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排序方式: 共有526条查询结果,搜索用时 15 毫秒
41.
XIAO-PING WANG FENG GE FANG-SEN XUE 《Insect Science》2006,13(3):189-193
The cabbage beetle, Colaphellus bowringiBaly (Coleoptera: Chrysomelidae), is a serious pest of crucifers in China, undergoing an imaginal summer and winter diapause in the soil. The effects of host plants on diapause incidence were tested in the beetle. The ratio of adults entering diapause was significantly low when they fed on the mature leaves of Chinese cabbage Shanghaiqin (Brassica chinesis var communis) than those feeding on Chinese cabbage Suzhouqin (Brassica chinesis var communis), radish (Raphanus sativus var longipinnatus) and stem mustard (Brassicajuncea vat tumida) at 25℃ combined with 13:11 (L: D) h. Fewer adults entered diapause on young leaves compared to physiologically aged and mature radish leaves at 25℃ combined with 13:11 (L: D) h. The effect of host plant species on diapause induction was also evident under continuously dark rearing conditions or at different photoperiods. These experimental results demonstrate that host plant mediation of diapause induction exists in the cabbage beetle. However, at temperatures ≤20℃ or photoperiods of 16:8 (L: D) h combined with 25℃, all individuals entered diapause regardless of the host plants, indicating that the effects of host plants on diapause induction could be expressed only within a limited range of temperatures and photoperiods. 相似文献
42.
Zhe REN Chuan-hai ZHANG Lian-jun WANG Yun-xia CUI Ren-bin QI Chong-ren YANG Ying-jun ZHANG Xiao-yi WEI Da-xiang LU** Yi-fei WANG ** 《Virologica Sinica》2010,(2)
Herpes simplex virus type 1 (HSV-1) is a commonly occurring human pathogen worldwide. There is an urgent need to discover and develop new alternative agents for the management of HSV-1 infection. Tripterygium hypoglaucum (level) Hutch (Celastraceae) is a traditional Chinese medicine plant with many pharmacological activities such as anti-inflammation, anti-tumor and antifertility. The usual medicinal part is the roots which contain about a 1% yield of alkaloids. A crude total alkaloids extract was prepared ... 相似文献
43.
黄瓜幼苗对氯化钠和碳酸氢钠胁迫的生理响应差异 总被引:8,自引:0,他引:8
采用营养液培养方法,分别用不同浓度(0、25、50和75 mmol·L-1)的NaCl和NaHCO3对黄瓜幼苗进行胁迫处理,研究黄瓜幼苗对NaCl和NaHCO3胁迫的生理响应差异.结果表明:随着胁迫强度的增加,黄瓜植株地上部和地下部生长量、叶片叶绿素含量和相对含水量均呈明显下降趋势,但NaHCO3处理下降幅度大于NaCl处理.随着处理浓度的增加,黄瓜地上部Na+含量显著上升,K+含量显著下降,在相同的Na+浓度下,NaHCO3处理比NaCl处理下降幅度更大,具有更低的K+/Na+.与NaCl处理相比,NaHCO3处理的黄瓜叶片电解质渗漏率、丙二醛、脯氨酸和可溶性糖含量增加幅度更大.NaCl和NaHCO3处理使黄瓜叶片超氧化物歧化酶、抗坏血酸过氧化物酶和脱氢抗坏血酸还原酶活性受到显著诱导,而使过氧化物酶活性受到明显抑制. 相似文献
44.
45.
拟南芥生长素受体基因TIR1启动子的克隆及序列分析 总被引:1,自引:0,他引:1
以野生型拟南芥 (Arabidopsis Columbia)基因组DNA为模板,通过PCR扩增得到拟南芥生长素受体基因TIR1启动子2008片段,将该片断克隆到PGM-T载体上.序列分析表明,该启动子大小为2008bp,RNA聚合酶识别序列TATA-box,TIR1特异表达和增强序列CAAT-box皆完整,与已报道的序列比较仅有3个核苷酸发生改变,同源性为99.85%.将该启动子与GUS基因融合,构建成表达载体后,在拟南芥和烟草叶片中做瞬时表达,结果分析显示:拟南芥和烟草叶片中均有GUS 酶活性存在. 相似文献
46.
维生素C葡萄糖苷的研究现状及发展前景 总被引:2,自引:0,他引:2
维生素C葡萄糖苷是卫生署公布认可的美白添加剂之一,利用糖基转移酶的特异性转糖基作用进行生物转化合成是目前维生素C葡萄糖苷的唯一生产途径。对维生素c葡萄糖苷的生产方法进行了讨论,着重阐述了其制备(生物转化合成法)、纯化及结晶三大生产工艺的国内外研究现状,指出国内实现维生素C葡萄糖苷工业化生产的发展方向。 相似文献
47.
