无长突细胞呈弱阳性反应;节细胞层、双极细胞,水平细胞和光感受器内段呈阴性反应,在暗适应状态下,神经节细胞,内核层的无长突细胞呈强阳性反应;一些双极细胞,水平细胞和光感受器内段呈弱阳性反应,提示NO主要在暗适应状态下参与视网膜的信息传递过程。     

皱叶留兰香迁地栽培后的营养成分及抗性指标测定

皱叶留兰香 (ＭｅｎｔｈａｃｒｉｓｐａｔｅＳｃｈｒａｄ .ｅｘＷｉｌｌｄ .)为唇形科薄荷属 (ＭｅｎｔｈａＬ .)多年生宿根草本植物 ,原分布于地中海沿岸 ,我国云南及贵州等地也有分布。皱叶留兰香及薄荷属某些种类 ,在民间被广泛药用和食用。具有疏风散热、辟秽解毒之功效 ,常用于外感风热、头痛、目赤、食滞气胀、口疮、牙痛等症[1 ] ,现代研究表明薄荷属植物还具有抗病毒、杀菌、抗刺激、利胆[2 ] 及放疗区域皮肤保护[3] 等作用。食用则具有清凉芳香的口味特点 ,在我国西南地区已经成为普通蔬菜 ,广泛用于调料、生食和火锅等。作者对皱…