Inhibitory effects of different quantitative compositions of Hymenaea leaf resins on a generalist herbivore Spodoptera exigua

The hypotheses that quantitative variation in leaf resins in the leguminous genus Hymenaea may partially be a response to insect predation was tested in feeding experiments with the generalist herbivore, the beet armyworm, Spodoptera exigua Hübn (Noctuidae). Leaf resins of all Hymenaea species are comprised of essentially the same suite of sesquiterpene hydrocarbons, but discrete quantitative patterns have been classified as Compositional Types based on the amounts of major components. In this work pure extracts of leaf resins of Type I (high - and β-selinene), Type II (intermediate amounts of -and β-selinene and caryophyllene) and Type III (high caryophyllene) were incorporated into an artificial diet for the insects at 1 and 3.2% (dry wt). Resin Type treatments produced differential dose-dependent effects on growth rate (lower larval weights and increased time to pupation) and in mortality. More significant inhibitory effects occurred in Compositional Types with a predominance of a single compared (i.e. Types I and III). Significantly higher mortality occurring in Type III treatments suggests that caryophllene may have higher potential toxicity than - and β-selinene for S. exigua. These experiments indicate that feeding by generalist herbivores could be a factor determining quantitative compositional variation: (a) among populations; (b) during the development of leaves; (c) in the spatial distribution within the leaves; and (d) between parent tree and seedling progeny.     

Inhibitory effects of Hymenaea and Copaifera leaf resins on the leaf fungus, Pestalotia subcuticularis

Leaf resins in the leguminous genera Hymenaea and Copaifera may play a role in restricting infection by the associated leaf fungus, Pestalotia. We tested this hypothesis by assessing growth of the geographically widespread Pestalotia subcuticularis presented with different compositions of resins. Leaf resins of Hymenaea and Copaifera are composed of the same suite of sesquiterpene hydrocarbons, but these vary quantitatively to form discrete compositional patterns among individuals and populations. Leaf resins may also contain sesquiterpene oxides; caryophyllene oxide, which may have been formed from the caryophyllene precursor common in these resins, inhibited fungal growth in vitro.     

Population differentiation and phylogeography of Hygrophila pogonocalyx based on RAPDs fingerprints

Genetic variation of the endangered species, Hygrophila pogonocalyx Hayata (Acanthaceae), was estimated based on RAPD fingerprints. According to the criteria of the International Union for Conservation of Nature and Nature Resources, H. pogonocalyx is on the Red List Category due to its endangered status. Entomophilous plants of H. pogonocalyx are mostly pollinated by honeybees. Gene flow between populations is constrained by the migratory capacity of the pollinators. A survey based on RAPD fingerprinting using 50 random primers revealed the distribution of genetic variation following an “isolation by distance” model. A hierarchical AMOVA analyses indicated significant differentiation between geographical regions (Φ_ct=0.934; P=0.048), among populations (Φ_st=0.945; P<0.001), and among populations within region (Φ_sc=0.169; P<0.001). The differentiation between geographic populations may be ascribed to a long isolation since the formation of the Central Mountain Range 1 million years ago. In contrast to low levels of genetic variation in many endangered species, some genetic processes avoiding selfing may have evolved in H. pogonocalyx. Somatic mutation also possibly contributed to the variability maintenance within populations with limited size.     

Phenotypic variations in natural populations of Amygdalus pedunculata

Aims Our objectives were to determine the phenotypic variations, adaption and distribution patterns in seven natural Amygdalus pedunculata populations.Methods We analyzed 14 phenotypic traits from 120 individuals in seven populations of A. pedunculata by variance analysis, correlation analysis, and cluster analysis.Important findings Results showed that there were plentiful phenotypic variation within and among populations. In particular, the phenotypic variation within population was 40.91%, higher than that among populations (35.29%), which indicated that the phenotypic variation within population was the main source of the phenotypic variation in A. pedunculata. Mean differentiation coefficient was 45.90%, and mean coefficient of variation of 14 traits was 15.59%, ranged from 9.39% to 31.98%. Mean annual temperature, latitude, length of frost-free period, longitude and altitude appear to be prominent ecological factors influencing phenotypic traits. Mean annual temperature and length of frost-free period were key indicators to phenotypic of A. pedunculata in different site conditions. According to principal component analysis and unweighted pair-group method with arithmetic means (UPGMA) cluster analysis, the seven populations of A. pedunculata could be divided into two groups. In mountainous region, A. pedunculata’s leaf blade was usually rotund to oblong, fruit nearly spherical shape with shorter fruit stem, stone was usually ovoid to spherical shape. In contrast, in sandy region, leaf blade was long oval to ovate-lanceolate, fruit and stone was usually flat ovoid with longer fruit stem. Our results provide critical information for the resource collection and breeding of this ecologically important species.     

