太行山片麻岩区栓皮栎外生菌根真菌多样性

以太行山片麻岩区栓皮栎Quercus variabilis为研究对象,利用形态学、常规测序与Illumina MiSeq高通量测序相结合的方法,调查并鉴定了与其共生的外生菌根真菌。最终共划分出18种栓皮栎外生菌根形态类型。高通量测序得到394个外生菌根真菌OTUs（operational taxonomic units）,隶属于11目23科30属。其中栓皮栎外生菌根核心菌群（core microbiome）共9属17个OTUs,总相对多度达65.16%。样地1与样地2中样本的多样性指数无明显差异,但非度量多维尺度分析（NMDS）表明核心菌群在2个样地中的分布不同,其中红菇属Russula、牛肝菌属Boletus、粉孢牛肝菌属Tylopilus、硬皮地星属Astraeus主要分布于位于阳坡的样地1,而空团菌属Cenococcum、小球孢盘菌属Sphaerosporella、锁瑚菌属Clavulina、丝盖伞属Inocybe主要分布于位于阴坡的样地2,毛革菌属Tomentella在两个样地的分布相似。     

三种稻飞虱成虫体内酵母类共生菌的形态差异

试验采用冷冻切片技术结合显微摄像系统观察法研究了酵母类共生菌在3种稻飞虱成虫体内的存在状态、形态特性以及种类和组成.光学显微镜观察证实,3种稻飞虱成虫的头部和胸部均未观察到共生菌,在其腹部脂肪体中有大量酵母类共生菌,且以出芽进行无性繁殖,并伴有菌胞的出现.3种稻飞虱成虫体内共生菌的形态和组成明显不同.其中,褐飞虱体内的共生菌个体较大,以梭形、杆状和卵形为主,分别占共生菌总数的30.7%、53.5%和15.1%;灰飞虱和白背飞虱体内的共生菌个体较小,以卵形为主,分别占共生菌总数的93.4%和94.7%.此外,褐飞虱成虫体内的各类共生菌都显著大于灰飞虱和白背飞虱成虫体内的同种类型个体,且灰飞虱和白背飞虱体内的同种共生菌个体大小之间也存在一定差异.     

羊柴叶形态结构的地域分异特征及其与生态因子间的关系

为探讨沙旱生植物的形态及组织结构对地域分异的响应,揭示植物形态、结构的地域分异规律。该研究以呼伦贝尔沙地、科尔沁沙地、浑善达克沙地及毛乌素沙地的羊柴(Hedysarum laeve)为对象,采用野外测量、石蜡切片技术及叶片解离技术,观察、分析了羊柴叶片形态及组织结构的地域分异特征,并就其形态、结构与生态因子间进行了相关性研究。结果表明:(1)随着干旱程度的加剧,羊柴叶片在形态上表现为变小、变厚,侧生小叶变长、变宽;在结构上表现为单位面积气孔数量减少,上、下表皮细胞变厚,栅栏组织越发达,栅栏细胞排列紧密,主脉维管束直径变大,疏导能力加强。(2)羊柴叶肉中存在大量的异细胞,具有抵御干旱及贮藏等功能,是对干旱环境长期适应的体现。(3)生长季降水量、年均降水量及年均蒸发量是形成羊柴小叶形态、结构地域分异的主要环境因子。以上结果表明植物对地域分异的响应不仅体现在外部形态上,在组织结构上同样产生相应的分异特征,而水热条件则是产生分异的主要因素。     

Complementation and Expression Analysis of SoRab1A and SoRab2A in Sugarcane Demonstrates Their Functional Diversification

Mammalian and plant Rabl and Rab2 are small GTPases that regulate vesicle trafficking in the endoplasmic reticulum （ER） to Golgi compartments. Little is known about their functional diversification or potential interaction. We cloned sugarcane （Saccharum officinarum L.） Rab1A and Rab2A genes and studied their functional differences by expression and complementation experiments. We found differential expression of the two genes during sugarcane leaf development： SoRab2A expression declined from the dividing base to the maturing tip of the growing leaves, whereas SoRab1A was constitutively expressed, suggesting that SoRab2A is required for cell division and expansion and SoRablA is required for cells at all developmental stages. We used a yeast temperature sensitive ypt1-A 136D mutant strain to further investigate these shared and unique functions. Yptl is a small GTPase that regulates vesicle transport in the same cellular location as Rabl and Rab2. Neither SoRab1A nor SoRab2A alone could restore the growth of the mutant at restrictive temperatures when SoRab1A and SoRab2A were transformed separately. However, SoRab1A transformants maintained normal morphology and viability at non-permissive temperature, and resumed growth when returned to permissive temperature, whereas SoRab2A transformants died at non-permissive temperature, suggesting that SoRablA function is required for a cell＇s viability. Mutant growth was fully restored when SoRab1A and SoRab2A were co-transformed, indicating that SoRablA and SoRab2A complement each other and they both are needed to restore the function of ypt1-A136D. These results demonstrate that SoRab1A and SoRab2A serve distinct but overlapping functions, mostly by regulating the transportation of different sets of proteins.     

