基于核基因的黄绿卷毛菇系统发育与谱系地理学分析

黄绿卷毛菇(Floccularia luteovirens)隶属于伞菌目(Agaricales)口蘑科(Tricholomataceae)是一种主要分布在青藏高原的产子实体的外生菌根真菌。本研究以青藏高原黄绿卷毛菇(F.luteovirens)的23个野生居群,404个个体为研究对象,利用rDNA三个片段(ITS+5.8 s,IGS-1以及LSU)研究了青藏高原黄绿卷毛菇种內的系统发育关系。研究表明:联合序列共获得15种基因型,基因型多样性(h)的范围从0.374 3(MD)到1.000 0(DR),平均值为0.723 3。歧点分布分析走势呈现单峰曲线,表明黄绿卷毛菇居群近期经历过扩张过程。对黄绿卷毛菇基因型变异的分布模式进行验证,得到NST>GST(p<0.05),表明黄绿卷毛菇基因型之间具有显著地分子系统地理结构。分子变异分析(AMOVA)表明,黄绿卷毛菇的遗传变异主要存在于居群内部(79.17%)。基于MP树和ML树的研究发现基因型H3、H4、H5、H15首先和其他基因型分开,而在贝叶斯分析中则不存在这一分支。没有一个居群拥有特有的基因型,但是就基因型多样性地域分布格局来看,各个基因型的多样性由北向南呈明显的减少趋势。结合软件NETWORK的分析可以知道,几种主要分布在阿尼玛卿山以南的基因型都位于网路结构的边缘,说明这几种基因型是较晚形成的。本研究是对之前利用蛋白质编码基因研究的很好地补充。     

基于LSU和ITS的青藏高原黄绿卷毛菇种群遗传多样性分析

为研究黄绿卷毛菇群体遗传结构,以青海、西藏、四川3个省份的10个地理群共91个样本黄绿卷毛菇为实验材料,采用分子生物学方法测定和分析所有样本的LSU和ITS序列。结果显示:1 995bp的LSU和ITS基因序列共有8个变异位点,得到20个基因型。单倍型多样性指数(Hd)和核苷酸多样性指数(pi)分别为0.538±0.026和0.00029±0.00002;青海玉树和青海兴海的遗传多样性指数最高。分子变异分析结果表明黄绿卷毛菇群体遗传变异主要来自种群内(75.70%),种群间遗传分化较大。系统进化树结果也表明,10个地理群分成2个支系,黄绿卷毛菇群体存在明显的地理结构。中性检测结果进一步证实,黄绿卷毛菇群体有着复杂的群体历史,曾发生过种群数量扩张,近期种群数量正在衰减。     

西藏黄绿卷毛菇生境土壤微生物群落组成

牧草外生菌根菌黄绿卷毛菇Floccularia luteovirens具有较高的生态和经济价值,其生境微生物对其菌丝生长、菌根化和子实体形成具有促进作用。本研究利用高通量测序技术对西藏黄绿卷毛菇菌窝土壤及其周围无菇土壤微生物群落组成进行分析,挖掘促进黄绿卷毛菇生长的有益微生物资源。结果显示,西藏黄绿卷毛菇生境土壤细菌隶属于17门22纲116目161科227属,其中酸杆菌门、变形菌门、拟杆菌门和疣微菌门累计比例高达81.75%;生境土壤真菌隶属于5门17纲34目55科61属,子囊菌门和担子菌门累计比例高达80.89%。对比周围无菇土壤的微生物群落,促进黄绿卷毛菇生长的潜在细菌类群为Flavisolibacter、黄杆菌属Flavobacterium、芽单胞菌属Gemmatimonas、Haliangium、赛格特杆菌Segetibacter和鞘氨醇单胞菌属Sphingomonas;促进黄绿卷毛菇生长的潜在真菌类群为斜盖伞属Clitopilus、丝膜菌属Cortinarius、被孢霉属Mortierella和毛霉属Mucor。土壤微生物促进黄绿卷毛菇生长繁殖的机制有待进一步研究。     

