泡沙参复合体（桔梗科）的物种生物学研究：Ⅰ表型的可塑性

表型可塑性是生物变异中由环境引起的一种变异,是植物适应的一种重要方式。对沙参属这样一个形态上复杂多变、分类上很难处理的类群,研究其表型可塑性不仅为探讨性状变异、判断其系统学意义及选择可靠的分类性状提供了有益的资料,而且有助于揭示沙参属植物变异、适应和进化的机制。本文从泡沙参复合体中选择了6个居群,利用播种和移栽试验,通过对不同个体和居群在一致条件下的表现及野外和移栽后的对比,对根、茎、叶、花和果等形态性状的表型可塑性进行了初步的观测分析。结果表明,一些叶片、花部和果实性状具有较大的发育可塑性,尤其是叶形、花萼裂片不仅发育变化大,而且随发育过程定向变化。环境可塑性较大的性状主要是根、茎、花序分枝等性状,而叶片、花部、果实和种子性状的环境饰变能力都较小。最后,对泡沙参复合体形态性状的变异从发育可塑性和环境可塑性的角度进行了讨论。     

Biosystematic Studies on Adenophora potaninii Korsh. Complex (Campanulaceae). Ⅰ. Phenotypic Plasticity

Phenotypic plasticity is the environmental modification of genotypic expression and an important means by which individual plants respond to environmental heterogeneity. The study of phenotypic plasticity in the genus Adenophora, which is very complicated taxo nomically because of great morphological variation, proves to be helpful in both investigating the phenotypic variation so as to evaluate potential taxonomic value of their characters and providing important sources of information on the variation, adaptation and evolution of the genus. Twenty-three populations representing all the six species in Adenophora potaninii complex were transplanted into the garden. Of them six populations were selected for study ing their performance in the field and in the garden, in addition to cultivation experiment under different treatments. The results show that there exists considerable developmental plasticity in some leaf, floral and capsule characters. In particular, the leaf shape and length of calyx lobe display significant developmental variation with the maximum being three times as great as the minimum, which is noteworthy because they were previously considered as diagnostic. The characters of root, caudex, stem and inflorescence are found to be very plastic, especially the root diameter, the number of stems, stem height and inflorescence length with great environmental plasticity. In addition, the populations from different habi tats show distinct amounts of plasticity. On the contrary, the characters of leaf, floral, cap sule and seed are less influenced by environments. It seems that the considerable variation in the characters of leaf is attributed mainly to genetic differences. Finally, the phenotypic plasticity of morphological characters of A. potaninii complex and its taxonomic significanceis discussed.     

Determination of morphological variation in subspecies of Isatis glauca Aucher ex Boiss. from Central Anatolia

Isatis glauca Aucher ex Boiss. has four subspecies: glauca, galatica Y?ld?r?ml?, sivasica (Davis) Y?ld?r?ml? and iconia (Boiss.) Davis, naturally growing in Turkey. In this study, 77 accessions from nine I. glauca ssp. populations were characterised in terms of variation in morphological characters, including the number of branches per plant, plant height, diameter of stem base, diameter of middle stem, diameter of apical stem, width and length of fruit, length of fruit stalk, fruit shape, fruit base shape, fruit apices shape, loculus, ondulation, apical process of fruit, fruit weight, basal length of fruit, apical length of fruit, wing width of fruit, loculus length, loculus width, length of seed, dorsal width of seed, lateral width of seed and seed weight. The number of branches had the highest value of coefficient of variation (CV), 0.21–0.86, while the fruit width had the lowest value of CV 0.08–0.20. According to Pearson’s correlation and multiple regression analyses, eco-geographical factors had a substantial effect on morphological variation. A principal component analysis explained 90.61 % of morphological variation through the study of five extracted components. A dendrogram, which was constructed according to the between-group linkages method, based on squared Euclidean distances, represented a hierarchical cluster analysis of 77 accessions. The results of the principal coordinate analysis, which showed differentiation according to morphological characters between nine populations, were consistent with the dendrogram. Consequently, morphological variation of I. glauca ssp. and the significant effects of eco-geographical factors on its morphological variation were discussed.     