Vegetative growth and leaf resin composition in Hymenaea courbaril under photoperiodic extremes

Seedlings from five geographic populations of the widespread Hymenaea courbaril were grown for one year under two extremes of photoperiod. The short photoperiod treatment consisted of 8 hr of unsupplemented greenhouse daylight and the long photoperiod treatment of greenhouse daylight at the natural photoperiod of Santa Cruz, California (37° N) plus a 3-hr night interruption (0.25 mW/cm²). Growth was measured by total stem length and leaf resin sesquiterpene composition was quantitatively analyzed by GLC. Photoperiod had no significant effect on leaf resin chemistry but the longer photoperiod markedly promoted vegetative growth. Large population differences in overall vegetative growth and quantitative leaf resin composition were also evident. Growth patterns indicated that the low intensity night break had little or no effect on growth.     

Chemotaxonomic significance of flavonoids and phenolic acids in the Hieracium rohacsense group (Hieracium sect. Alpina; Lactuceae, Compositae)

Five apomictic taxa from the Hieracium rohacsense group were studied for their phenolic constituent composition. The following substances represent dominant compounds in the leaves: chlorogenic acid, 3,5-dicaffeoylquinic acid, luteolin 7-O-β- -glucopyranoside, luteolin 4′-O-β- -glucuronopyranoside and apigenin 4′-O-β- -glucuronopyranoside. Within the group only quantitative differences were found, luteolin 7-O-glucoside being the most important chemotaxonomic marker. Each taxon has its own specific quantitative pattern, invariable within the taxon. Based on these characteristic profiles, H. rohacsense can be distinguished from a closely related and still undescribed taxon from Mt. Pip Ivan. The proportion of luteolin 7-O-glucoside to apigenin 4′-O-glucuronoside also clearly separates the individuals of two morphologically close species—H. ratezaticum and H. pseudocaesium, which corresponds to a few slight but recognisable morphological and phenological characteristics. The ontogenetic stage of leaf development and seasonal variation are also important factors, which must be taken into consideration, as the quantity of the substances changes during leaf ontogeny and with season.     

Intra- and interplant leaf sesquiterpene variability in Copaifera langsdorfii: relation to microlepidopteran herbivory

Oecophorid herbivory in Copaifera langsdorfii leaves along with sesquiterpene composition, concentration of most of the individual sesquiterpenes and total yield did not significantly differ between the lower and upper portions of tree canopies. Although sesquiterpene variation in leaves collected throughout individual tree canopies was less than variation among trees, leaves which were eaten by oecophorid larvae had slightly lower yields than those unattacked. Individual C. langsdorfii trees within the population were significantly different from one another in sesquiterpene yield, oecophorid herbivory and in the concentration of seven out of the 11 sesquiterpene compounds. Leaf sesquiterpenes appear to be more important in inhibiting herbivory by Stenoma aff. assignata than leaf moisture and nitrogen content and toughness.     

基于COI和ND5序列的中国南部唇鱼骨和间鱼骨群体遗传结构

唇鱼骨和间鱼骨均为分布较广的初级淡水鱼类,是理想的亲缘地理研究材料;且两者形态特征较为相似,不易鉴别,故两者的分布记述和物种有效性存在争议.为了解我国南部唇鱼骨和间鱼骨的群体遗传结构并探讨两者的物种有效性,本研究对8条水系的唇鱼骨和9条水系的间鱼骨共130尾个体的COI和ND5基因序列片段进行了测定,并对这两个基因的组合序列(2151 bp)进行了分析.结果表明: 在130尾个体的COI和ND5基因组合序列中,共有196个核苷酸变异位点,共检测出50个单倍型,单倍型多样性为0.964,核苷酸多样性为0.019,遗传多样性较高.基于COI和ND5基因组合序列构建的 NJ 树显示,所有种群可分为两支,支系Ⅰ包含了韩江和九龙江的全部单倍型以及瓯江的部分单倍型,余下的单倍型组成了支系Ⅱ.两支系间的遗传距离为0.036,而唇鱼骨与间鱼骨之间的遗传距离为0.027.单倍型网络图表明,韩江、九龙江种群和其他水系种群分化较大;漠阳江种群由海南岛种群扩散而来;海南岛各种群及漠阳江种群的单倍型分支与珠江水系单倍型的分支之间的亲缘关系较近,与长江水系单倍型分支之间的亲缘关系则较远;湘江、桂江和柳江之间的亲缘关系较近.AMOVA分析结果显示,地理区之间的变异约占71.2%,地理区内种群间变异约占16.6%,种群内的变异占12.2%,表明其遗传分化主要来自地理区之间.错配分析及中性检验结果显示,全部种群、唇鱼骨种群、间鱼骨种群、支系Ⅰ和支系Ⅱ在历史上均没有发生过明显的扩张.     