黄绿卷毛菇生境中矮嵩草内生真菌多样性比较研究

为研究黄绿卷毛菇生境中矮嵩草的内生真菌多样性,本研究结合传统分离培养法和宏基因组法对矮嵩草内生真菌的多样性进行比较研究。结果显示:传统法在矮嵩草共分离鉴定得到66株内生真菌均属于子囊菌门(Ascomycota),分类到7目,分别为格孢腔目(Pleosporales)、炭角菌目(Xylariales)、散囊菌目(Eurotiales)、柔膜菌目(Helotiales)、肉座菌目(Hypocreales)、毛霉菌目(Mucorales)、Glomerellales,优势种群为Stagonospora bicolor;根的多样性指数,丰富度指数,均匀度指数分别为1.63、1.56、0.82;未分离到黄绿卷毛菇;宏基因组法检测出587种内生真菌,子囊菌门(Ascomycota)占77.21%、担子菌门(Basidiomycota)占16.21%,剩下的6.58%为unclassified真菌,优势种群为Fusarium sp,多样性指数,丰富度指数,均匀度指数分别为3.13、39.08、0.48;检测到黄绿卷毛菇,相对丰度为11.39;比较两种方法,黄绿卷毛菇生境的矮嵩草植物中,蕴含着丰富的内生真菌资源,黄绿卷毛菇为优势内生真菌种群之一。该研究首次证明黄绿卷毛菇为嵩草属的内生真菌,是研究黄绿卷毛菇的营养类型及其与植物间的互作关系的新突破。     

基于MaxEnt模型的当归全球生态适宜区和生态特征研究

研究药用植物当归在全球范围内的生态适宜区和生态特征,根据109个当归样本点和37个生态因子,利用最大信息熵模型(Max Ent)和地理信息系统(Geographic information System,GIS)对其进行全球适宜性区划。结果表明,当归生态适宜区主要集中在北纬20—50°范围内的北美洲、欧洲、亚洲和南纬15—35°范围内的南美洲和非洲,共约593.07万km~2。其中生态相似度最高的区域主要分布在中国甘肃省南部、四川省、西藏自治区东部、云南省北部、贵州省、陕西省西南部等地区,可见中国十分适合当归的种植,是当归的主产区。影响当归地理分布的主要气候因子适宜值范围分别为:最暖季降水量为300—700 mm,最冷季平均温为-3—7℃,降水的季节性数值为70—98;影响当归地理分布的主要土壤因子适宜值范围分别为:碳酸钙含量为50%—60%,粘土比重为17%—24%。研究结果为当归人工引种栽培及精细化种植管理提供参考。     

我国甜菜夜蛾间歇性暴发频度的大尺度地理差异及其成因分析

【目的】为探索我国甜菜夜蛾Spodoptera exigua(Hübner)间歇性大暴发频度的大尺度地理差异及其成因,作者研究和分析了我国1956—2008年52年间共发生的121次甜菜夜蛾大暴发频次地理分布的行政区域特征、纬度特征和经度特征。【方法】首先查阅和整理我国历代以来有关甜菜夜蛾记载和研究的文献,并按时间序列方式进行归纳和总结,得出中国1956—2008年52年间共发生甜菜夜蛾大暴发频次为121年次,然后分别按中国省级行政区域、纬度分级区域和经度分级区域进行重新整理分析,在此基础上,进一步细分出中国不同省区及不同经纬度地区甜菜夜蛾有暴发记录的历年总频次数,然后进行统计分析。【结果】分析结果表明:按省级行政区域进行统计,中国有17省(直辖市)有甜菜夜蛾暴发的记录;按暴发频次多少可分为低频暴发区(记录1~4次的共有8省市,即天津1、北京1、海南1、湖南1、云南2、广西3、辽宁3、福建3)、中频暴发区(记录5~9次的共有5省市,即湖北5、安徽7、上海8、江西8、陕西8,占总频次的29.8%)和高频暴发区(记录10次以上的4省市,即山东10、河南13、浙江13、江苏34,占总频次的58%)。按经纬度值进行统计,中国甜菜夜蛾有暴发记录的纬度范围为21.44°~41.97°N,即从中国南部的福建莆田至北部的辽宁抚顺都有甜菜夜蛾暴发的记录,经度范围为107.09°~123.97°E,即从中国西部的陕西关中至东部的辽宁抚顺都有甜菜夜蛾暴发的记录。而暴发最频繁的纬度范围是28°~38°N,约占总频次的89.3%;暴发最频繁的经度范围是113°~121°E,约占总频次的81.8%。【结论】中国甜菜夜蛾间歇性暴发区以华北平原和长江中下游平原地区为主,暴发寄主以蔬菜和棉花为主,暴发季节以7—10月为主。甜菜夜蛾间歇性高频暴发区,其地理特征主要为低海拔地区,即平均海拔低于500 m(也有极少部分发生在平均海拔为1 000~2 000 m之间的盆地);其气候特征主要为暖温带3 400℃≤活动积温≤4 500℃及亚热带地区4 500℃≤活动积温≤8 000℃、湿润(年降水量≥800 mm)及半湿润地区(400≤年降水量≤800 mm)和亚热带及温带季风气候区(该两个气候区的共同特点是夏季高温多雨,冬季低温少雨或寒冷干燥)。     

