银缕梅叶器官的宏观与微观结构及系统意义

银缕梅〔Ｓｈａｎｉｏｄｅｎｄｒｏｎｓｕｂａｅｑｕａｌｅ（Ｃｈａｎｇ）Ｄｅｎｇ,ＷｅｉｅｔＷａｎｇ〕叶表皮毛为星状毛,气孔器为平列式中周缘型,叶缘齿型为弗特吉型,叶肉栅栏组织一层细胞厚,三叶隙三叶迹的节,从茎节到叶之间的维管束呈分离合并分离的变化格局,并且呈续次合并和续次分离发育模式。这些结果进而说明银缕梅属的独立性,也从一个侧面证明它应属于狭义的弗特吉族（Ｆｏｔｈｅｒｇｉｌｅａｅ）。     

鄂西产三种野生葛总黄酮含量的紫外分光光度法测定

鄂西产三种野生葛总黄酮含量的紫外分光光度法测定李石生刘欣邓京振赵守训（中国药科大学天然药物化学教研室,南京２１００３８）Ｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｔｏｔａｌｆｌａｖｏｎｏｉｄｉｎ３ｗｉｌｄｓｐｅｃｉｅｓｏｆＰｕｅｒａｒｉａｆｒｏｍＷｅｓｔＨｕｂ...     

中国刻姬蜂属一新种(膜翅目:姬蜂科)(英文)

刻姬蜂属ArenetraHolmgren隶属于林姬蜂亚科Banchinae缺沟姬蜂族Lissonotini,分布于全北区。目前已知8种：新北区6种,古北区2种。迄今中国尚无记载,故本属为中国新纪录属。本文报道一新种。狭颊刻姬蜂Arenetragenangusta,sp．nov．（图1－3）正模♀,副模1♀,2♂,吉林,通化,1992年6月30日,盛茂领采。本种与古北区的已知种A．Pilosella（Gravenhorst）和A．agrotidisKokujev的主要区别为小翅室具较长的柄（两个已知种无或几乎无柄）;眼颚距狭,其长约为上颚基部宽的0．34倍（A．pilosella的眼颚距大于上颚基部宽）;并胸腹节外侧脊仅基段存在;产卵器直（A.agrotidik并胸腹节外侧脊完整;产卵器弯曲）。     

水稻亚种间杂种小穗败育的细胞学基础

本文对普通栽培稻不同品种类型间杂种小穗败育的细胞学基础及雌性败育的过程进行了研究,结果表明:(1)引起杂种小穗败育的原因有胚囊败育、花粉败育、开花时花药不开裂和雌雄异熟。其中胚囊败育而丧失受精能力是引起低结实率的最重要的因素,开花时花药不开裂和雌雄异熟在一定程度上形成了雌雄性细胞时间和空间的隔离屏障。(2)杂种植株的所有大孢子母细胞都能进行正常的减数分裂,形成四个大孢子,败育主要发生在靠近合点端的功能大孢子分化形成胚囊的早期,有的功能大孢子在进行第一次有丝分裂前便萎缩解体,多数走向败育的功能大孢子能完成一次或二次有丝分裂,形成二核或四核败育胚囊。败育的共同特征是无液泡的分化,细胞质少或退化,在败育胚囊残迹部位,解体的珠心细胞和萎缩的胚囊残渍混杂垛叠。已受精的杂种子房没有观察到胚及胚乳发育的异常。籼粳杂种胚囊败育频率较高。     

INFLUENCE OF ULTRAVIOLET RADIATION ON THE EXPRESSION OF PROLIFERATING CELL NUCLEAR ANTIGEN AND DNA POLYMERASE α IN SKELETONEMA COSTATUM (BACILLARIOPHYCEAE)1

To evaluate the effects of UV radiation on the expression of DNA replication‐related genes in phytoplankton, the mRNA levels of DNA polymerase α and proliferating cell nuclear antigen (PCNA) in a marine diatom, Skeletonema costatum (Greville) Cleve, were studied using the methods of real‐time quantitative PCR. Treating the algal cultures with UVC radiation for 15 min caused severe mortality during the 24‐h period after treatment. A significant amount of thymine dimers was detected in the treated cultures, and the mRNA levels of DNA polymerase α and PCNA increased by as much as 140 and 23 pmol·(g total RNA)^?1, respectively, compared with the control experiments. In contrast, massive cell deaths did not occur in cultures receiving UVA/B radiation, and the formation of thymine dimers was inconspicuous. Also, UVA/B did not enhance the expression levels of DNA polymerase α or PCNA. Based on the calculation of biologically effective UV doses, daily exposure to sunlight may increase the expression of DNA polymerase α or PCNA genes in S. costatum by 12% at sea surface. This level of increase does not seriously affect the value of using these genes as growth indicators, but caution is needed in the extrapolation of this conclusion to all phytoplankton species.     

