Floral sex ratio variation in hermaphrodites of gynodioeciousChionographis japonica var.kurohimensis Ajima et Satomi (Liliaceae)

Intrapopulation and interpopulation variations in floral sex ratio in hermaphrodites of gynodioeciousChionographis japonica var.kurohimensis (Liliaceae) were examined. The relative ratio of male flowers to total flowers (male and perfect flowers) decreased with plant size, suggesting size-dependent gender modification. The relative ratio of male flowers per population-basis is negatively correlated with the mean number of perfect flowers. Since the number of perfect flowers proportionally increased with plant size, populations showing low maleness consist of relatively bigger plants and are considered to be in high-quality environment. On the other hand, the relative ratio of male flowers per population basis is independent of female frequency in the population. Plasticity in gender expression probably plays an important role of maintenance of gynodioecy inC. japonica var.kurohimensis.     

Germination ofRubus palmatus var.coptophyllus andR. microphyllus seeds buried in soil for 7.5 years

Seeds of twoRubus species,R. palmatus var.coptophyllus andR. microphyllus, buried for 7.5 years in soil were subjected to germination tests to investigate their germinability and germination traits. Most of the retrieved seeds were viable, and germinated at the alternating temperatures of 20/30°C in both light and dark. The twoRubus species showed similar responses of germination to temperature and light, although the final percentages of germination were slightly higher inR. palmatus var.coptophyllus. These characteristics of seed dormancy and germination would be involved in the species' utilization of ephemeral habitats created by unpredictable and infrequent disturbances.     

光枝勾儿茶内生真菌多样性及抑菌活性研究

为探索贵州苗药光枝勾儿茶内生真菌类群特征、分布部位及其抑菌活性,该研究采用传统方法对贵州省贵阳市和黔西市光枝勾儿茶内生真菌进行分离,并基于分子生物学及统计学对其分类地位进行鉴定及多样性评价,最后通过微量肉汤倍比稀释法筛选具有抑菌活性的菌株。结果表明:(1)从光枝勾儿茶中分离到191 株内生真菌,隶属于3 个门5 个纲10 个目15 个科19 个属,优势属为叶点霉属(Phyllosticta)、间座壳属(Diaporthe)、葡萄座腔菌属(Botryosphaeria)和刺盘孢属(Colletotrichum)。(2)黔西光枝勾儿茶内生真菌香农-维纳多样性指数(H''_Q=2.112)较贵阳(H''_G=1.801)高,索伦森相似性指数Cs_G-Q为0.923,不同组织香农-维纳多样性指数为茎(H''_S=2.004)>根(H''_R=1.764)>叶(H''_L=1.654)>果实(H''_F=1.473),茎和叶内生真菌的索伦森相似性最高(Cs_S-L=0.667)。(3)筛选出的21株内生真菌对供试菌大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)和沙门氏菌(Salmonella enterica)具有抑菌效果,其中Diaporthe sp. QX4G6对大肠杆菌、金黄色葡萄球菌和沙门氏菌的最小抑菌浓度分别为12.5、6.25、12.5 mg·mL^-1,最小杀菌浓度分别为12.5、6.25、12.5 mg·mL^-1。以上研究结果揭示了光枝勾儿茶蕴藏丰富的内生真菌资源,不同地区及组织内生真菌类群组成有差异,多个分离菌株具有抗菌活性,为光枝勾儿茶内生真菌天然抗菌药物或药源研发奠定了基础。     

糜子黄、黑种皮遗传及转录组学分析

同源异型域-亮氨酸拉链(homedomain-leucine zipper,HD-Zip)转录因子广泛参与植物的生长发育和抗胁迫过程。该研究通过生物信息学方法对青稞HD-Zip基因家族进行全基因组分析鉴定,并采用qRT-PCR技术分析非生物胁迫下该基因的表达特性,为深入探讨青稞HD-Zip转录因子的生物学功能及其在高原作物抗逆育种中的应用奠定基础。结果表明：(1)成功从青稞基因组中共鉴定出41个HD-Zip基因家族成员,依次命名为i>HvvHD-ZipⅠ-1~Ⅳ-13,且这些基因在7条染色体上呈不均匀分布。(2)理化性质分析发现,HvvHD-Zip蛋白包含197～885个不等的氨基酸残基;分子量范围在19 914.36～94 014.87 Da;亚细胞定位表明HvvHD-Zip蛋白都位于细胞核。(3)根据多序列比对、系统进化、基因结构和保守基序差异将其聚为4个亚家族,各亚家族分类特征与系统聚类结果一致。(4)顺式作用元件预测分析发现,i>HvvHD-Zip基因启动子中含有11种植物激素和胁迫响应元件。(5)qRT-PCR结果显示,HvvHD-Zip Ⅰ、Ⅱ、Ⅳ亚家族基因对各胁迫响应明显;与根组织相比,多数i>HvvHD-Zip基因在叶组织中响应明显(上调或下调);与冷和盐胁迫相比,i>HvvHD-Zip各基因对旱胁迫响应较强。     

