Species delimitation in the Luziola peruviana (Poaceae) complex

Luziola is a small genus from aquatic environments of the New World. The most widespread species in the genus isL. peruviana. Morphological variation has been documented for this species throughout its entire range of distribution, however this variation has been difficult to characterize. A population aggregation analysis was performed in order to determine how many species can be identified when analyzing characters from the individuals of this taxon as well as with individuals from closely related taxa such asL. divergens, L. doelliana, andL. pittieri. Multivariate analysis, ANOVA and ANCOVA analyses were also performed to detect if quantitative morphological variation is related to altitude and latitude. Results indicate that within this complex only one species should be recognized, referable toL. peruviana, and that plants near the equator are larger, and have larger lemmas and paleas in both female and male flowers. An identification key for the nine species now recognized inLuziola is included.     

Timing and success of reproductive stages in the seagrass Zostera noltii

The timing and success of sexual reproduction of the seagrass Zostera noltii was investigated at the Ria Formosa lagoon, Portugal. Thirty plants were tagged and monitored individually through time to determine in situ the development time of each maturation stage, from the emergence of the flowers to the production of seeds. The overall process of flowering and fruiting lasted 47 ± 4 days, during which formation and maturation of the fruits was the most time-consuming stage (27 ± 2 days). Spathe success, i.e. the percentage of spathes that produced seeds, was 22 ± 4% while spathe mortality was 34 ± 6%. A considerable percentage of spathes (37 ± 7%) was lost through leaf detachment, but some of these may still add to the reproductive success of the species by contributing to the species recruitment within the source meadow or elsewhere. Meadow seed production (MSP) of Z. noltii was estimated to be 312 ± 66 seeds m⁻², whereas the potential seed production of the studied meadow was 2623 seeds m⁻². Under laboratory conditions, 70% of Z. noltii seeds germinated within 26 days, but only 10% reached the seedling stage due to the high mortality of germlings. Fertility, defined as the probability of a seed to originate a new plant, was estimated to be 14 × 10⁻⁴, which is higher than what is expected for most seagrasses.     

华北地区繁缕属（Stellaria L.）植物叶表皮微形态特征研究

采用光学显微镜,对华北地区分布的繁缕属植物16种2变种,其它4属4种植物的叶表皮微形态进行了观察。结果表明：繁缕属植物叶片的下表皮均存在气孔器,而上表皮仅少数种类缺乏气孔器。气孔器类型比较多样,有不等细胞型、无规则型、无规则四细胞型;表皮细胞主要为不规则型,垂周壁从平直、弓形、浅波状、波状、到深波状;上表皮气孔指数在5.23~31.65之间;下表皮气孔指数在10.02~29.44。叶表皮被毛或无,毛被分为星状毛、腺柔毛、柔毛、绢毛。该研究说明叶表皮的微形态特征在种间差异明显,可以为分种及属间亲缘关系的探讨提供依据,但是对组的划分存在一定的局限性。     

武汉市15种阔叶乔木滞尘能力与叶表微形态特征

以武汉市15种常见的阔叶乔木为研究对象,通过3级滤膜过滤法测定了各乔木单位叶面积滞留不同粒径颗粒物(TSP、PM_(10)、PM_(10)、PM_(2.5))的质量,并通过扫描电镜观察比较了15种乔木的叶表面微形态结构,分析了微形态对植物滞尘能力的影响。结果表明:15种乔木单位叶面积的滞尘量存在显著差异(P0.05),综合滞尘能力最强的植物为二球悬铃木、桂花和石楠,除以上3者外,女贞和广玉兰分别具有较强的滞留PM_(10)和PM_(2.5)的能力;加杨滞留TSP和PM_(10)的能力最弱,玉兰滞留PM_(10)和PM_(2.5)的能力最弱。各乔木单位叶面积滞留PM_(2.5)和PM_(10)的质量分别占总粉尘量的0.7%—8.9%和3.6%—33.9%。叶表面微结构观察表明,叶表面粗糙、褶皱较多,或被有蜡质层的植物有利于粉尘颗粒物的附着。相关性分析表明,植物单位叶面积的滞尘量与叶表面沟槽的宽度呈显著相关,上下表面沟槽宽度越小,越有利于细微颗粒物(PM_(2.5))的滞留,下表面沟槽宽度增加,有利于粉尘总颗粒物(TSP)的滞留。由此可见,叶表面粗糙度、蜡质含量和沟槽宽度等微形态结构是调控绿化树种叶片滞尘能力的重要因素,在武汉以治理大气粉尘污染为目标进行城市绿化时,可考虑选择二球悬铃木、桂花和石楠等滞尘能力强的树种。     

Anchusa formosa (Boraginaceae), a new species from Southern Sardinia (Italy)

ABSTRACT

A new Anchusa species was discovered in the massif of Mt. Lattias in South-Western Sardinia. This species, here described as A. formosa, shows a sharp phenotypic differentiation from the other Sardinian endemic taxa of Anchusa, especially in habit, leaf shape and size, inflorescence and calyx morphology. Ecological traits are also peculiar, the plant being restricted to siliceous debris that accumulates in small depositional areas of dry stream beds. A. formosa is likely to represent a paleogenic schizoendemism originated through isolation and genetic drift from the same genie pool of the other Corso-Sardinian endemic taxa of Anchusa. SEM analyses provide additional information on the micromorphology of the stigma and its papillar pattern, pollen grains, mericarp coat surface and trichomes. The anatomical structure of stem, root and leaf were also analysed. Due to its extreme localization and ecological specialization, A. formosa needs total protection in its natural habitat and should be added to National and International Red Lists of plants at risk of extinction.     

