海南莎草科植物资源新探

通过野外资源调查,结合现阶段生物多样性发展需求对海南莎草科植物进行系统性、科学性的整理。结果发现,海南现有莎草科植物为24属、157种、9亚种和4变种。调查新增三肋果莎属（Tricostularia Nees）;新增新种长柄薹草（Carex longipetiolata）;新增11个新分布记录种,分别是细秆湖瓜草（Lipocarpha tenera）、类头状花序藨草（Trichophorum subcapitatum）、复序飘拂草（Fimbristylis bisumbellat）、宽叶多脉莎草（Cyperus diffusus var. Latifolius）、密穗莎草（C. eragrostis）、水蜈蚣（Kyllinga polyphylla）、三肋果莎（Tricostularia undulate）、截鳞薹草（Carex truncatigluma）、广东薹草（C. adrienii）、密苞叶薹草（C. phyllocephala）、中华薹草（C. chinensis）;调查统计发现12个海南特有种,分别是海南割鸡芒（Hypolytrum hainanense）、少穗割鸡芒（H. paucistrobiliferum）、节茎藨草（Scirpus chunianus）、澄迈飘拂草（Fimbristylis chingmaiensis）、多花剑叶莎（Machaerina myriantha）、海南高秆莎草（Cyperus exaltatus var. Hainanensis）、海南砖子苗（Mariscus hainanensis）、单子砖子苗（M. Monospermus）、线茎薹草（Carex tsoi）、扁茎薹草（C. planiscapa）、东方薹草（C. tungfangensis）、岩生薹草（C. Saxicola）。     

薹草属菱形果薹草组9种植物叶片的解剖学研究

利用石蜡切片法和叶表皮装片法对薹草属菱形果薹草组(Carexsect.Rhomboidales)9种植物进行叶片解剖结构特征观察。结果表明:9种植物的叶片解剖学特征总体上较一致,如横切面形状为"V"形或近"V"形,具气腔,中脉上方具泡状细胞,中脉维管束周围有不同程度的厚壁组织;上表皮细胞一般比下表皮细胞大;表皮下的叶肉细胞均出现不同程度的分化;叶表皮特征显示上、下表皮细胞均为长方形,垂周壁深波状弯曲,表现出近似种之间的相似性;表皮附属物为刺突状表皮毛;但不同种之间的叶解剖特征也有一定的区别,表现在泡状细胞层数、叶肉细胞分化层数和中脉维管束2端厚壁组织发达程度不同,气孔器在脉间成列或随机分布,气孔指数和气孔密度也有差异,可以作为区分种的依据。据此,本文提供了基于叶片解剖特征的9种植物分种检索表。     

班玛县气温和降雨量对禾本科、莎草科产草量的影响

选择典型的高寒草甸为研究对象,分析1995~2004年气温和降雨量变化对禾本科和莎草科产草量的影响。结果表明,禾本科产草量与气温呈线性函数关系变化,且相关性达到显著水平,禾本科产草量与降雨量的相关性不显著;莎草科产草量与气温的相关性不显著,莎草科产草量与降雨量呈线性函数关系变化,且相关性达到显著水平。     

小兴安岭莎草科植物资源调查

[目的]调查小兴安岭莎草科植物资源,为小兴安岭莎草科植物资源的保护和合理开发利用提供理论依据。[方法]采用野外调查和标本鉴定的方法,对该区莎草科植物属种的组成、分布区类型和区系特征进行研究。[结果]该区共有莎草科植物6属83种(含变种),且优势属明显,寡种属占总属数的50.00%。在属的分布类型上,以世界分布为主,且无中国特有属。[结论]小兴安岭莎草科植物组成丰富,区系地理成分多样。     

白马雪山莎草科胡萝卜状根植物的功能性状及环境响应

莎草科(Cyperaceae)植物在长期进化的过程中,在土壤环境较为恶劣的情况下,形成了特殊根系性状——胡萝卜状根(Dauciform roots)。为探究莎草科胡萝卜状根植物的功能性状及环境响应,本文以白马雪山上的两种莎草科植物为对象,通过野外调查并采集相关植株,测定其功能性状及体内元素含量,同时对所在区域的环境因子进行测定分析,进而明确该根系对环境的适应机制。结果表明,在自然生境下,生长有胡萝卜状根的莎草科植物的功能性状与体内元素含量密切相关,与叶形态特征和根性状之间存在正相关关系,植株表现出较高的生态适应性,在贫瘠的环境中有着较好的表现型。胡萝卜状根能够增加植物吸收磷的能力,进而提高植株的生产力,胡萝卜状根的形成可以部分解释莎草科植物在高寒草甸的独特表现。     