黄绿卷毛菇水提物对糖尿病大鼠机体抗氧化及抗炎作用初探

氧化应激被认为是糖尿病、肿瘤、肝病等多种疾病发生的一个关键危险因素。通过抗氧化剂阻断或延缓氧化反应和炎症过程,有望成为预防或治疗糖尿病的一种有效的干预手段。黄绿卷毛菇Floccularia luteovirens又名黄绿蜜环菌,是青藏高原特有的一种稀有珍贵的食药用菌,其子实体具有抗肿瘤、抗炎、抗氧化等诸多药理作用。在本研究中,我们初步探究了黄绿卷毛菇水提物（water extract of Floccularia luteoviren,FLW）对Ⅱ型糖尿病大鼠机体抗氧化和抗炎作用。二甲双胍及FLW连续灌胃给药8周,结果表明,FLW可以促进外源性葡萄糖的消耗,明显改善糖尿病大鼠的口服糖耐量;显著提高血清中SOD水平,显著降低血清中MDA及炎症因子IL-1β、TNF-α、IL-6的释放。综上所述,FLW表现出较强的抗氧化和抗炎活性,对Ⅱ型糖尿病大鼠机体氧化应激和炎症具有良好的改善作用。     

1982—2015年青藏高原植被变化的主导环境因子

近几十年中随着全球气候环境变化,青藏高原处于变暖变湿过程之中,植被生长发生了显著变化。基于卫星遥感归一化植被指数(NDVI),采用增强回归树模型(BRT)定量分析了1982—2015年影响青藏高原植被生长变化的主要环境因子的相对重要性。结果表明：(1)整个青藏高原生长季(6—9月份)空间平均NDVI和降水呈上升趋势(1.265×10^-4 a^-1和0.746 mm/a,P>0.05);温度和土壤湿度呈现显著增加趋势(0.048℃/a和3.954×10^-4 a^-1,P<0.01);向下短波辐射显著减小(-0.070 W m^-2 a^-1,P<0.01)。(2)青藏高原34.0%地区NDVI表现出显著增加趋势,主要分布在青藏高原北部大部分地区和西部部分区域;9.2%地区NDVI呈显著减小趋势,主要位于青藏高原东部地区。(3)土壤湿度、年均温、年降水和向下短波辐射分别解释了生长季NDVI变化的42%,19%,10%和9%。(4)土壤湿度、年均温、年...     