钾对兰州百合鳞茎中多酚类物质积累代谢及其抗氧化活性的影响

为探究施钾对兰州百合鳞茎中多酚类物质的积累、抗氧化能力及差异代谢物的影响,该研究以兰州百合鳞茎为试材,通过固定氮素(N)和磷素(P)用量,设置不同钾(K)浓度处理,即K_(0)(不施肥)、K_(1)(447.6 mg·L^(-1))、K_(2)(671.4 mg·L^(-1))、K_(3)(895.2 mg·L^(-1)),采用福林-肖卡法、溴甲酚绿比色法、香草醛比色法、DPPH法、铜离子还原能力(CUPRAC)法测定不同K浓度处理下兰州百合鳞茎中多酚类物质含量及其抗氧化活性,并采用LC-MS法分析多酚类物质的差异代谢物,并进行差异代谢物筛选,功能注释及富集分析,为兰州百合的优质栽培提供理论依据。结果表明:(1)不同K浓度处理下兰州百合鳞茎中多酚类物质的含量及其抗氧化活性存在显著差异(P<0.05),与K_(0)相比,K_(1)、K_(2)、K_(3)均能促进鳞茎多酚类物质的积累及其抗氧化能力的提高,其中以K_(2)(671.4 mg·L^(-1))效果最佳。(2)相关性分析表明,兰州百合鳞茎多酚类物质含量与抗氧化活性指标呈极显著(P<0.01)相关关系,相关系数为0.451~0.959。(3)K_(0)、K_(2)浓度处理下兰州百合鳞茎中存在89种多酚类及相关化合物,其中52种相对含量显著上调,37种相对含量显著下调,且显著富集到黄酮类及苯丙类化合物生物合成的通路上。研究认为,兰州百合的最佳施钾量(671.4 mg·L^(-1))能有效促进鳞茎中多酚类物质的积累并提高其抗氧化能力。     

鸢尾柄锈菌一新变种及柄锈属国内一新记录

本文报道采自东北地区的鸢尾柄锈菌一新变种和柄锈属一国内新记录种。新变种命名为鸢尾柄锈菌多孔变种[Puccinia iridis(DC.)Wallr.var.polyporis W.C.Liu var.nov.],区别于原变种的主要特征是其夏孢子小,芽孔5—7个,散生;而后者夏孢子较大,芽孔2—4个,赤道生。新记录种是短果茴芹柄锈菌(Puccinia pimpinellae-brachycarpae Tranzsch.et Ere-meeva),寄生在短果茴芹(Pimpinella brachycarpa Nakai)上。标本保存于沈阳农业大学真菌标本室和中国科学院微生物研究所真菌标本室。     

Casearia Essential Oil: An Updated Review on the Chemistry and Pharmacological Activities

Casearia species are found in the America, Africa, Asia, and Australia and present pharmacological activities, besides their traditional uses. Here, we reviewed the chemical composition, content, pharmacological activities, and toxicity of the essential oils (EOs) from Casearia species. The EO physical parameters and leaf botanical characteristics were also described. The bioactivities of the EOs from the leaves and their components include cytotoxicity, anti-inflammatory, antiulcer, antimicrobial, antidiabetic, antioxidant, antifungal, and antiviral activities. The main components associated with these activities are the α-zingiberene, (E)-caryophyllene, germacrene D, bicyclogermacrene, spathulenol, α-humulene, β-acoradiene, and δ-cadinene. Data on the toxicity of these EOs are scarce in the literature. Casearia sylvestris Sw. is the most studied species, presenting more significant pharmacological potential. The chemical variability of EOs components was also investigated for this species. Caseria EOs have relevant pharmacological potential and must be further investigated and exploited.     

MONOCLONAL ANTIBODIES AS MOLECULAR MARKERS FOR THE INTRACELLULAR AND CELL WALL DISTRIBUTION OF CARRAGEENAN EPITOPES IN KAPPAPHYCUS (RHODOPHYTA) DURING TISSUE DEVELOPMENT1