见血封喉种子中的强心苷类化合物及其细胞毒活性

从海南产见血封喉(Antiaris toxicaria (Pers.) Lesch.)种子的乙醇提取物中分离得到7个强心苷类化合物,通过波谱分析(NMR, MS, IR等),鉴定其结构分别为：杠柳苷元(1)、见血封喉阿洛糖苷(2)、见血封喉去氧阿洛糖苷(3)、毒毛旋花子苷元(4)、毒毛旋花子阿洛糖苷(5)、毒毛旋花子爪哇糖苷(6)和去葡萄糖桂竹香毒苷(7)。化合物7为首次从见血封喉种子中分离得到。细胞毒活性测试结果表明,化合物1~7均对慢性髓原白血病细胞(K562)、人胃癌细胞(SGC-7901)和人肝癌细胞(SMMC-7721)的增殖有较强的生长抑制活性。     

Trichome micromorphology of the East Asiatic genus Chelonopsis (Lamiaceae) and its systematic implications

The micromorphology of trichomes of the leaves of 17 taxa (including two varieties) of the genus Chelonopsis Miq. and of six species representing four additional genera (Bostrychanthera deflexa Benth., Colquhounia coccinea Wall. var. coccinea, Co. seguinii Vaniot. var. seguinii, Gomphostemma chinense Oliv. var. chinense, G. crinitum Wall. ex Benth. and Physostegia virginiana (L.) Benth.) was surveyed by light and scanning electron microscopy. Two basic types of trichomes can be identified: non-glandular and glandular trichomes. The non-glandular trichomes can be subdivided into two subtypes: simple unbranched and branched trichomes. Based on the cell number, simple unbranched trichomes are further divided into four shapes (unicellular, two-celled, three-celled, and more than three cells), whilst branched trichomes are separated into three shapes (biramous, stellate, and dendroid trichomes). The glandular trichomes can in turn be subdivided into four subtypes: subsessile, capitate, clavate, and sunken. Non-glandular trichomes with two cells (NGTW) and subsessile glandular trichomes (GSU) are most widespread in all taxa examined. The indumentum shows considerable variation among different sections or species. Consequently, trichome micromorphology and distribution have high taxonomic value for Chelonopsis at both infrageneric and interspecific levels. The presence of capitate glandular trichomes (GCA) provides an additional morphological character to clarify the boundaries between subgenus Chelonopsis and Aequidens Wu and Li. Within subgenus Aequidens, non-glandular trichomes with more than three cells (NGMT) and clavate glandular trichomes (GCL) are important characters for sectional division between sect. Aequidens Wu and Li and sect. Microphyllum Wu and Li. Again, three forms of three-celled trichomes can be used as a distinctive taxonomic character at specific level between C. albiflora Pax et K. Hoffm. ex Limpr., C. forrestii J. Anthony, and C. souliei (Bonati) Merr. in sect. Aequidens. This study supports Wu's delimitation of subgenus and sections and the subsequent review work by Xiang et al. Additionally, distribution of trichome types is correlated with the altitudinal distribution and habitats of some species in Chelonopsis.     

烟台甜樱桃柱头的可授性、形态特征与坐果率

采用数码照相、电镜扫描、联苯胺-过氧化氢测试及去雄套袋等技术手段, 对烟台甜樱桃(Cerasus avium)花期不同发育阶段柱头的可授性、形态特征和坐果状况进行了观察。结果表明, 烟台甜樱桃在套袋状态下, 柱头可授期从开花前1天开始可持续5–7天。从杯状花期到花瓣平展期, 柱头逐渐有乳突细胞破裂并呈现分泌液, 出现渐强的可授性; 从花瓣平展期到花瓣脱落期, 柱头由暗黄渐变至暗黑, 逐渐萎缩并丧失可授性。去雄套袋及人工授粉实验结果显示, 在大蕾期、杯状花期、花瓣展放期、花瓣平展期和花瓣脱落期进行人工授粉, 烟台甜樱桃的坐果率分别为60.50%、58.33%、62.08%、57.14%和39.13%。在自然条件下烟台甜樱桃的坐果率一般为30%–42%, 传粉成功的最佳期主要发生在杯状花期至花瓣平展期。     

肿足蕨属植物叶表皮微形态及其系统学意义

利用光学显微镜对9种肿足蕨属植物即肿足蕨、光轴肿足蕨、修株肿足蕨、鳞毛肿足蕨、稻城肿足蕨、球腺肿足蕨、山东肿足蕨、福氏肿足蕨、腺毛肿足蕨和2种近缘种林下凸轴蕨及大膜盖蕨叶表皮微形态进行观察。结果表明:9种肿足蕨属植物的叶表皮细胞均为不规则型,垂周壁为深波状;叶上下表皮均有毛;气孔器类型有6种,为极细胞型、腋下细胞型、不等细胞型、不规则四细胞型、不规则细胞型和横列型。不同种间叶表皮微形态特征表现出一定差异,对种的划分有一定的分类学意义。讨论了肿足蕨属植物与蹄盖蕨科、鳞毛蕨科、金星蕨科、林下凸轴蕨及大膜盖蕨的亲缘关系,为肿足蕨属植物的系统学研究提供新的资料。