STUDY ON THE GENETIC VARIATION OF THE COTTON BOLLWORM HELICOVERPA ARMIGERA (HÜBNER) POPULATIONS IN CHINA*

Abstract Population genetic variations of Helicoverpa armigera (Hiibner) over different major cotton growing regions were analyzed by DNA polymorphism amplified with four simple repetitive sequence primers. The results showed that the laboratory population had relatively lower genetic variation than natural populations. The genetic variation between natural populations was not significant and genetic variation existed in the same location from different years, indicating frequent migration among natural cotton bollworm populations. Cluster analysis indicated that individuals from Chaoyang of Liaoning Province (CY), Gaotang of Shandong Province (GT) and Dafeng of Jiangsu Province(DF) were more mixed each other, which suggested that CY population might have higher gene flow with GT and DF populations, especially with GT population. It supports the theory that the cotton bollworm in Northeast China came from Shandong and Hebei Provinces. This result also demonstrated that the molecular makers in this study are sensitive to detect population genetic structure changes.     

Effects of delayed mating and male mating history on longevity and reproductive performance of the rice stem borer, Chilo suppressalis (Walker) (Lep., Pyralidae)

Abstract:  The mating potential, effects of delayed mating and male mating history on longevity and reproductive performance of female rice stem borer (RSB), Chilo suppressalis , were investigated under laboratory conditions. Given the opportunity, RSB males copulated an average of 2.7 times, while females generally mated only once. Females were more severely affected by mating delay than males in terms of female longevity and reproductive performance. With increasing age at mating, females' longevity increased, while oviposition period, fecundity and egg fertility decreased. Mean fecundity and egg fertility of females mated 1 and 7 days after emergence were 251.3% and 99.2%, and 96.2% and 75.5% respectively. Both were reduced significantly when female mating was delayed beyond 4 days after emergence. However, irrespective of the first mating age and different mating history of the males, the results indicated that both did not result in a significant difference in the quality of their contributions to female longevity and reproductive performance. The results obtained in this study are discussed in relation to the potential effect on pheromone control of RSB.     

Comparison of Cultures from Rectoanal-Junction Mucosal Swabs and Feces for Detection of Escherichia coli O157 in Dairy Heifers

Fecal culture for Escherichia coli O157:H7 was compared to rectoanal mucosal swab (RAMS) culture in dairy heifers over a 1-year period. RAMS enrichment culture was as sensitive as fecal culture using immunomagnetic separation (IMS) (P = 0.98, as determined by a chi-square test). RAMS culture is less costly than fecal IMS culture and can yield quantitative data.     

LncRNA SNHG12 promotes tumorigenesis and metastasis in osteosarcoma by upregulating Notch2 by sponging miR-195-5p

Osteosarcoma is the most common primary malignant bone tumor and has a high fatality rate in children and adolescents. Recently, an increasing amount of evidence has demonstrated that lncRNAs have crucial roles in regulating biological characteristics in malignant tumors. Therefore, this research was carried out to uncover the biological function and the potential molecular mechanism of SNHG12 in osteosarcoma. In this study, we found that SNHG12 was significantly upregulated in both osteosarcoma tissues and cell lines and osteosarcoma patients with high levels of SNHG12 tended to have a poor prognosis. We evaluated the biological function of SNHG12 in 143B and U2OS cells and show that the downregulation of SNHG12 suppressed cell proliferation by blocking cell cycle progression at the G0/G1 phase and weakened cell invasion and migration abilities. Dual-luciferase reporter and RIP assays were conducted to confirm that SNHG12 functioned as a ceRNA, modulating the expression of Notch2 by sponging miR-195-5p in osteosarcoma. We further demonstrate that Notch2 played a crucial role in activating the Notch signaling pathway. In conclusion, SNHG12 might serve as a valuable biomarker and prognosis factor in osteosarcoma patients. The SNHG12/miR-195-5p/Notch2-Notch signaling pathway axis might become a novel therapeutic for osteosarcoma.