穿心莲内酯体外抗白念珠菌生物膜作用的初步研究 总被引:6,自引:1,他引:5
目的研究穿心莲内酯对体外白念珠菌生物膜的影响。方法采用XTT减低法评价穿心莲内酯对白念珠菌生物膜及其黏附性的影响;镜下观察该药对白念珠菌生物膜的形态学影响;细胞毒性试验检测该药的毒副作用。结果穿心莲内酯对白念珠菌生物膜的SMIC50、SMIC80分别是250、1000μg/ml;1000μg/ml及100μg/ml时对白念珠菌的早期黏附及菌丝生长有抑制作用;对人细胞毒性较弱。结论穿心莲内酯对体外白念珠菌生物膜有显著的抑制作用。 相似文献
48.
Na-Na LIN Hong WANG De-Zhu LI Stephen BLACKMORE 《植物学报(英文版)》2005,47(9):1036-1046
The pollen morphology of 28 species and one variety representing eight genera of the subtribe Mutisiinae Less. sensu Bremer (Compositae) was investigated by scanning electron microscopy (SEM) and light microscopy. The pollen grains are usually radically symmetrical, isopolar, and tricolporate. The shape varies from spheroidal to subprolate in equatorial view and is three-lobed circular in polar view. Based on exine sculpturing observed under SEM, the pollen grains can be divided into three types: (i) type Ⅰ, with macrogranulate sculpture; (ii) type Ⅱ, with a finely granulate sculpture; and (iii) type Ⅲ with spiny sculpture. The palynological data showed that the Macroclinidium Maxim. was remarkably distinguished from those of the other seven genera. The variation of pollen characteristics within the Mutisiinae in Asia is little at species level, but it proves some useful information for studying the relationships among genera and it has an important significance in further understanding the evolutionary history of Mutisiinae. 相似文献
49.
Ectopic Expression of the Pttknl Gene Induces Alterations in the Morphology of the Leaves and Flowers in Petunia hybrida Vilm. 总被引:1,自引:0,他引:1
Xin HU Qing-Feng WU Ya-Hong XIE Hong RU Feng XIE Xin-Yu WANG Chong-Ying WAN 《植物学报(英文版)》2005,47(10):1153-1158
A novel knottedl-like homeobox (knox) gene, Pttknl (Populus tremulaxtremuloides knottedl), isolated from the cambial region of hybrid aspen, was introduced into Petunia hybrida Vilm. using the leafdisc method mediated by Agrobacterium. A series of novel phenotypes was observed in transgenic petunia plants, including the formation of ectopic spikes on the adaxial surface of corollas and small petals on the abaxial surface of corollas, fusion of floral organs, shortening of corolla midribs, the formation of tumor-like knots along the midrib on the abaxial surface and serrated lobs of corolla margins, and alterations in petal color; except for changes in the leaves and plant architecture, RT-PCR showed that the Pttknl gene was expressed in the leaves of different petunia transgenic plants, whereas no signal was detected in wild-type plants. The possible function of Pttknl in leaf and flower development is discussed. 相似文献
50.
Mapping of a Wheat Resistance Gene to Yellow Mosaic Disease by Amplified Fragment Length Polymorphism and Simple Sequence Repeat Markers 总被引:3,自引:0,他引:3
Wei-Hua LIU Huan NIE Zhen-Tian HE Xiu-Lan CHEN Yue-Peng HAN Jin-Rong WANG Xin LI Cheng-Gui HAN Jia-Lin YU 《植物学报(英文版)》2005,47(9):1133-1139
Wheat (Triticum aestivum L.) yellow mosaic virus (WYMV) is transmitted by a fungal vector through soil and causes serious wheat yield losses due to yellow mosaic disease, with yellow-streaked leaves and stunted plants. In the present study, the amplified fragment length polymorphisms (AFLP) and simple sequence repeat (SSR) were used to identify the molecular linkages with the resistance gene against WYMV. Bulked segregant analysis was performed with an F2 population derived from the cross of cultivar Ningmai 9 (resistant) × cultivar Yangmai 10 (susceptible). By screening among the resistant or susceptible parents, the F2 pools and the individuals in the F2 population with 64 combined selective AFLP primers (EcoRI/MseI) or 290 reported SSR primers, a polymorphic DNA segment (approximately 120 bp) was amplified using the primer pair E2/M5, and an SSR marker (approximately 180 bp) was located on wheat chromosome 2A using the primer Xgwm328. Analysis with MAPMAKER/Exp Version 3.0b (Whitehead institute for Biomedical Research, Cambridge, MA, USA) indicated that these two markers were dominantly associated with the resistance gene at distances of 5.4 cM or 17.6 cM, respectively. The resistance gene to WYMV derived from Ningmai 9, is temporarily named YmNM, and was mapped to wheat chromosome 2A. 相似文献