石蝴蝶属八种植物的染色体数目报道

观察了苦苣苔科石蝴蝶属(Petrocosmea)8种植物的染色体.发现它们的染色均属小型染色体,数目一致,皆为2n=34.     

香溪河水系附石藻类的时空动态

香溪河系长江三峡水库湖北库区内第一大支流.对香溪河2005年7月—2006年6月干流及主要支流上12个样点的附石藻类进行调查，共观察到藻类218种，其中硅藻183种、绿藻24种、蓝藻10种、黄藻1种，硅藻门的线形曲壳藻为绝对优势种.其物种丰富度和Shannon-Wiener多样性指数时空动态差异显著（或接近显著），总平均值分别为32和154.附石藻类密度和叶绿素a含量年总平均值分别为8.75×10.9 cells·m^-2和14.62 mg·m^-2.不同样点的藻类密度和叶绿素a含量差异显著，其中古夫河支流最高，九冲河支流最低，两者相差一个数量级; 不同季节附石藻类密度和叶绿素a含量差异不显著(P>0.05)，但均表现出冬春季高、夏秋季低的趋势.附石藻类密度及叶绿素a含量与海拔及水流流速呈显著负相关，而与总氮呈正相关.     

Effects of long-term flooding on respiratory metabolism of Taxodium ‘Zhongshansha 118’ seedlings

Aims Taxodium ‘Zhongshansha’ had a strong submergence tolerance, but the biological mechanism is not clearly defined. The respiratory metabolism for the tolerance of Taxodium ‘Zhongshansha 118’ ((Taxodium distichum × Taxodium mucronatum) × Taxodium mucronatum) to long-term flooding was investigated through the measuring and analyzing the changes in root starch and soluble sugar as well as the contents of anaerobic respiration enzymes, including lactic dehydrogenase (LDH), ethanol dehydrogenase (ADH) and pyruvate decarboxylase (PDC)), in the ‘Zhongshansha 118’ seedling. The biomass and activities of the seedling roots were also measured and analyzed.Methods 24 1-year Taxodium ‘Zhongshansha 118’ seedlings were randomly and equally divided into four groups and each group experienced one of four different levels of flooding (i.e., no flooding, waterlogging, partial submergence, deep submergence) from August 8 to November 8, 2014.Important findings The results showed that the contents of the anaerobic respiration enzymes in the seedling roots and leaves are increasing with the levels of severity of flooding, which indicated the roots and leaves adapt to long-term flooding by reinforcing their anaerobic respiration and activities of ADH that were higher than LDH for roots and leaves used in alcoholic fermentation mainly. The activities of anaerobic respiration enzymes in leaves were higher than that in roots, while leaves were more sensitive to flooding. The starch and soluble sugar in roots and leaves had similar trend with anaerobic respiration enzymes. However, roots starch was higher than leaves where soluble sugar was lower than roots. The higher content of starch were the important reason of strong submergence tolerance, and we consider the strategy to fit into long-term flooding is patience type. The paper demonstrate Taxodium ‘Zhongshansha 118’ have the physiological and the morphological properties to adapt to long-term flooding, including aerial root and basal part of stem expanded and the outer wall of the root lignified to protect the roots from flooding.     

药用植物蛇足石杉研究新进展

蛇足石杉[Huperzia serrata（Thunb．）Trey．]是石杉科石杉属多年生小型草本植物，土生、附生或生于苔藓层中，喜阴凉潮湿环境。蛇足石杉含石杉碱甲，为目前治疗老年痴呆等疾病的特效药。对蛇足石杉的分类学、生物学特性（形态学、生态学、生理学与共生真菌研究）、繁殖与栽培、药用成分及含量测定等方面的研究新进展进行综述。并对其应用与保护前景进行展望。     