On morphological variation in Keratella cochlearis populations from Holstein lakes (Northern Germany)

Keratella cochlearis occurs in many Holstein lakes (northern Germany) as three well defined and separated forms: cochlearis, hispida, and tecta, each showing very little variation between the lakes. The present data show that the tecta form did not originate from a Lauterborn cycle.     

三种根瘤菌诱变菌株的形态特征及其与抗性的关系

用紫外线照射四季豆根瘤菌(R.Phaseoli)、豌豆根瘤菌(R.Leguminosarm)和花生根瘤菌(R.Peanut),然后观察其形态特征,并将不同形态特征菌落的菌株接种于不同pH值YEM培养基和不同NaCl浓度的YEM培养基上培养。结果表明,突变株的抗酸碱性和抗盐性随根瘤菌不同而异,并与其菌落形态有关。     

辽宁地区药用植物根际土壤真菌多样性的研究

作者于2007和2008年的5-10月间在辽宁省的丹东、凤城、清原、桓仁等药材产区采集土壤样品200余份,通过采用稀释平板法和土壤颗粒平板法进行土壤真菌的分离和培养,共分离和鉴定出27属54种真菌,其中接合菌2属3种、子囊菌1属1种、无性型真菌24属50种。分离到的部分真菌种类是重要的药用植物病原菌,如Cylindrocarpon destructans、Fusarium oxysporum和F.solani。研究发现,Penicillium paxilli、P.expansum、Trichoderma atroviride及T.viride的分离频率最高,是辽宁省4个调查地区药用植物根际土壤真菌的优势菌群。     

The role of plasticity in resource capture by plants

Comparative experiments measuring the form and extent of plant responses to environmental factors allow an ecologically important distinction to be made between morphological plasticity and cellular acclimation. The two phenomena are associated with different sets of plant traits with which they occur with highest fidelity and potency at opposite ends of productivity gradients. A trade-off between scale and precision occurs with respect to the responses of plants to patchiness in resource supply and this provides valuable predictors of the status achieved by species in plant communities.     

模拟氮沉降对夏蜡梅幼苗生长及非结构性碳水化合物的影响

以一年生夏蜡梅（Sinocalycanthus chinensis）幼苗为研究对象,设置4种氮水平：对照（CK,0 gN·m^-2·a^-1）、低氮（N1,2 gN·m^-2·a^-1）、中氮（N2,8 gN·m^-2·a^-1）、高氮（N3,32 gN·m^-2·a^-1）,处理1年后,测定不同氮沉降水平下夏蜡梅幼苗生长指标、生物量分配以及非结构性碳水化合物的差异,探讨夏蜡梅幼苗对氮沉降的响应机制。结果表明：随着氮浓度的增大,夏蜡梅幼苗的株高、基径呈现先升高后降低的趋势,它们均以中氮处理最高。随着氮浓度的升高,夏蜡梅幼苗的叶、冠层生物量呈现出逐渐升高的趋势,而茎、根、总生物量、根生物量比和根冠比则表现出先升高后降低的趋势。叶生物量比随着氮浓度的升高呈现先降低后升高的趋势。叶平均周长、叶平均长度、叶平均面积均以中氮处理最大;叶宽长比以高氮处理最高;中氮、高氮处理的比叶面积明显低于对照。叶中的淀粉、非结构性碳水化合物（NSC）含量均以中氮处理最高;茎中的淀粉、NSC含量以高氮处理最低。总之,不同浓度氮沉降均促进了夏蜡梅的生长,中氮处理促进作用最明显,对其他生长和生理指标也产生了一定的影响。     

怒江干热河谷杧果种质资源形态性状遗传多样性分析

通过对255份怒江干热河谷杧果种质资源的24个形态性状进行评价,分析其遗传多样性。结果表明,怒江干热河谷杧果种质资源的果实单果重量、果实长度、果核重量、果核长度、果实形状、果皮颜色、果肉颜色、果实香气、果实风味、果实成熟期等形态性状均具有丰富的多样性。11个数量性状的变异系数为12.44%~56.44%,其中果实单果重量的变异系数最大,叶片宽度最小;13个质量性状的Shannon-weaver指数范围为0.68~2.21,平均值为1.42,其中果肉颜色指数最大,叶片质地指数最小。聚类结果将255份杧果材料聚为3大类,其中果皮厚,果小,种核大,可食率低,早熟,品味酸甜,品质差的杧果种质占很大比例。这些种质资源在不同地区收集的材料之间存在明显的遗传差异,但部分地区内的杧果材料表现出明显的遗传分化。通过表型评价鉴定,初步筛选出具有独特香气、反季节开花结果、早熟、小果型、高产等性状的特异种质资源35份。