小黑瓢虫形态特征及生物学特性观察

小黑瓢虫(Delphastus catalirtae(Horn))是粉虱害虫的重要捕食性天敌。本对小黑瓢虫从英国引种后的形态特征和生物学特性进行观察,用福州地区新的猎物寄主高氏瘤粉虱(Aleurotubercutatus takahashii David＆Subramaniam)进行饲养繁殖,已成功地在室内定殖和繁衍。小黑瓢虫成虫寿命长达90—130天．可捕食粉虱卵、若虫、成虫各虫态,且捕食量大,活动能力强,是高氏瘤粉虱的有效天敌,具有很好的保护利用价值。     

黑木耳8808菌株生物学特性研究

黑木耳8808菌株,是笔者几年来,从黑龙江省15个地区,采集的32个样本中,分离的59个野生菌株中,经多次培养、比较,栽培试验选出的一株优质、高产菌株。该菌株1992年,在本省五常县长山乡生产150万袋,全省生产近1000万段,均获丰收,产量、质量均明显优于原生产菌株。为更好的为生产提供科学依据,本文研究了该木耳孢子弹射及萌发特征,菌丝、子实体、孢子形态,不同温度、pH、氮碳源浓度,不同培养料配方对该木耳菌丝生长及产实影响。     

Pollen tube growth and the pollen‐tube pathway of Nymphaea odorata (Nymphaeaceae)

An important aspect of the evolution of carpel closure, or angiospermy, is the relationship between pollen tube growth patterns and internalization of the pollen‐tube pathway. True carpel closure, involving postgenital fusion of inner carpel margins, is inferred to have arisen once within the ancient order Nymphaeales, in the common ancestor of Nymphaeaceae. We studied pollen tube development, from pollination to fertilization, in a natural population of Nymphaea odorata, using hand pollinations and timed flower collections. Pollen germinates in stigmatic secretions within 15 min and pollen tubes enter subdermal transmitting tissue within an hour, following wide intercellular spaces towards the zone of postgenital fusion. At the zone of fusion they turn downwards to grow in narrow spaces between interlocked cells and then wander freely to ovules within ovarian secretions. The pollen‐tube pathway is 2–6 mm long and upper ovules are first penetrated 2.5 h after pollination. Pollen tubes grow at rates of approximately 1 mm/h whether in stigmatic fluid, transmitting tissues or ovarian secretions. Pollen‐tube pathways are structurally diverse across Nymphaeales, yet their pollen tubes have similar morphologies and rapid growth rates. This pattern suggests pollen tube growth innovations preceded and were essential for the evolution of complete carpel closure. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 162 , 581–593.     

Phylogeny and species delineation in the marine diatom Pseudo‐nitzschia (Bacillariophyta) using cox1, LSU,and ITS2 rRNA genes: A perspective in character evolution

Analyses of the mitochondrial cox1, the nuclear‐encoded large subunit (LSU), and the internal transcribed spacer 2 (ITS2) RNA coding region of Pseudo‐nitzschia revealed that the P. pseudodelicatissima complex can be phylogenetically grouped into three distinct clades (Groups I–III), while the P. delicatissima complex forms another distinct clade (Group IV) in both the LSU and ITS2 phylogenetic trees. It was elucidated that comprehensive taxon sampling (sampling of sequences), selection of appropriate target genes and outgroup, and alignment strategies influenced the phylogenetic accuracy. Based on the genetic divergence, ITS2 resulted in the most resolved trees, followed by cox1 and LSU. The morphological characters available for Pseudo‐nitzschia, although limited in number, were overall in agreement with the phylogenies when mapped onto the ITS2 tree. Information on the presence/absence of a central nodule, number of rows of poroids in each stria, and of sectors dividing the poroids mapped onto the ITS2 tree revealed the evolution of the recently diverged species. The morphologically based species complexes showed evolutionary relevance in agreement with molecular phylogeny inferred from ITS2 sequence–structure data. The data set of the hypervariable region of ITS2 improved the phylogenetic inference compared to the cox1 and LSU data sets. The taxonomic status of P. cuspidata and P. pseudodelicatissima requires further elucidation.     

