Morphological variation and female reproductive success in two sympatric Trillium species: evidence for phenotypic selection in Trillium erectum and Trillium grandiflorum (Liliaceae)

I investigated the mating systems and phenotypic variation of two sympatric spring ephemerals, Trillium erectum and T. grandiflorum (Liliaceae), and phenotypic selection acting through female reproductive success for 11 morphological characters in five sympatric populations of the two species. I examined the degree of self-compatibility, pollinator-visitation rates, and pollen limitation of fruit and seed production in both species. Both Trillium species were self-compatible, but outcrossed flowers produced more successful fruits and seeds than self-pollinated flowers. Pollinator-visitation rates to the two species were low compared to other insect-pollinated spring ephemerals. In addition, both T. erectum and T. grandiflorum experienced pollen limitation in fruit and/or seed production; however, levels of fecundity in both species may be influenced by resource availability as well. I found significant phenotypic variation in 11 morphological characters within and among the five study populations. The sizes of all morphological characters were positively correlated. In general, larger T. erectum and T. grandiflorum produced more seeds. Phenotypic selection analysis revealed that direct and indirect selection acted on the size of morphological characters for both species. But there was no detectable selection acting on plant shape. This study reveals that variation in plant size exists within and among populations of both species, and this variation is associated with variance in female reproductive success. Spatial and temporal variation in pollinator and/or resource abundance may play a role in the phenotypic variation exhibited by both Trillium species.     

短命植物角茴香的开花物候与生殖特征

为了研究角茴香的开花物候特征及其对生殖成功的影响,于2015年对其自然种群各水平的开花物候指数、开花过程中的花部特征变化和结实特性进行了观察和统计。结果表明：（1）角茴香种群花期为4月下旬至5月下旬,种群水平的花期持续时间为36 d。（2）单花具有独特的花瓣结构,其内层花瓣由白色的侧裂片和黄色的兜状中裂片构成,中裂片是角茴香植物花粉二次呈现的关键功能器官;开花进程依其外层花瓣开裂大小可分为4个阶段,即外层花瓣顶端未张口、外层花瓣顶端张口5~7 mm、外层花瓣顶端张口12~14 mm和外层花瓣顶端张口3~5 mm。（3）花序水平的开花振幅曲线呈渐进式单峰曲线,开花同步指数为0.748,个体水平表现出较高的相对开花强度,其分布频度的偏斜率为0.45,主要频度范围分别集中在20%~30%和50%~70%之间。（4）花序水平的始花日期与花期持续时间存在显著负相关关系,开花数与座果数存在显著正相关关系。（5）自然状态下,角茴香结实率和结籽率分别是82.7%±0.1%和93.6%±0.8%。角茴香开花强度分布频度上出现的高、低强度的分异趋势是吸引传粉者、促进结实的有效生殖对策。     

山东新植物

本文报导了石竹属一新变种, 即山东石竹Diantus chinensis L.var.shandongensis J.X.Li et F.Q.zhou 及蓼属一新变型, 即直立篇蓄Polygonum aviculare L.forma erectum J.X.Li et Y.M.Zhang     

中国砖格孢子丝孢菌研究Ⅲ.囊梗孢属

本文报道囊梗孢属一新种和一中国新记录种.新种为直立囊梗孢Oncopodiumerectum G.Z.Zhao&T.Y.Zhang,其典型特征是分生孢子宽倒棒状或梨形,砖格状,几乎总是三个横膈膜.中国新记录种为李囊梗孢Oncopodiumpruni M.B.Ellis.对这两个种进行英文描述,并附图,新种具拉丁文描述.研究标本保存在山东农业大学植物病理学标本室(HSAUP).     

山西霍山罂粟科植物花粉形态

利用光学显微镜和扫描电子显微镜对山西霍山罂粟科白屈菜属白屈菜、紫堇属延胡索、角茴香属角茴香、秃疮花属秃疮花 4种的花粉形态进行了观察和比较研究 ,以上 4种花粉差异大。角茴香花粉粒近球形 ,具合沟 ;延胡索花粉粒长球形 ,表面纹饰较光滑 ;白屈菜花粉粒长球形或近球形 ;秃疮花花粉粒近球形。角茴香花粉表面纹饰为刺状纹和细网状纹的复合纹 ,白屈菜花粉表面纹饰为细网状纹和颗粒状纹的复合纹 ,秃疮花花粉表面纹饰为细颗粒状纹。延胡索、白屈菜、秃疮花花粉粒的萌发沟均为三沟 ,但沟的形态均不相同     

Genotypic diversity revealed by allozymes and oligonucleotide DNA fingerprinting in French populations of the aquatic macrophyte Sparganium erectum