基于COI和ND5序列的中国南部唇鱼骨和间鱼骨群体遗传结构

唇鱼骨和间鱼骨均为分布较广的初级淡水鱼类,是理想的亲缘地理研究材料;且两者形态特征较为相似,不易鉴别,故两者的分布记述和物种有效性存在争议.为了解我国南部唇鱼骨和间鱼骨的群体遗传结构并探讨两者的物种有效性,本研究对8条水系的唇鱼骨和9条水系的间鱼骨共130尾个体的COI和ND5基因序列片段进行了测定,并对这两个基因的组合序列(2151 bp)进行了分析.结果表明: 在130尾个体的COI和ND5基因组合序列中,共有196个核苷酸变异位点,共检测出50个单倍型,单倍型多样性为0.964,核苷酸多样性为0.019,遗传多样性较高.基于COI和ND5基因组合序列构建的 NJ 树显示,所有种群可分为两支,支系Ⅰ包含了韩江和九龙江的全部单倍型以及瓯江的部分单倍型,余下的单倍型组成了支系Ⅱ.两支系间的遗传距离为0.036,而唇鱼骨与间鱼骨之间的遗传距离为0.027.单倍型网络图表明,韩江、九龙江种群和其他水系种群分化较大;漠阳江种群由海南岛种群扩散而来;海南岛各种群及漠阳江种群的单倍型分支与珠江水系单倍型的分支之间的亲缘关系较近,与长江水系单倍型分支之间的亲缘关系则较远;湘江、桂江和柳江之间的亲缘关系较近.AMOVA分析结果显示,地理区之间的变异约占71.2%,地理区内种群间变异约占16.6%,种群内的变异占12.2%,表明其遗传分化主要来自地理区之间.错配分析及中性检验结果显示,全部种群、唇鱼骨种群、间鱼骨种群、支系Ⅰ和支系Ⅱ在历史上均没有发生过明显的扩张.     

Pseudohypericin and hyperforin in two Turkish Hypericum species: Variation among plant parts and phenological stages

The genus Hypericum has received considerable interest from scientists, as it contains the variety of structurally diverse natural products which possess a wide array of biological properties, mainly hypericins and hyperforin. In the present study, variations of pseudohypericin and hyperforin were investigated in two Turkish species of Hypericum, namely Hypericum perfoliatum and Hypericum origanifolium. Wild growing plants were harvested at vegetative, floral budding, flowering, fresh fruiting and mature fruiting stages, and dissected into stem, leaf and reproductive tissues and assayed for chemical contents by high performance liquid chromatography method. Content of pseudohypericin and hyperforin in samples of the whole plant increased during the course of ontogenesis in both species. The highest levels of the chemicals were reached at full flowering (2.62 mg/g dry weight (DW) pseudohypericin and 1.84 mg/g DW hyperforin for H. perfoliatum; 0.93 mg/g DW pseudohypericin and 1.63 mg/g DW hyperforin for H. origanifolium). Among different reproductive parts, full opened flowers produced the highest amount of pseudohypericin (1.18 mg/g DW) and hyperforin (4.36 mg/g DW) in H. origanifolium. Similarly, the highest pseudohypericin accumulation was observed in full opened flowers in H. perfoliatum (7.41 mg/g DW) while floral buds of this species produced the highest amount of hyperforin (7.80 mg/g DW). These data can be useful when elucidating the medicinal properties of the species and the chemosystematic significance of hyperforin and pseudohypericin in the relationships among species of Hypericum.     

Variation in leaf resin composition between parent tree and progeny in Hymenaea: Implications for herbivory in the humid tropics

Variation in the sesquiterpene hydrocarbon leaf resins in the tropical leguminous genus Hymenaea is compared between parent tree, seedling and sapling progeny. Relatively large discrete quantitative variation in the leaf resins, known experimentally to display little phenotypic plasticity, has been classified into Compositional Types. Differences in Compositional Types in the leaves between parent tree and their seedling and sapling progeny are more pronounced in rain forest and related eocystems than in savanna and dry forests. A model is presented in which it is suggested that this variation in leaf resin may play an important role in defence against lepidopteran herbivores and thus also in seedling establishment under Hymenaea parent trees in rain forest and related ecosystems.     

