土耳其斯坦叶螨的生物学特性及其综合防治

叙述新疆棉花上土耳其斯坦叶螨的危害、发生规律,传播、猖獗因素及综合防治技术。     

Ypsilorchis and Ypsilorchidinae,a new genus and a new subtribe of Orchidaceae

A new orchid genus, Ypsilorchis Z. J. Liu, S. C. Chen & L. J. Chen, is established based on Ypsilor-chis fissipetala (Finet) Z. J. Liu, S. C. Chen & L. J. Chen (basionym: Liparis fissipetala Finet). The new genus differs from Liparis and its allies by having two granular-waxy pollinia each with a somewhat elastic caudicle, deeply bilobed petals and strongly crisped-margined leaves with an apical awn to 1 mm long. These features are an indication of its distant relation to the members of the subtribe Liparidinae, and thus a new subtribe, Ypsilor-chidinae Z. J. Liu, S. C. Chen & L. J. Chen, is proposed.     

卷叶锦鸡儿——锦鸡儿属(豆科)一新种

报道了产于蒙古、内蒙古、宁夏和甘肃的锦鸡儿属(豆科)一新种--卷叶锦鸡儿。该种因叶轴全部宿存,荚果里外均被毛,植株垫状而与Caragana tibetica Kom.相近,但因小叶内卷,管状,横切面呈"O"形,翼瓣耳圆钝而不同。     

大蒜芥属一新变种

发表了大蒜芥属一新变种,无毛全叶大蒜芥(Sisymbrium luteum (Maxim.)O. E. Schulz var. glabrum F. Z. Li et Z. Y. Sun.)。     

水苏属一新变种

发表了水苏属一新变种,毛叶水苏(Stachys japonica Miq. var. tomentosa F. Z. Lie Z. Y. Sun)。     

组织培养暗紫贝母的药理作用

以组织培养的暗紫贝母为材料,野生暗紫贝母为对照,用不同溶剂提取,得４个化学组人 生物碱部分,总皂甙部分,水溶性部分和脂溶性部分,并以生药粉为阳性对照进行药效学试验。结果表明：组培贝母与野生贝母有相似的止咳、祛痰作用;总皂甙部分与总生物碱部分均为川贝有效活性成分,ｔ得之间无显著性差异;经ＴＬＣ是乌头总生物碱部分与总皂甙部分无化学成分重叠。     

杉梢小卷蛾生物学特性及其防治

杉梢小卷蛾是福建省杉木的一种重要害虫,该虫在福建闽北一年发生２－３代,以蛹越冬。虫应以生物防治为主,应用芜菁夜蛾线虫北京品质、白僵菌防治,均有良好防治效果,可在生产上推广应用。     

马来西来番荔枝科紫玉盘属(Uvaria Linn.)、杯冠木属(Cyathostemma Griff.)和Ellipeia Hook.f.et Thomson叶的比较解剖学

对紫玉盘属8种,杯冠木属3种和Ellipeia属1种进行了叶的比较研究,以调查不同种之间解剖学的不同点,这对种的鉴别和了解它们的分类学意义可能是有用的.有意义的解剖学特征是末端石细胞,表皮细胞的晶簇,毛状体,在中脉和叶柄的薄壁组织内的短石细胞以及中脉和叶柄横切面的形状.有某些特征仅出现在某些种中,这对种的鉴别是有用的.结果亦显示这三个属的联系十分紧密.     

Chemical and morphological variation of Mediterranean woody evergreen species: Do plants respond to ungulate browsing?

Abstract. Plant defense theories suggest that chemical or structural defences should be maximized when and where browsing is most likely to occur. We tested this hypothesis on four evergreen woody species growing in a Mediterranean area with a high density of ungulates. In this system, levels of browsing are more intense in the winter (due to the lack of annual plants) and young foliage is often preferred. Therefore we predicted that the chemical defences of these species, namely their phenolic content, would vary with leaf age, season and damage intensity. In addition, we tested whether ungulates preferentially selected species containing lower phenolic levels, and also whether browsing induced either chemical or morphological changes in damaged plants. Phenolic levels varied greatly between plant species; ungulates browsed preferentially on the species with the lowest phenolic levels. No difference in phenolic content was found between browsed and unbrowsed trees. Morphological changes in heavily browsed trees included an increase in shoot and leaf density and a net decrease in leaf size. We suggest that for Mediterranean plants, which have evolved under high browsing pressure from large mammals, the production of small leaves and dense shoots in response to browsing might decrease ungulate foraging efficiency and hence reduce the rate of further damage as effectively as high levels of chemical defence.     

Management of a semi‐natural grassland; results from a 15‐year‐old experiment in southern Sweden

Abstract. Vegetation changes in a semi‐natural grassland of wooded meadow type that had been grazed for centuries are described following the introduction of various management regimes: mowing each year, mowing every third year, burning, mechanical removal of woody plants, chemical treatment of woody plants, continuous grazing and abandonment. The experiment was established in southern Sweden in 1972 and has been in progress for 15 years. In 1972, 1980 and 1986 the botanical composition in these plots was investigated in permanent subplots. The study clearly demonstrates that mowing or grazing is necessary to preserve community structure and that mowing is to be preferred in cases where maintaining species richness is of primary concern. Mowing every third year delayed vegetation change and prevented woody species from spreading. Therefore, periodic mowing might be an alternative way to preserve the flora. In contrast, yearly burning does not seem to be a viable management in this type of semi‐natural grassland. To preserve the open landscape regeneration of woody plants has to be prevented. However, in plots where woody plants were removed the typical grassland flora declined. Abandonment resulted in closed forest.