牙形石Histiodella Hass 四个种的讨论及地层对比意义

作者描述了产自塔里木盆地的HistiodellaHass的四个种,并探讨了它们与中国北方和北美中大陆暖水型牙形石及中国南方和北大西洋冷水型牙形石的对比关系。认为Histiodellasinuosa带对比北美中大陆牙形石动物群3的下部、中国南方Amorphognathusvariabilis带下部和中国北方Aurilobodusleptosomatus-Loxodusdissectus带下部。Histiodellaholodentata带下部相当于中国北方Aurilobodusleptosomatus-Loxodusdissectus带中部或中国南方的Amorphognathusvariabilis带至Eoplacognathussuecicus带的下部。Histiodellakristinae带对比北大西洋区的Eoplacognathussuecicus带中上部和中国北方的Tangshanodustangshanensis带。Histiodellabellburnensis带对比北大西洋区的Eoplacognathussuecicus带的上部到Eoplacognathusfoliaceus带下部。HistiodellaHass与北大西洋区和中国北方区典型牙形石的共同出现可以作为一个桥梁,建立起北美中大陆、北大西洋、塔里木盆地及华北地区牙形石的对比关系。     

天胡荽属三种药用植物果实的形态组织结构特征

对天胡荽属3种药用植物果实进行了形态组织学方面的研究,发现三者中果皮内侧石细胞的存在情况则随品种的不同而不同,结果可作为这三种植物的品种鉴别特征,同时为伞形科植物学研究提供新的内容.     

杉木优良变异类型——罗田垂枝杉生物学特性研究

罗田垂枝杉是20世纪70年代中期在湖北省罗田县发现的杉木自然变异类型,在与黄枝杉比较的基础上,对罗田垂枝杉的形态变异特征和生物学特性进行了深入的调查研究,其形态特征与其它杉木类型的主要区别是：2～3年生的侧枝自然下垂,6～7年生的老枝自然脱落,树冠窄小,是具有遗传改良品质和较高利用价值的种质资源。     

越南苦苣苔科植物四新记录种

报道了4个苦苣苔科(Gesneriaceae)植物在越南的分布新记录,其中1种为半蒴苣苔属(Hemiboea)的红苞半蒴苣苔(H.rubribracteata),2种为报春苣苔属(Primulina Hance)的文采报春苣苔(P.wentsaii)和疏花报春苣苔(P.laxi flora),还有1种为吊石苣苔属(Lysionotus)的桂黔吊石苣苔(L.aesch ynanthoides)。文中列出了每个种的标本引证和地理分布情况。     

不同类型森林石灰土的团聚体组成及其有机碳分布特征

选取中国西南喀斯特石灰土人工林、次生林、原生林3个主要森林类型的6个代表性群落,建立18个20m×20m的样方,按梅花型5点法采集各样方的原状土壤,基于团聚体的干湿筛2种分组方法,研究不同类型森林石灰土机械性、水稳性团聚体组成及全土、各粒级团聚体的有机碳分布特征。结果显示:(1)3类森林石灰土干湿筛团聚体均以>2mm粒径为主,分别为67.93%～81.24%和30.49%～76.81%,1～10mm粒径的干湿筛优势团聚体分别高达78.18%～88.67%和43.41%～84.00%。(2)团聚体的整体稳定性很好,干湿筛平均重量直径(MWD)为4.82～5.77和0.75～2.13,平均几何直径(GMD)为2.87～4.17和1.45～2.85;>0.25mm和>2mm粒径的团聚体破坏率(PAD)分别仅为6.15～20.91和2.04～52.79。(3)石灰土的有机碳含量很高,全土和干、湿筛团聚体的有机碳含量分别为17.28～58.85、19.12～91.47、17.16～78.86g/kg,其中干筛以<2mm粒径团聚体的有机碳含量较高,湿筛反之,但干湿筛均以>2mm粒径团聚体的有机碳贮量最高。研究表明,中国西南喀斯特石灰土林区土壤沿人工林、次生林、原生林土壤扰动递减梯度,石灰土的团聚化作用越来越强,稳定性越来越好,有机碳含量也越来越丰富。