Quantitative variation within and among populations of Arabis serrata Fr. & Sav. (Brassicaceae)

Phenotypic and genetic variation within and among eight populations of Arabis serrata are documented in this study. This species shows great morphological variation throughout its geographical distribution in Japan. Plants are located in habitats with different types of soils and degree of disturbance. Half-sibs progenies from eight populations were collected and cultivated in a garden experiment. Nine morphological traits representing size and shape of rosette leaves were recorded. Univariate analyses of measured traits showed that phenotypic means differed among populations for all characters. Leaves of plants from disturbed habitats had the longest petioles (lanceolate) and plants from limestone habitats showed the most roundness in leaf shape (ovate). The northernmost populations always revealed the smallest leaves. Multivariate principal component analyses also showed that leaf shape and size varied among populations. The first three principal components explained 98.5% of the variation. Coefficients of variation had a very wide range and differed from one population to another. Some traits (e.g. leaf width/leaf length ratio) were consistently less variable while others (e.g. leaf area and petiole length) were more plastic. All traits had significant genetic variance in all populations. Intra-class correlation coefficients differed for most of the traits and each population presented a different range of values. Most of the leaf traits were intercorrelated in all the populations studied, although some populations were integrated more tightly for some traits. Populations of A. serrata are differentiated in phenotypic means but they display a mosaic of traits with slight morphological differences in each locality (i.e. a quantitative genetic variation). Some traits can be correlated to the habitats that they occupy but for some of them it is difficult to assign an actual adaptive value.     

Geographical variation in the monoterpenes of Valeriana officinalis Leaf

The variation in terpene composition of the leaf essential oil was studied in three populations of Valeriana officinalis L. subsp, collina. These populations grow in Italy in environmentally very different areas. Our examination of geographically and ecologically distant populations has provided evidence for substantial Iocal intrasubspecific differentiation. Statistical treatment of chemical data revealed two distinct chemical varieties of subspecies collina.     

Within-tree spatial variation in the leaf monoterpenes of Sequoia sempervirens

Location within a tree was analyzed as a source of variation in Sequoia sempervirens leaf monoterpenes. No differences were found for quantitative composition or total yield/dry wt among lower, middle and upper canopy positions. The awlshaped, spirally arranged leaves of vigorous upper shoots showed small quantitative compositional differences, but not differences in total yield. The intermediate leaf form of young sprouts had the most different monoterpene quantitative composition and about three times the total yield of the above two leaf forms. Analysis of a clonal ring of 17 adult trees resulted in coefficients of variation similar to those for samples collected from different canopy levels of the same shoot. Results revealed the sources and magnitudes of experimental error in comparative studies of this species' leaf monoterpenes, and did not support the concept that somatic mutation provides an important source of variation in a large, long-lived organism such as coast redwood.     

Chemosystematic Investigation of the Annual Species of Helianthus (Asteraceae)

A total of 43 HPLC peaks tentatively considered to be sesquiterpene lactones was detected from a survey of the 18 taxa (eleven species and seven subspecies) of Helianthus sect. Helianthus using a recently developed microtechnique. All but one of the taxa showed characteristic sesquiterpene lactone patterns with between six and 15 compounds each. H. paradoxus appears to be the only species in the genus in which these compounds are not detectable. Comparison with available reference compounds allowed assignment of structures to 21 of the compounds. Known compounds can be classified into five major structural subtypes, the systematic distribution of which divides the section into three well-defined subgroups. The sesquiterpene lactone profiles of the other two annual species of the genus, H. agrestis and H. porteri, exhibit significant differences relative to any species of sect. Helianthus, which supports their exclusion from the section.     