Origins of female genital diversity: Predation risk and lock‐and‐key explain rapid divergence during an adaptive radiation

The study of male genital diversity has long overshadowed evolutionary inquiry of female genitalia, despite its nontrivial diversity. Here, we identify four nonmutually exclusive mechanisms that could lead to genital divergence in females, and potentially generate patterns of correlated male–female genital evolution: (1) ecological variation alters the context of sexual selection (“ecology hypothesis”), (2) sexually antagonistic selection (“sexual‐conflict hypothesis”), (3) female preferences for male genitalia mediated by female genital traits (“female‐choice hypothesis”), and (4) selection against inter‐population mating (“lock‐and‐key hypothesis”). We performed an empirical investigation of all four hypotheses using the model system of Bahamas mosquitofish inhabiting blue holes that vary in predation risk. We found unequivocal support for the ecology hypothesis, with females exhibiting a smaller genital opening in blue holes containing piscivorous fish. This is consistent with stronger postmating female choice/conflict when predators are present, but greater premating female choice in their absence. Our results additionally supported the lock‐and‐key hypothesis, uncovering a pattern of reproductive character displacement for genital shape. We found no support for the sexual conflict or female choice hypotheses. Our results demonstrate a strong role for ecology in generating female genital diversity, and suggest that lock‐and‐key may provide a viable cause of female genital diversification.     

The distribution and systematic relevance of the androecial character oligomery

Localization of the stamens can be approached by a preliminary distinction between two characters, oligomery and polymery, occurring in two different groups of taxa, respectively the oligomerous complex and the polymerous complex. Oligomery is described by four character states standing in a close semophyletic relationship: diplostemony, obdiplostemony, haplostemony and obhaplostemony. Each character state is analysed for its distribution and systematic value. Diplostemony is the synapomorphic character state for the oligomerous line and has arisen once from a polymerous ancestor or in parallel in different lines. Obdiplostemony arises ontogenetically in three different ways. Loss of one whorl leads either to obhaplostemony, or haplostemony; both character states are believed to represent evolutionary steps of no-return. Secondary increases and reductions of the stamens within a whorl are seen as expressions of the intrinsic variability of the character states and should not be homologized with them. Stamen numbers can be increased by the building-up of complex primordia or by secondary receptacular growth. Reductions of stamens affect one or two whorls of stamens and are caused by lack of space, interactions with the gynoecium and zygomorphy. The distribution of the different character states of oligomery is presented on Dahlgrenograms and the androecia of a number of families and their relationships are discussed. The interactions between oligomery and polymery are analysed as guidelines for a global phylogeny of the Magnoliatae.     

麻楝种子形态和营养特征遗传变异分析

为系统揭示麻楝种源间种子形态和营养成分的变异程度和变异规律,以8个国家26个种源麻楝种子为试验材料,对不同种源麻楝种子的形态特征和营养成分进行比较分析。多重比较结果表明,麻楝种源间种子的长、宽、厚、长宽比、百粒重以及可溶性蛋白质、可溶性糖和淀粉含量差异极显著;相关分析表明,种子百粒重与种子长、种子宽呈极显著正相关,可溶性蛋白质、可溶性糖和淀粉含量与百粒重均呈极显著正相关;主成分分析结果显示,影响麻楝种子品质的第1主成分主要是种子形态性状,即种子长、百粒重和种子宽,第2主成分是种子营养成分;通过分析麻楝种子形态特征及营养成分变异系数可知,麻楝种子形态变异系数大于营养成分变异系数,表明种子形态受外界环境影响较大。通过主成分聚类分析,将26个种源分为2个集群,第1集群包括澳大利亚和马来西亚2个种源,其特点是种子形态较大、百粒较重、养分含量较高;第2集群包括其余24个种源。结合聚类分析和种子形态与地理气候因子相关分析结果可知,麻楝种子形态变异具有一定的地理区域特征,与分布区的自然地理因素有一定的相关性,麻楝分布区南部种子较大而北部种子较小。     

Phylogeny,biogeography, and morphological ancestral character reconstruction in the Mediterranean genus Fumana (Cistaceae)

Fumana is a diverse genus of the Cistaceae family, consisting of 21 currently accepted species. In this study, nuclear (ITS) and plastid (matK, trnT‐L) molecular markers were used to reconstruct the phylogeny and to estimate divergence times, including 19 species of Fumana. Phylogenetic analyses (Bayesian Inference, Maximum Parsimony and Maximum Likelihood) confirmed the monophyly of Fumana and did not support the infrageneric divisions previously established. The results support four main clades that group species that differ in vegetative and reproductive characters. Given the impossibility to define morphological characters common to all species within the clades, our proposal is to reject infrageneric divisions. Molecular dating and ancestral area analyses provide evidence for a Miocene diversification of the genus in the north‐western Mediterranean. Ancestral state reconstructions revealed ancestral character states for some traits related to xeric and arid habitats, suggesting a preadaptation to the Mediterranean climate.     

青天葵野生变家栽的探讨——Ⅰ.生物学特性的观察

青天葵是广西特产药材,过去一直处于野生状态,药源日渐枯竭.供不应求。作者通过调查和研究,掌握了它的生态条件和生物学特性。实践证明,青天葵由野生变为人工栽培是可能的。