基于RAD测序技术的黄绿卷毛菇(Floccularia luteovirens)微卫星引物的开发

黄绿卷毛菇(Floccularia luteovirens)是广泛分布于青藏高原高寒草甸的一种重要的可食用的菌根真菌。先前的研究利用EST-SSR引物已经对该物种的遗传多样性及群落结构进行了研究,但研究表明EST-SSR位点多态性较低,因此想要进一步探讨形成现有遗传分布格局的机制(该物种小尺度空间范围内基株的密度及大小)需要重新开发具有更高多态性的基于核基因的微卫星位点。本研究利用RAD测序技术使用直接测序分析的方法重新开发了12对具有多态性的引物。测序结果去接头拼装后共获得46 036条重叠群。在这些序列当中共扫描到342条含有重复单元的序列,在这当中70.47%为三碱基重复(241),8.19%为二碱基重复(28)。随机选取48对检测,12对具有多态性且测序结果良好,基于3个居群63个个体的遗传多样性研究显示,所有样品中共获得60个单倍型,每个位点的单倍型数量介于2 (GSSR26L)至9 (GSSR7L,GSSR11L)之间。Gst值介于-0.03(GSSR46L)至0.28(GSSR6L)之间、Fst值介于-0.03(GSSR33L)至0.42(GSSR6L)之间。在引物GSSR47L扩增测序中发现,其扩增出的片段不仅具有重复单元数量的变化,重复单元本身也存在突变的现象,这是之前使用聚丙烯凝胶电泳所检测不到的。本研究获得的微卫星引物将为接下来小尺度空间下研究黄绿卷毛菇基株的密度、大小及动态变化提供有力的支持。     

中国亚热带地区4种极危冷杉属植物的地理分布特征及其与气候的关系

通过野外实地调查和文献调研, 分析4种极危冷杉属(Abies)植物的地理分布现状和特征, 构建其分布区的气候数据库, 采用国际上常用的研究植被与气候关系的指标和方法, 定量分析冷杉属地理分布与水热条件的关系, 并通过因子分析方法确定影响冷杉属地理分布的限制性气候因子。结果表明: 1)百山祖冷杉(Abies beshanzuensis)、梵净山冷杉(A. fanjingshanensis)、元宝山冷杉(A. yuanbaoshanensis)和资源冷杉(A. beshanzuensis var. ziyuanensis)零星分布于我国亚热带地区, 水平分布范围为25°25′-27°55′ N, 108°42′-119°12′ E , 分布范围狭窄; 垂直分布范围为1363-2390 m, 均分布于山体上部。海拔上限高度随着经度的减小而增加。2)整个分布区的气温较低, 年平均气温为7.4-11.2 ℃; 降水较为充沛, 年降水量为1265.4-1945.7 mm, 其中生长季降水量占74.78%; 湿度较大, 年相对湿度为77%-86%。气候指标范围狭窄, 表明对水热条件要求很高。分布区寒冷指数较低, 限制其垂直向下扩散, 呈现局限分布于山体上部的现状。3) 4种冷杉各分布区的气候条件基本相近, 梵净山冷杉分布区气温相对偏低, 元宝山冷杉分布区湿度相对偏大。4) 3个气候因子对这4种冷杉的地理分布影响较大, 其作用排序为: 低温因子>极端低温因子>湿度因子。在全球气候变暖的大背景下, 这4种冷杉自然分布区的适宜生境将进一步缩小, 直至物种灭绝, 急需开展迁地保护工作。     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Analysis of twin of eyeless regulation during early embryogenesis in Drosophila melanogaster

The Drosophila Pax6 homolog twin of eyeless (toy) is so far the first zygotically expressed gene involved in eye morphogenesis in Drosophila. The study of its expression during embryogenesis is therefore informative of the initial events of eye development in Drosophila. We have analyzed how the initial expression domain of toy at cellular blastoderm is regulated. We show that the three maternal patterning systems active in the cephalic region (the anterior, terminal and dorsal-ventral systems) cooperate with zygotically activated gap genes to shape the initial expression domain of toy. Whereas Bicoid, Dorsal and Torso signaling synergistically act as activators, Hunchback, Knirps and Decapentaplegic act as repressors.     

Host plants of someRhinanthoideae (Scrophulariaceae) of eastern North America

Twenty three species in 11 genera were examined in the field to determine hosts. OnlyStriga asiatica andSeymeria cassioides have a narrow host range being restricted to grasses and pines, respectively. These are the only species which cause pronounced and sometimes serious host damage. The other species attach to a great diversity of hosts.     