Vesicular-arbuscular mycorrhizae in tropical sedges of southern India

Twenty-four species of sedges (representing six genera) from different vegetation types in Western Ghats, South India, were examined for vesicular-arbuscular mycorrhizal (VAM) associations. All the sedges had VAM fungal infections with hyphae and vesicles, but arbuscules were observed only in 42% of the total species. The VAM fungal colonization varied considerably between species, ranging from 9 to 62%. Root colonization was positively and negatively correlated with root diameter and root hair length, respectively. The number of VAM fungal spores in the rhizosphere varied from 5 to 86 g^-1 soil. No significant relationship was found between spore numbers or root colonization and either soil pH or moisture. Four Glomus spp., one Acaulospora sp., one Sclerocystis spp., and one Gigaspora sp. were identified among the VAM fungal spores. The results reflect a high incidence of VAM in sedges occurring in Western Ghats and emphasize the need to assess the VAM status of plant species from different ecosystems to understand their mycorrhizal status.     

黑龙江产莎草科(Cyperaceae)一新记录种

在撰写《黑龙江植物志》(莎草科)过程中,发现莎草属(Cyperus)的白鳞莎草(Cyperus nipponicus Franch. et Sav.)为黑龙江省新记录种。其主要特征为:植株密集丛生。矮小,一般2—8 cm高。苞片叶状,明显长于花序。花序头状或球形,淡黄绿色,小穗扁平状,披针形或狭卵形,鳞片薄膜质。小坚果约为鳞片长的1/2。柱头2。本种喜生于湿地或江(湖)岸边沙地。     

油莎豆5-烯醇式丙酮酰莽草酸-3-磷酸合酶基因CeEPSPS的克隆与分析

起源于非洲和地中海沿岸的油莎豆以适应性广、产油量高而成为我国的新型油料作物。为促进该物种的开发与利用,研究基于基因组和转录组数据对油莎豆及代表性单子叶植物的EPSPS基因进行系统鉴定。结果表明：与大多数植物类似,油莎豆仅含有1个EPSPS基因,其包含7个内含子,命名为CeEPSPS;RT-PCR分离到的CeEPSPS编码区序列为1584 bp,预测编码514个氨基酸,其N端的前70个残基为叶绿体信号肽,77～508位残基为高度保守的EPSP合酶结构域（PF00275）;与EPSP合酶结构域相比,信号肽在不同植物中变异较大;CeEPSPS成熟蛋白的理论分子量为47.32 kDa,等电点为5.49,总平均疏水指数为0.069,脂肪族指数为93.76,不稳定系数为31.73,与其他物种相近,均属于稳定的疏水型酸性蛋白;进化分析支持油莎豆划归为禾本目莎草科。序列比对和基因组测序分析结果显示,56份油莎豆种质不存在已报道的草甘膦抗性变异。qRT-PCR分析结果显示,CeEPSPS主要在成熟叶片和块茎中表达,其表达水平显著高于芽、幼嫩叶片、衰老叶片和芽茎。此外,本研究还构建了CeEPSPS的植物过...     

Occurrence of stilbene oligomers in Cyperus rhizomes

Investigation of the chemical constituents of Rhizoma Cyperi (Cyperus rotundus Linneus) resulted in the isolation of novel enantiomeric and meso-stilbene trimers [i.e., (+)- and (−)-(E)-cyperusphenol A (1, 2 respectively) and (E)-mesocyperusphenol A (3)], a trimer bearing a novel hexacyclic ring system [cyperusphenol B (5)], as well as known stilbenoids (cyperusphenols C (4) and D (6), scirpusins A (7) and B (8), and piceid (9)) and luteolin. HPLC was used for the optical resolution of 1 and 2 as well as for the identification of cooccurrence of enantiomers of 7. The structures of the isolates were established by spectroscopic analyses, including a detailed NMR spectroscopic investigation. The isolates were evaluated in terms of their antiproliferative activity employing the Jurkat cell line (human T-cell leukemia cells), while the IC₅₀ potencies of a racemate of 1 and 2, 3, 5, and 6 were estimated as 27.4, 40.5, 26.4, and 26.3 μM, respectively. The suppression of cell growth by 6 was due to the induction of apoptosis, which was characterized by nuclear changes and PARP-1 cleavage determined by western blotting. We also evaluated the free radical scavenging activity of the isolates.