TEMPORAL VARIATION OF FLOWER AND FRUIT SIZE IN RELATION TO SEED YIELD IN CELANDINE POPPY (CHELIDONIUM MAJUS; PAPAVERACEAE)

Ecological and evolutionary studies typically consider variation in single reproductive characters in isolation, without considering how they might be correlated with other reproductive and vegetative characters. In our study, we examined temporal patterns of variation and correlation in flower diameter and fruit length during a reproductive phase in two Massachusetts populations of the herb, Chelidonium majus. We also examined the relationships of such variation to measurements of seed yield components (mean seed weight and number per fruit) and aspects of plant vegetative size. Most of the variation in the sizes of reproductive characters occurred within individual plants, instead of among plants or between populations. Flower and fruit sizes as well as seed number per fruit declined significantly during the season in both populations. Only mean seed size per fruit was relatively stable for individual plants in both populations. Conserving resources by a gradual reduction in the size of reproductive characters over the season may be a strategy for maternal plants to continue seed production. The strong, persistent patterns of correlation between certain characters, such as flower and fruit size, in spite of extensive phenotypic plasticity, was interpreted as indirect evidence for developmental correlation. Furthermore, vegetatively larger plants produced not only more flowers and fruits, but also consistently larger flowers and fruits. The results emphasize that variation in fitness characters, such as seed size and number, should not be viewed in isolation from vegetative characters, flower, and fruit sizes in ecological and evolutionary studies, if the goal is to understand the mechanisms of natural selection in wild populations.     

Inflorescence architecture affects pollinator behaviour and mating success in Spiranthes sinensis (Orchidaceae)

? Despite the wide inflorescence diversity among angiosperms, the effects of inflorescence architecture (three-dimensional flower arrangement) on pollinator behaviour and mating success have not been sufficiently studied in natural plant populations. ? Here, we investigated how inflorescence architecture affected inter- and intra-plant pollinator movements and consequent mating success in a field population of Spiranthes sinensis var. amoena (S. sinensis). In this species, the flowers are helically arranged around the stem, and the degree of twisting varies greatly among individuals. The large variation in inflorescence architecture in S. sinensis results from variation in a single structural parameter, the helical angle (the angular distance between neighbour-flower directions). ? The numbers of visits per inflorescence and successive probes per visit by leaf-cutting bees decreased with helical angle, indicating that individual flowers of tightly twisted inflorescences received less visitations. As expected from pollinator behaviour, pollinia removal and fruit set of individual flowers decreased with helical angle. Meanwhile, geitonogamy decreased in tightly twisted inflorescences. ? Our novel findings demonstrate that natural variation in inflorescence architecture significantly affects pollinator behaviour and reproductive success, suggesting that inflorescence architecture can evolve under pollinator-mediated natural selection in plant populations. We also discuss how diverse inflorescence architectures may have been maintained in S. sinensis populations.     

Plasticity of inflorescence traits in Lobelia siphilitica (Lobeliaceae) in response to soil water availability

Many workers have demonstrated a genetic basis for variation in inflorescence traits, but this variation can also have an environmental component. Because flowering can incur significant water costs, I estimated plasticity of inflorescence traits of three populations of Lobelia siphilitica in response to drought. I manipulated soil water availability in the greenhouse and measured seven inflorescence traits. Under drought conditions, plants from one population flowered later and produced fewer flowers with shorter corollas and narrower landing pads. In contrast, the height of the flowering stalk decreased in response to drought in all three populations. Consequently, pollinator-mediated natural selection on these plastic traits may depend on soil water availability. Plastic responses differed between genotypes only for the height of the flowering stalk and the length of the corolla tube and only in one or two populations. This suggests that genotype × environment interactions would not limit the evolution of inflorescence traits in L. siphilitica. The strength and sign of phenotypic correlations among inflorescence traits did not respond plastically to drought, suggesting that indirect selection on inflorescence traits of L. siphilitica will not vary strongly with water availability. My results suggest that plasticity of inflorescence traits may influence their evolution, but the effects are population- and trait-specific.     

Genetic analysis of traits distinguishing outcrossing and self-pollinating forms of currant tomato,Lycopersicon pimpinellifolium (Jusl.) Mill

The evolution of inbreeding is common throughout the angiosperms, although little is known about the developmental and genetic processes involved. Lycopersicon pimpinellifolium (currant tomato) is a self-compatible species with variation in outcrossing rate correlated with floral morphology. Mature flowers from inbreeding and outcrossing populations differ greatly in characters affecting mating behavior (petal, anther, and style lengths); other flower parts (sepals, ovaries) show minimal differences. Analysis of genetic behavior, including quantitative trait locus (QTL) mapping, was performed on representative selfing and outcrossing plants derived from two contrasting natural populations. Six morphological traits were analyzed: flowers per inflorescence; petal, anther, and style lengths; and lengths of the fertile and sterile portions of anthers. All traits were smaller in the selfing parent and had continuous patterns of segregation in the F(2). Phenotypic correlations among traits were all positive, but varied in strength. Quantitative trait locus mapping was done using 48 RFLP markers. Five QTL total were found involving four of the six traits: total anther length, anther sterile length, style length, and flowers per inflorescence. Each of these four traits had a QTL of major (>25%) effect on phenotypic variance.     

