中国云实属植物叶脉形态学

对中国云实属植物小叶叶片脉序的观察表明,该属植物小叶叶片脉序类型非常一致,均为环结曲行羽状脉,二级脉急转曲行.叶脉分支一般为四级,少数达五级.盲脉不分支或分支较少,最多两次分支.见血飞亚属与云实亚属叶片脉序特征相似,属于同一自然类群.编写了中国云实属植物叶片脉序特征分种检索表.     

中国木犀属植物叶脉形态及其分类学意义

观察了中国木犀属植物4组19种叶脉形态。主要分析木犀属植物叶片脉序走向,脉序为环结曲行或半直行羽状脉。二级脉急转曲行或半直行,叶脉分支一般为4级,少数5级。盲脉1～2次分支,少数3次或不分支。仅柊树叶缘末级脉汇合成边脉.部分叶缘具齿,叶缘齿性状不稳定,因其内主脉不同而在本属种间表现出一个连续的变异过程。圆锥花序组与李榄属和木犀榄属从叶片脉序特征方面表现出较近的亲缘关系。四个组的叶脉形态在演化上关系上与花粉形态表现相一致。编写了叶片脉序特征分种检索表。     

石韦属植物脉序特征及其分类学意义

采用解剖学方法,研究了水龙骨科鹿角蕨亚科石韦属(Pyrrosia)17种植物的脉序特征,并与该科其它3亚科8属8个代表种的脉序进行了对比。结果显示,石韦属植物的脉序属于结合脉序,并可进一步细分为弯脉蕨型和拟槲蕨型。根据脉序特征的聚类分析表明,石韦属植物的结合脉序与水龙骨科其它属植物的结合脉序具有显著差异,且此脉序特征是石韦属内较稳定的分类性状,具有一定的分类学价值。本研究还基于脉序特征,讨论了石蕨(P.angustissimum(Giesenh.ex Diels)TagawaK.lwats.)、抱树石韦(P.piloselloides M.G.Price Kalikasan)与其它石韦属植物的亲缘与进化关系。     

中国裸齿角石蛾属三新种(毛翅目,齿角石蛾科)

描述了裸齿角石蛾属3新种,即脊状裸齿角石蛾Psilotreta vertebrata sp.nov.(广东)、方背裸齿角石蛾Psilotreta cuboides sp.nov.(云南)和凹入裸齿角石蛾Psilotreta excavata sp.nov.(江西)。模式标本保存于南京农业大学昆虫标本馆。     

Cotyledon venation patterns in the Leguminosae: Gaesalpinioideae

Cotyledon venation patterns are described for 93 species representing all tribes of the Caesalpinioideae. Patterns are grouped into a series of levels of complexity according to the number of primary veins, nine, seven, six, five, three or one, but five- and three-vein patterns predominate. The number of petiolar vascular strands varies from one to eight but most species have two or four strands. It is proposed that all the patterns have been derived from one in which four strands and a protoxylem trace in the petiole branch and anastomose to form seven primary veins in the lamina. Venation patterns show correlations with cotyledon anatomy, size and shape and with taxonomic grouping at tribal, infratribal and generic levels. Each tribe is characterized by a particular set of related patterns, pattern frequencies and evolutionary trends.     

现存蜉蝣翅基纵脉走向及愈合模式(昆虫纲：蜉蝣目)

有翅昆虫翅基纵脉的走向及愈合模式在系统发育重建中占有重要地位。然而,现存蜉蝣翅基纵脉的走向及愈合状况在大部分种类变化极大,无法推测其原始状况,只在极少数种类保留有部分可见残迹。中国拟短丝蜉Siphluriscus chinensis的翅基保留有独立的亚前缘脉弓、部分中脉M和肘脉Cu主干以及前中脉MA及径分脉Rs的走向痕迹。据此并结合红斑蜉Ephemera rufomaculata 和大网脉蜉Chromarcys magnifica翅基的相关特征,本文提出了蜉蝣目主要纵脉基部走向及愈合的基本模式,其要点有：中脉主干在基部与径脉主干独自发出后先接近或愈合后又分离、它们各自分成两支后的前中脉及径分脉又先愈合再分离、肘脉始终独立。这种中脉与径脉先接近或愈合后分离的模式非常接近新翅类的情况而与蜻蜓很不相同(在蜻蜓,中脉与肘脉在基部愈合) 。亚前缘脉弓的作用相信是加强了因翅基骨板发达而相互远离的纵脉间的连结作用。这个假说也可以来解释蜻蜓复杂脉相的形成原因。     

WEREWOLF, a MYB-related protein in Arabidopsis, is a position-dependent regulator of epidermal cell patterning

The formation of the root epidermis of Arabidopsis provides a simple and elegant model for the analysis of cell patterning. A novel gene, WEREWOLF (WER), is described here that is required for position-dependent patterning of the epidermal cell types. The WER gene encodes a MYB-type protein and is preferentially expressed within cells destined to adopt the non-hair fate. Furthermore, WER is shown to regulate the position-dependent expression of the GLABRA2 homeobox gene, to interact with a bHLH protein, and to act in opposition to the CAPRICE MYB. These results suggest a simple model to explain the specification of the two root epidermal cell types, and they provide insight into the molecular mechanisms used to control cell patterning.     

被子植物花对称性的遗传控制

简要评述了被子植物花对称性遗传控制研究的最新进展。金鱼草中控制花背腹轴不对称性基因Cy cloidea(Cyc)和Dichotama(Dich)的克隆 ,为研究单对称花的遗传控制机理和进化历程提供了可能。在唇形目(Lamialess .l.)中的研究表明 ,在与金鱼草 (Antirrhinummajus)近缘的物种中 ,Cyc基因的同源基因可以采用相似的机制控制背腹轴上花器官的不对称性发育。最新的研究结果显示 ,在同金鱼草远缘的豆科植物 (Legu minosae)中 ,不仅存在Cyc基因的同源基因 ,而且它们也参与花背腹轴上不对称性的形成。参与花对称性控制的基因属于植物中一个新发现的基因家族———TCP结构域基因     

An efficient method for estimating vein density of Glossopteris and its application

Glossopteris-type leaves are the most abundant floristic element from the Gondwanan continent and are recorded throughout the Permian, which was a period of extreme icehouse-to-hothouse climatic global change. Fossil leaf traits can be useful for the reconstruction of palaeoenvironments and identification of climatic changes throughout geological time, but the conservative morphology of Glossopteris leaves has thus far made them difficult to use for this purpose. If the characters of Glossopteris can be better quantified then it should make them useful for tracking environmental changes over a wide geographical area and over a long time interval. Venation density is a highly variable leaf trait that might be useful for this purpose. This trait can be calculated, usually as vein length per centimetre squared, but this can be a time-consuming procedure. In this paper we propose a new rapid method to estimate venation density in a conical sector of Glossopteris leaf lamina using an accurate linear model whose predictors are three linear venation densities, measured as veins per centimetre. In addition to substantially reducing the data collection time, it is less biased and more reproducible than methods applied previously with this leaf type. Using this more robust method, preliminary results significantly distinguish the venation densities of leaves produced in wet and drier ecosystems, matching a pattern similar to modern plants. This is the first survey using a large sample size to reveal that environmental stress controlled the vein architecture of Palaeozoic plants, in a manner similar to plants in modern ecosystems.