Apoptotic Regulation of Caspase Activity

Intracellular cysteine aspartate-specific proteases (caspases) play both signaling and effector roles in realizing the program of cell death. Caspases function as proteolytic cascades unique for each cell type and signal triggering apoptosis. All parts of the proteolytic cascades are duplicated and controlled by feedback signals. Amplification cycles between pairs of caspases (the third and the sixth, the ninth and the third, the twelfth and the sixth, and others) help multiply the initial apoptotic signal. The presence of physiological inhibitors of apoptosis that directly interact with caspases creates a multilevel regulatory network of apoptosis in cell. The caspase proteolytic cascades are also regulated by sphingolipid secondary messengers, among them ceramide, sphingosine, and their phosphates. Moreover, an association of the caspase signaling with ubiquitin-dependent proteolysis is shown in cells. In particular, the use of extracellular activators and inhibitors of caspases allows irreversible activation of apoptosis in tumor cells or the prevention of apoptosis in cortical neurons under neurodegenerative diseases.     

广西青藓科分类学修订

通过对采自广西24个县(市)的1 147份青藓科植物标本的逐一鉴定及相关文献的查阅,确认有广西青藓科植物11属、44种,其中包括广西青藓科植物新记录属1属,即拟异叶藓属(Pseudokindbergia),新记录种7种,分别为匐枝青藓(Brachythecium procumbens)、阔叶尖喙藓(Oxyrrhynchium latifolium)、泛生尖喙藓(O. vagans)、拟异叶藓(Pseudokindbergia dumosa)、华东细喙藓(Rhynchostegiella sinensis)、长肋拟青藓(Sciurohypnum populeum)和弯叶拟青藓(S. reflexum)。该文提供了修订后的广西青藓科植物名录,并对其中的新记录属、种的主要形态学识别特征、生境和地理分布等进行了详细描述。     

The effect of cyanobacteria and azolla on the performance of rice under different levels of fertilizer nitrogen

Cyanobacteria and/or azolla were inoculated, with urea at 0, 72 or 144 kg N/ha, in plots in which azolla-free Indica rice var. IR 28 was grown. Productive tillers, yield and nitrogen contents of grain and straw positively responded to inoculation with cyanobacteria or azolla, even with fertilizer-N up to 144 kg N/ha. Inoculation improved colonization by cyanobacteria. Azolla were superior to the asymbiotic cyanobacteria in enhancing rice performance. Urea at a rate of 72 kg N/ha was found to support the best colonizations when applied with cyanobacteria or azolla or, to give maximum rice yields, both inoculants.     

Evaluation of antiprotozoal and antimycobacterial activities of the resin glycosides and the other metabolites of Scrophularia cryptophila

Resin glycosides are secondary metabolites exclusive to the convolvulaceous plants. In this study, crypthophilic acids A–C (1–3), the first resin glycosides occurring in another family (Scrophulariaceae), and the other constituents of Scrophularia cryptophila were examined for in vitro antiprotozoal and antimycobacterial potentials. Except for crypthophilic acid B (2), all tested compounds exhibited growth-inhibitory effect against Trypanosoma brucei rhodesiense, with l-tryptophan (6) and buddlejasaponin III (7) being the most potent ones (IC₅₀'s 4.1 and 9.7 μg/ml). In contrast, the activity towards Trypanosoma cruzi was poor, and only crypthophilic acid C (3), 6 and 7 were trypanocidal at concentrations above 40 μg/ml. With the exception of 2 and 6, all compounds were active against Leishmania donovani. Harpagide (4) and 3 emerged as the best leishmanicidal agents (IC₅₀'s 2.0 and 5.8 μg/ml). Only compounds 3, 6 and 7 showed antimalarial activity against Plasmodium falciparum with IC₅₀ values of 4.2, 16.6 and 22.4 μg/ml. Overall the best and broadest spectrum activity was presented by compounds 3 and 7, as they inhibited all four parasitic protozoa. None of the isolates had significant activity against Mycobacterium tuberculosis (MICs >100 μg/ml) or were toxic towards mammalian (L6) cells. This is the first report of antiprotozoal activity for natural resin glycosides, as well as for harpagide (4), acetylharpagide (5), tryptophan (6) and buddlejasaponin III (7).