Spatio-temporal variation in pollen limitation and reproductive success of two scape morphs in Primula farinosa

In plant populations where reproductive output is limited by pollinator visitation, plants with attractive floral displays should have a selective advantage. We examined the effect of inflorescence height on pollination success in Primula farinosa, which is dimorphic for scape length. To test the hypothesis that fruit and seed initiation are more strongly pollen-limited in the short-scaped than in the long-scaped morph, and that this difference is affected by spatio-temporal variation in pollen limitation, we conducted a hand-pollination experiment in four populations over 2 yr. Pollen limitation of fruit initiation varied among populations and years, and was stronger in the short-scaped than in the long-scaped morph. The results suggest that interactions with pollinators will need to be considered for a full understanding of the maintenance of this striking polymorphism. The study also shows that, although pollen limitation is likely to vary in space and time in many plant species, such variation is not necessarily associated with variation in selection on floral characters.     

QTL analysis of morphological traits in eggplant and implications for conservation of gene function during evolution of solanaceous species

An interspecific F(2) population from a cross between cultivated eggplant, Solanum melongena, and its wild relative, S. linnaeanum, was analyzed for quantitative trait loci (QTL) affecting leaf, flower, fruit and plant traits. A total of 58 plants were genotyped for 207 restriction fragment length polymorphism (RFLP) markers and phenotyped for 18 characters. One to eight loci were detected for each trait with a total of 63 QTL identified. Overall, 46% of the QTL had allelic effects that were the reverse of those predicted from the parental phenotypes. Wild alleles that were agronomically superior to the cultivated alleles were identified for 42% of the QTL identified for flowering time, flower and fruit number, fruit set, calyx size and fruit glossiness. Comparison of the map positions of eggplant loci with those for similar traits in tomato, potato and pepper revealed that 12 of the QTL have putative orthologs in at least one of these other species and that putative orthology was most often observed between eggplant and tomato. Traits showing potential orthology were: leaf length, shape and lobing; days to flowering; number of flowers per inflorescence; plant height and apex, leaf and stem hairiness. The functionally conserved loci included a major leaf lobing QTL ( llob6.1) that is putatively orthologous to the potato leaf ( c) and/or Petroselinum ( Pts) mutants of tomato, two flowering time QTL ( dtf1.1, dtf2.1) that also have putative counterparts in tomato and four QTL for trichomes that have potential orthologs in tomato and potato. These results support the mounting evidence of conservation of gene function during the evolution of eggplant and its relatives from their last common ancestor and indicate that this conservation was not limited to domestication traits.     

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.     

黄河下游湿地芦苇形态变异研究

 以水盐为主导生态因子,分析了黄河下游湿地芦苇(Phragmites australis)种群形态变异的水平与格局。对基径、株高、叶长、叶宽、节间长、节间数和穗长7个形态特征在15个种群中的变异分析表明：种群内个体间形态差异极显著,7个形态特征在种群内的变异系数从大到小依次为节间长（0.284 6）、叶宽（0.253 6）、穗长（0.244 9）、叶长（0.208 5）、基径（0.187 5）、节间数（0.176 3）、株高（0.165 7）; 7个形态特征在种群间的变异度从大到小依次为株高、叶长、节间长、叶宽、基径、节间数、穗长,但种群间形态的显著差异主要存在于滨州种群（BZH）、淡水种群（ZHG、DPH、NYH,土壤总盐度<0.1%）、盐生种群（HS01、HS02、HS03、HS04、HS05、DWL、KD、GD、LZH、LJ、DLH,土壤总盐度>0.3%）之间,在来自相似生境的种群间形态差异普遍不显著;7个形态特征均与水盐联合影响因子显著相关;以形态特征为基础的聚类分析将研究的15个种群分为显著不同的３类。因此,根据黄河下游湿地芦苇形态变异规律和分化特点,建议将该地区芦苇分为盐生芦苇、淡水芦苇、巨型芦苇3个形态类型。     