小叶锦鸡儿天然居群叶形态性状变异研究

为揭示小叶锦鸡儿(Caragana microphylla)天然居群叶形态性状的变异规律及其生态适应性特征,该研究以10个小叶锦鸡儿天然居群为对象,通过多重比较、巢式方差分析、相关性分析、聚类分析和主成分分析等方法,对7个叶形态性状进行分析。结果表明：(1)小叶锦鸡儿叶形态性状在居群内和居群间均存在极显著差异(P < 0.01),平均变异系数为10.13%,不同性状的变异幅度为6.23%~12.78%;平均叶形态性状的表型分化系数为43.62%,居群内变异(30.09%)大于居群间变异(24.91%),说明居群内是其叶形态性状变异的主要来源。(2)相关性分析表明,环境因子对小叶锦鸡儿的叶形态性状变异有很大的影响,在地理空间上主要呈现出沿海拔梯度的变异模式;主成分分析的结果显示,小叶宽、叶柄宽和叶柄长对小叶锦鸡儿叶形态变异起主导作用;利用欧式距离对小叶锦鸡儿居群进行UPGMA聚类分析结果显示,基于叶形态性状和环境因子可分别将小叶锦鸡儿10个居群分为3类和2类,Mantel检验结果表明,小叶锦鸡儿的叶形态性状变异不存在地理连续性。研究结果为小叶锦鸡儿的适应性进化和开发利用提供了理论依据。     

Comparative genetic mutation frequencies based on amino acid composition differences

Genetic variation inferred from large-scale amino acid composition comparisons among genomes and chromosomes of several species, Saccharomyces cerevisiae, Drosophila melanogaster, Ceanorhabditis elegans, H. sapiens, is shown to be correlated (highest, r² = 0.9855, p < 0.01) with reported mutation rates for various genes in these species. This study, based largely on pseudogene data, helps to establish reference mutation frequencies that are likely to be representative of overall genome mutation rates in each of the species examined, and provides further insight into heterogeneity of mutation rates among genomes.     

Flavonoids of Helianthus series Microcephali

Ray flower and leaf flavonoids were investigated for the three species of Helianthus series Microcephali. Ray flowers of all species contain coreopsin, sulphurein, and quercetin 7-O-glucoside; those of H. microcephalus also contain quercetin 3-O-glucoside. A mixture of flavonoid aglycones, mostly methoxylated flavones, occurs in leaves of H. microcephalus, but not in H. glaucophyllus or H. laevigatus which also lack the glandular trichomes that in Helianthus are typically associated with flavonoid aglycones. The presence of compounds with the 6,8,4′ pattern of methoxylation in H. microcephalus suggests that the series is more similar in flavonoids to series Angustifolii than to series Corona-solis.     

Genetic variation in Haworthia pumila and H. herbacea

Horizontal starch gel electrophoresis was used to examine genetic diversity within and differences between one population each of two morphologically different species of Haworthia, namely H. pumila and H. herbacea. Twenty-five leaf samples of each species were surveyed for 24 proteins of which 13 were useful for routine analysis, and gene products of 16 protein coding loci revealed genetic variation at 7 (43.8%) thereof in both species. Values of 1.63 (± 0.20) and 1.56 (± 0.18) were obtained for the mean number of alleles per locus and the average heterozygosity per locus was calculated at 0.168 (± 0.058) and 0.144 (± 0.048) for H. herbacea and H. pumila respectively. The malate dehydrogenase-2 locus is a potential genetic marker to identify the species studied electrophoretically. The mean genotypic distance index between the populations studied was 0.184, an indication of large degree of differentiation between the species. These values are much higher than values obtained for other members of the Aloaceae, showing that normal levels of genetic variation can be expected in at least some succulent monocotyledons.     

Ultrastructural studies on experimental primary amoebic meningo-encephalitis (PAME) of mouse due to Naegler1a aerobia and Hartmannella culbertsoni

Primary amoebic meningo-encephalitis (PAME) in mouse can be easily produced by intranasal inoculation of Naegleria aerobia Singh & Das, 1970 and Hartmannella culbertsoni Singh & Das, 1970. The ultrastructural characteristics of N. aerobia and H. culbertsoni from infected mouse brain tissues showed many similar characteristics. The distinctive features between the two were the retention of phagocytic activity by N. aerobia as well as pinocytic activity in the ingestion of food as compared to H. culbertsoni where only pinocytic activity was observed. Staining characteristics of mitochondria suggested that N. aerobia was more active in the brain tissues than H. culbertsoni. Membrane-bound darkly stained bodies of unknown function were found in the brains infected with both N. aerobia and H. culbertsoni. They may have some bearing on the pathogenicity of these amoebae. Human cases of PAME so far reported are mostly due to N. aerobia and rarely with H. culbertsoni. This may be due to certain inherent characteristics present in N. aerobia which help them to survive on human brain tissue. On the other hand, the same may be lacking in H. culbertsoni. These ultrastructural differences in both N. aerobia and H. culbertsoni, as revealed by electron microscope studies of the infected brain tissues of mice, are presented in this paper.