扶芳藤组织培养再生体系的建立

扶芳藤茎段比叶盘易产生不定芽;4种基因型中,圆瓣扶芳藤的不定芽再生频率远远高于其他3种;MS 6-BA 2.0mg·L-1是圆瓣扶芳藤不定芽诱导的最适培养基;低温处理10 d可显著提高不定芽的再生频率;暗培养对扶芳藤再生影响不大;扶芳藤诱导不定芽的最适pH范围在5.8～6.2之间;最适琼脂浓度为0.6%.     

血管生成素在细胞凋亡调节中的作用机制

血管生成素（angiogenin,ANG）是一种核糖核酸酶;最近研究证明,作为一种抗凋亡因子,ANG参与各种抗细胞凋亡过程. ANG对内源性及外源性相关信号途径中的重要分子,如Bcl-2抗凋亡蛋白具有调节作用.此外,ANG对内、外部信号途径中的重要环节--p53依赖的凋亡也具有调节作用.     

三种种植方式对土壤微生物群落组成的影响

土壤微生物是表征土壤质量变化的敏感指标之一。借助长期定位试验, 采用磷脂脂肪酸分析方法研究了3种种植方式(玉米(Zea mays)连作、玉米非连作和撂荒)对土壤微生物群落组成的影响。结果表明, 在不同的种植方式下, 土壤微生物群落组成有明显的差异。玉米连作的土壤中总磷脂脂肪酸和细菌磷脂脂肪酸含量最低, 分别为33.12 nmol·g^-1和18.09 nmol·g^-1。非连作的土壤真菌磷脂脂肪酸和真菌/细菌分别为0.61 nmol·g^-1和3.06%, 显著低于撂荒和连作(p < 0.05), 非连作方式下, 革兰氏阳性细菌/革兰氏阴性细菌增大。撂荒土壤的总磷脂脂肪酸和细菌磷脂脂肪酸分别为42.98和24.68 nmol·g^-1, 高于耕作处理。 同时, 在撂荒方式下, 革兰氏阳性细菌和革兰氏阴性细菌的含量增加, 革兰氏阳性细菌/革兰氏阴性细菌降低。主成分分析结果表明: 耕作处理(玉米连作和非连作)分布第一主成分负方向上, 第一主成分得分系数分别为-2.48和-1.84; 撂荒分布第一主成分正方向上, 第一主成分得分系数为2.31, 与连作和非连作差异显著(p < 0.05)。冗余分析(RDA)表明: 土壤pH、总氮、有效磷和土壤>0.25 mm水稳性团聚体含量与磷脂脂肪酸呈正相关, 并且土壤pH和土壤>0.25 mm水稳性团聚体含量对土壤微生物群落的影响最大。     

青菜的高效再生和农杆菌介导B.t.及CpTI基因的转化

分别对培养基中适宜的激素组成和AgNO3 添加浓度进行研究 ,建立了青菜下胚轴和子叶外植体的高效再生系统 ,青菜品种“矮抗青”的最高芽分化频率下胚轴可达 6 5 % ,子叶为 5 2 %左右。在此基础上 ,对影响转化频率的不同因素进行了探讨 ,共获 94株卡那霉素抗性植株。对转基因植株总DNA的Southernblot ting分析证明 ,B .t .基因和CpTI基因已整合到青菜植株的细胞核基因组中。经过抗虫性筛选试验 ,从转基因植株的T3 代筛选到 7个转B .t.基因的抗虫纯合株系和 5个转CpTI基因的抗虫纯合株系 ,并进入田间小区青菜抗虫新品种试验     

Development of Ovules and Embryo sacs in Ostrya virginiana (Betulaceae) and Its Systematic Significance