Gen-ecology of capsella bursa-pastoris from an altitudinal transsect in the Alps

Summary Seeds were collected in wild populations of Capsella bursa-pastoris growing along a cline from low elevations to the high mountain region in Switzerland. Progeny were grown in open field random block experiments and a number of relevant characters was measured. Germination behaviour showed no relationsship to the place of origin and exhibits considerable phenotypic plasticity. Flowering, plant height, rosette diameter and leaf forms displayed genotypic variations that were correlated with altitude. Along the considered altitude gradient phenotypic plasticity was overruled by genetic variation. Later flowering genotypes replaced the earlier flowering genotypes along the topocline which indicates retarded maturity and prolongation of the life cycle at high altitude.     

内蒙古扁蓿豆种质资源花性状的变异分析

采用形态学标记的方法,对来源于内蒙古7个不同生态区的49份扁蓿豆（Medicago ruthenica L.）野生材料进行了花性状变异分析。对花萼长、花萼直径等12个性状进行系统调查和遗传多样性分析。结果表明：扁蓿豆材料间花性状的变异系数幅度最大的为花序长,其变异系数高达79.12%,变异幅度最小的为花萼直径, 其变异系数为3.82%;主成分分析表明,花性状中前7个主成分反应了总信息量的85.465％, 花序长、花序轴长、花冠长度、花序结荚数、花序种子数、花色和小花柄长等7个性状是造成扁蓿豆花性状变异的主要因素;相关分析表明,花性状间多数呈差异显著或极显著,例如:花序结荚数与花序种子数差异极显著,为0.811,呈显著正相关,而花序轴长和小花柄长差异极显著,呈显著负相关,为-0.340;聚类分析将49份材料分为6类, 花性状变异性相同或地理来源相同与相近的材料大部分聚在一起。说明：扁蓿豆材料间的花性状具有丰富的遗传多样性     

Phenotypic plasticity in alpine Erigeron species (Asteraceae)

Utelli, A.-B., Huber, W. & Zopfi, H.-J. 1995. Phenotypic plasticity in alpine Erigeron species (Asteraceae). — Nord. J. Bot. 15: 483–492. Copenhagen. ISSN 0107–055X.
Twelve morphological characters were analysed in 67 E. alpinus, E. neglectus and E. uniflorus plants which had been transplanted from their natural habitat to the greenhouse. Mean values and standard deviations were compared for each species. The phenotypic plasticity of the characters resp. their genetic basis was estimated from the correlation of morphological data recorded on single individuals, each grown under both ecological conditions.
A considerable phenotypic plasticity was found in all species and for most characters. E. unijlorus was the most constant species regarding taxonomically relevant characters such as pubescence of the basal leaves, number of flowering heads and number of filiform flowers. In all three species the same highly significant directional variation in plant height and involucre length was found which suggests that these characters have some genetic basis in Erigeron .     

紫距淫羊藿的地理分布新记录及形态描述

淫羊藿属依据少量栽培个体命名的类群普遍存在,往往缺乏足够的野外调查和形态性状统计,对其性状变异幅度、变异式样和分类价值研究不够。紫距淫羊藿(Epimedium epsteinii)由Stearn于1997年依据引种个体命名,为掌握其资源分布及形态性状变异,该研究基于居群概念,对淫羊藿属分布区展开调查,在各分布区选择一个居群(30个体/居群)于花期进行形态观察、统计和描述。结果表明:紫距淫羊藿以往被认为狭域分布于湖南天平山,该研究调查发现广东省和湖北省均有分布,为新分布记录。此两处新分布分别位于天平山的南部和北部,将其自然分布区显著扩大。基于居群观测的形态变异较原描述更广泛。6个主要数量性状(株高、序轴长、小花数、叶长、叶宽和根茎)和花部颜色在居群间和个体间均呈现丰富的变异。生物种的分布范围并非完全连续,而是由若干个多少间断的居群组成,任何一个居群都存在不同程度的连续性变异,要更好地认识各物种,就应当足够重视这些居群系统。紫距淫羊藿的新分布记录对淫羊藿属的资源利用、扩散机制和系统地理学研究具有重要意义。     