The vast majority of perennial plants reproduce sexually and vegetatively at the same time. This may lead to important variation among clonal plant populations in their amount of genotypic diversity. In order to verify this assumption, we compare the clonal diversity of 10 natural populations of the aquatic clonal macrophyte Sparganium erectum in France. Diversity was quantified by DNA fingerprinting and allozyme electrophoresis for a sample of 10 shoots per population. Two DNA probes (CA)₈ and (TAA)₆ TA, were selected among 10 synthetic oligonucleotide probes containing simple repeat motifs. Both allozymes and DNA fingerprints revealed different amounts of diversity among populations. Five populations consist of a single genotype, whereas two populations were genetically highly diverse. In four of the monomorphic populations, absence of fingerprints diversity was combined with uniformly heterozygous allozyme loci, suggesting that each population was composed of a single clone. In the highly diverse populations, the level of clonal diversity combined with the allele segregation of the two allozyme loci Lap and Est suggests frequent seedling recruitment. The origin of new genotypes remains unclear but the absence of widespread genotypes together with the discrete distribution of Sparganium erectum populations implies that new genotypes are locally produced through sexual reproduction.     

沙生短命植物角茴香群落特征及生物学特性

采用抽样调查的方法对古尔班通古特沙漠南缘的8个角茴香自然群落的群落特征和生物生态学特性进行调查,对其群落特征和花部特征进行初步探究,为进一步对其传粉适应性以及繁育系统特征的研究奠定基础。结果表明:(1)角茴香群落中包含30种植物,隶属于15科28属,单种科、单种属较多。(2)根据群落组成和重要值可将8个角茴香自然群落划分为3个群丛,分别是角茴香+草地早熟禾+白茎绢蒿群丛、角茴香+艾比湖沙拐枣+白茎绢蒿群丛和角茴香+白茎绢蒿+蛇麻黄群丛。(3)角茴香种群、单株、花序和单花的花期分别历时37~40d、14~16d、13~15d和1~2d,单株结籽量700~900粒,种子千粒重(0.291 0±0.002 7)g,单花具有特殊的中裂片结构,具有雄蕊拟态和花粉二次呈现的功能。     

The Simulium vernum group (Diptera: Simuliidae) in Europe: multiple character sets for assessing species status

The value of using characters from multiple sources – chromosomes, ecology, gene sequences, and morphology – to evaluate the species status of closely related black flies is demonstrated for three European members of the Simulium vernum group: Simulium crenobium (Knoz, 1961), Simulium juxtacrenobium Bass & Brockhouse, 1990, and Simulium vernum s.s. Macquart, 1826. Simulium juxtacrenobium is a chromosomally, molecularly, and morphologically distinct species that diverged from S. crenobium and S. vernum s.s. about 2 Mya. It is specialized for intermittent streams, is univoltine, and is recorded for the first time from northern Europe, based on collections from Finland and Sweden, representing a range extension of about 1800 km. In contrast, S. crenobium, although confirmed as a distinct species, differs from S. vernum s.s. by only a few larval and chromosomal characters, and by a breeding habitat restricted to mountain spring brooks. Whereas all four character sets independently support the specific distinctness of S. juxtacrenobium and S. vernum s.s., multiple character sets are required to establish the specific validity of S. crenobium.     

中国砖格孢子丝孢菌研究III. 囊梗孢属

本文报道囊梗孢属一新种和一中国新记录种。新种为直立囊梗孢Oncopodium erectum G. Z. Zhao & T. Y. Zhang, 其典型特征是分生孢子宽倒棒状或梨形,砖格状, 几乎总是三个横膈膜。中国新记录种为李囊梗孢Oncopodium pruni M. B. Ellis。对这两个种进行英文描述,并附图,新种具拉丁文描述。研究标本保存在山东农业大学植物病理学标本室(HSAUP)。     

直立介蕨是假蹄盖蕨属的成员

对直立介蕨Dryoathyrium erectum (Z. R. Wang) W. M. Chu &; Z. R. Wang与介蕨属Dryoathyrium、假蹄盖蕨属Athyriopsis的叶、毛、孢子囊群和孢子的形态进行了比较研究。直立介蕨叶轴和羽轴上的沟槽不明显、具有单列细胞的节状毛、孢子囊群有双生一脉, 以及孢子的形态等特征与假蹄盖蕨属植物相似。结合叶绿体DNA trnL-F区序列分析结果, 所有形态及分子资料均表明该种植物应属于假蹄盖蕨属, 应恢复其原名直立假蹄盖蕨Athyriopsis erectum Z. R. Wang。