The development of ovules and embryo sacs in Ostrya virginiana was studied for the first time. Most ovaries had two ovules which were anatropous, unitegmic and crassinucellate. The ovule usually possessed several archesporial ceils which divided periclinally into the upper parietal cell and the lower sporogenous cell. The sporogenous cell functioned directly as megaspore mother cell. The tetrad of megaspores was linear in arrangement, and every megaspore might be functional. One ovule often contained 2- 6 embryo sacs and the embryo sac belongs to Polygonum type. It can be concluded from the present data that all ovules among the genera of the Betulaceae are unitegrnic. There are more groups with the phenomenon of multiple embryo sacs in anemophic plants such as Betulaceae, Casuarinaceae, Graminae, Jnglandaceae, Myricaceae, Simaroubaceae, Ulmaceae, than in entomophilous plants. Multiple embryo sacs also occur among some parasitic plants and saprophytes, e.g. Orobanchaceae, Cassytha in Lauraceae, Cuscuta in Convolvulaceae and Utricularia in Lentibulariaceae. It may be inferred that the characteristic of multiple embryo sacs be an evolutionary adaptation of those plants with lower pollination rate to increase the rate of fertilization. Finally, a comparison of embryological characters among the genera of the Betulaceae shows that the family is of a number of common embryological characters, such as multicellular archesporium, multiple embryo sacs in one ovule, and a long interval between pollination and fertilization. The diversity and systematic significance of several embryological characters among the “higher” hamamelid families are also discussed. It is still hard to explain the phy-logenetic relationships among those families clearly only with.     

花生胚乳细胞化的超微结构观察

花生（ＡｒａｃｈｉｓｈｙｐｏｇｅａｅＬ．）心形胚期的胚乳游离核多瓣裂,或具长尾状结构。胚乳细胞质内有大量线粒体、质体、高尔基体、小泡及少量内质网。中央细胞壁有壁内突。球胚及心形胚期常见胚乳瘤。心形胚晚期,胚乳开始细胞化,胚乳细胞壁形成有３种方式,分别存在于不同的胚珠中：（１）从胚囊壁产生自由生长壁形成初始垂周壁,具有明显的电子密度深的中层,其生长主要靠末端的高尔基体小泡及内质网囊泡的融合。两相邻的自由生长壁末端或其分枝末端相连形成胚乳细胞。（２）核有丝分裂后产生细胞板,细胞板向外扩展并可分枝。间期的非姊妹核间也观察到形成了细胞板。小泡与微管参与细胞板的扩展,高尔基体和内质网是小泡的主要来源。细胞板的扩展末端相互连接,形成胚乳细胞的前身。小泡继续加入细胞板的组成,以后形成胚乳细胞壁。（３）胚乳细胞质中,出现一些比较大的不规则形的片段性泡状结构,它们可能来源于高尔基体小泡,这些片段性泡状结构随机相连形成细胞壁,未见微管参与。胚乳细胞外切向壁及经向壁上有壁内突。     

Chinese species of genus Notopygus Holmgren (Hymenoptera,Ichneumonidae, Ctenopelmatinae) with description of a new species

A new species, Notopygus longiventris Sun & Sheng, sp. n., collected from Benxi County, Liaoning Province, China, and N. emarginatus Holmgren, 1857, reared from Neurotoma sibirica Gussakovskij (Hymenoptera, Pamphiliidae) from Haicheng, Liaoning Province, are reported. The new species is placed within existing key to species.     

A new species of Xorides Latreille (Hymenoptera,Ichneumonidae, Xoridinae) parasitizing Pterolophia alternata (Coleoptera,Cerambycidae) in? Robinia?pseudoacacia

A new species is described, Xorides benxicus Sheng, sp. n., reared from the cerambycid twig-boring pest of Robinia pseudoacacia Linnaeus, Pterolophia alternata Gressitt, 1938, in Benxi County, Liaoning Province, China. A key is given to the species similar to Xorides benxicus Sheng, namely Xorides asiasius Sheng & Hilszczański, 2009, Xorides cinnabarius Sheng & Hilszczański, 2009 and Xorides sapporensis (Uchida, 1928).