POLLINATION IN FLORAL SCENT MORPHS OF POLEMONIUM VISCOSUM: A MECHANISM FOR DISRUPTIVE SELECTION ON FLOWER SIZE

Plants of Polemonium viscosum have flowers that are either sweet or skunky in scent. The two morphs are preferentially pollinated by insects of strongly contrasting body size: bumblebee queens specialize on sweet flowers, flies on skunky ones. In this study 13 characters were examined in plant specimens from five populations to identify major components of intraspecific variation in flower and inflorescence morphology and test their correlation with floral scent. Factor analysis identified four major axes of morphological variation. The first explained 22% of the variance among specimens and correlated strongly with four flower size characters: sepal length, corolla tube length, corolla lobe width, and corolla lobe length. Floral scent morphs differed significantly in the multivariate representation of flower size defined by these characters. Sweet flowers had wider corolla lobes, longer corolla tubes, and longer sepals than skunky ones. Corolla lobe width accounted for the greatest amount of intermorph divergence. Divergence in flower size between morphs was maintained in mixed populations at four locations in alpine Colorado, with corollas of sweet flowers significantly broader or more flared than those of skunky flowers. Patterns of pollen receipt suggest that this difference is adaptive. In the sweet morph, pollination intensity and purity increased significantly with corolla flare. Conversely, in the skunky morph, corolla flare had little influence on pollination intensity and had a strong negative effect on purity. These findings suggest that selection for effective pollination should favor intraspecific divergence in flower size in Polemonium viscosum.     

Gender modification in a monoecious species <Emphasis Type="Italic">Sagittaria potamogetifolia</Emphasis> (Alismataceae)

In order to find out if the inflorescences number variation has influences on the gender modification in plant species, we investigated the gender modification in a cultivated population of the monoecious species Sagittaria potamogetifolia. We also designed two nutrient levels to explore the impact of nutrient on gender modification in S. potamogetifolia. We found that the female and male flowers did not change with increasing plant size for each inflorescence at a low nutrient level. At a high nutrient level, the female flower numbers on each inflorescence did not increase with plant size; however, the male flower numbers had some positive correlation with the plant size. At the ramet level, the total male and female flower numbers increased with the plant size at both nutrient levels. The sex ratio (female to male flower ratio) decreased with the inflorescence numbers and the plant size (Midvein length). Although the nutrient variation had impact on the flower number production, it did not change the gender modification pattern. The high plasticity of inflorescence numbers, which caused the gender variation in S. potamogetifolia, and low plasticity of female and male flowers on a single inflorescence, indicates that the limited modification on gender in a single inflorescence may be compensated by inflorescence number variation at the ramet level.     

Principal Component Analysis on Morphological Variation in the Saussurea nipponica Complex (Compositae)

Abstract For the understanding of morphological differentiation and recognition of natural groups in the Saussurea nipponica complex, 440 individuals from 19 populations were examined, especially by using statistical methods. The variation range of 16 morphological characters within and between populations were analyzed not only separately but also synthetically by Duncan's multiple range test, principal component analysis, and cluster analysis. Of the 16 characters examined, characters concerning plant size (height and diameter of stem, size of involucre, etc.) and involucral bract (length of involucral bract and recurved part of involucral bract) are suggested to be important to recognize natural groups. Five groups are recognized by a complex pattern of the morphological characters. They can be defined multivariately as natural groups having indegenous habitat and distribution range, and considered as subspecies of S. nipponica.     

Morphological variation in Puya (Bromeliaceae): an allometric study

A group of representative species of the genus Puya was studied to determine if there are allometric relationships between vegetative and floral parts, whether these relationships correlate with their pollination system and if plant size is correlated with elevation and latitude. Fifty-three species representing the morphological variation and distribution of the genus were studied. Total plant height, as well as leaf, inflorescence, petal and sepal length were measured and these data subjected to univariate and multivariate analyses. To test for correlation between plant size and altitudinal and latitudinal distribution, ANOVAs were performed. When the pollination system of a species is known, additional multivariate and univariate analyses were also performed. The results indicate that the characters studied are correlated with a size component, exhibiting positive allometry for sepal and petal length and negative allometry for leaf length. Inflorescence length is an isometric character. There was no significant correlation between plant size and altitudinal or latitudinal distribution. The ANOVAs show that the only character correlated to pollinator type was petal length. Small plants with small flowers are correlated to pollinators such as insects, while medium to large plants with medium to large-sized flowers are correlated with pollinators such as birds and bats. Large plants have small flowers, that are more evident and attract more pollinators.