Carrageenan, the major cell wall carbohydrate of certain red algae, is variable in structure and gelling properties. Sequence types include gelling (kappa and iota) and nongelling (lambda) types in addition to precursors, often in hybrid molecules containing more than one precursor and/or sequence type. Molecular markers to subunits were needed to study carrageenan synthesis, cell wall organization, and the relationship between structure and function. Monoclonal antibodies were produced to carrageenan, and their specificities were determined by competitive enzyme immunoassay. Antibodies were identified with specificities related to kappa, iota, and lambda carrageenan. The patterns of immunofluorescence localization on Kappaphycus alvarezii = Eucheuma alvarezii var. tambalang (Doty) sections were distinctive for each antibody. The antibody to a kappa-related epitope labeled mature tissue strongly; antibodies to an iota-related epitope and a lambda-related epitope labeled weakly, consistent with the kappa-enriched carrageenan produced by this alga. Kappa-related epitopes were distributed throughout the wall and matrix, whereas iota-related epitopes were concentrated in the middle lamella. Lambda-related epitopes were localized primarily at the plant cuticle where kappa and iota antigens were lacking. An antibody appeared to be specific for a precursor of the gelling subunits because it showed maximal wall and intracellular labeling at the youngest developmental stage. All antibodies labeled intracellular inclusions in the transition zone between the epidermis and medulla during the development of medullary cells from the peripheral meristem in young branches. The results demonstrate the intracellular synthesis of epitopes related to all major carrageenan subunits and their differential extracellular distribution.     

Soil-surface carbon dioxide efflux and microbial biomass in relation to tree density 13 years after a stand replacing fire in a lodgepole pine ecosystem

The effects of fire on soil‐surface carbon dioxide (CO₂) efflux, F_S, and microbial biomass carbon, C_mic, were studied in a wildland setting by examining 13‐year‐old postfire stands of lodgepole pine differing in tree density (< 500 to > 500 000 trees ha^?1) in Yellowstone National Park (YNP). In addition, young stands were compared to mature lodgepole pine stands (～110‐year‐old) in order to estimate ecosystem recovery 13 years after a stand replacing fire. Growing season F_S increased with tree density in young stands (1.0 µmol CO₂ m^?2 s^?1 in low‐density stands, 1.8 µmol CO₂ m^?2 s^?1 in moderate‐density stands and 2.1 µmol CO₂ m^?2 s^?1 in high‐density stands) and with stand age (2.7 µmol CO₂ m^?2 s^?1 in mature stands). Microbial biomass carbon in young stands did not differ with tree density and ranged from 0.2 to 0.5 mg C g^?1 dry soil over the growing season; C_mic was significantly greater in mature stands (0.5–0.8 mg C g^?1 dry soil). Soil‐surface CO₂ efflux in young stands was correlated with biotic variables (above‐ground, below‐ground and microbial biomass), but not with abiotic variables (litter and mineral soil C and N content, bulk density and soil texture). Microbial biomass carbon was correlated with below‐ground plant biomass and not with soil carbon and nitrogen, indicating that plant activity controls not only root respiration, but C_mic pools and overall F_S rates as well. These findings support recent studies that have demonstrated the prevailing importance of plants in controlling rates of F_S and suggest that decomposition of older, recalcitrant soil C pools in this ecosystem is relatively unimportant 13 years after a stand replacing fire. Our results also indicate that realistic predictions and modeling of terrestrial C cycling must account for the variability in tree density and stand age that exists across the landscape as a result of natural disturbances.     

High-elevation rock outcrop vegetation of the Southern Appalachian Mountains

Abstract. Species composition patterns and vegetation-environment relationships were quantified for high-elevation rock outcrops of the Southern Appalachian Mountains, an infrequent and insular habitat in a forested landscape. Outcrops occur over a wide geographic range encompassing extensive variation in both geology and climate. Geographic-scale factors interact with site-scale factors to produce variation in vegetation among outcrops. Similarly, site-scale factors interact with micro-scale factors to produce variation in vegetation within outcrops. To provide a quantitatively-based classification of outcrop vegetation we used a TWINSPAN analysis of 154 100-m² plots. We recognized nine communities that primarily correspond to different combinations of elevation, bedrock type, geography, and moisture. Within outcrops of a single bedrock type, vegetation composition of 100-m² plots was consistently correlated with elevation and solar radiation, but relationships to soil nutrients varied with bedrock type. Both site-scale (100 m²) factors (e.g. elevation, slope, aspect, and bedrock type) and plot-scale (1-m²) microsite factors (e.g. soil depth, vegetation height, soil nutrients) were strongly correlated with species composition at the 1-m² level. Environment can be used to predict composition more effectively for 100-m² plots on a single bedrock type than either across bedrock types or at a 1-m² scale. Composition-environment relationships resemble those described for outcrop systems from other regions with pronounced topographic relief more than they do those described for the nearby but flatter and lower-elevation outcrops of the Southeastern Piedmont. There is strong spatial autocorrelation in this community, perhaps owing to dispersal limitation. Consequently, a comprehensive conservation strategy must include reservation of both a range of geologic types and a range of geographic locations.