胡椒属化学成分的研究

本文对胡椒属植物生物碱和黄酮等类化学成分及其生物活性的研究进行了综述。     

INFLORESCENCE AND FLOWER DEVELOPMENT IN THE PIPERACEAE. II. INFLORESCENCE DEVELOPMENT OF PIPER

The inflorescence development of three species of Piper (P. aduncum, P. amalago, and P. marginatum), representing Sections Artanthe and Ottonia, was studied. The spicate inflorescences contain hundreds or even thousands of flowers, depending on the species. Each flower has a tricarpellate syncarpous gynoecium and 4 to 6 free stamens, in the species studied. No sepals or petals are present. In P. marginatum the apical meristem of the inflorescence is zonate in configuration and is unusually elongate: up to 1,170 μm high and up to 480 μm wide during the most active period of organogenesis. Toward the time of apical cessation both height and diameter gradually diminish, leaving an apical residuum which may become an attenuate spine or may be cut off by an abscission zone just below the meristem. The active apex produces bract primordia; when each is 40–55 μm high, a floral apex is initiated in its axil. Both bract and floral apex are initiated by periclinal divisions in cells of the subsurface layer. The bracts undergo differentiation rather early, while the floral apices are still developing. The last-produced bracts near the tip of the inflorescence tend to be sterile.     

ANATOMICAL AND ULTRASTRUCTURAL ASPECTS OF THE ANT-FOOD CELL OF PIPER CENOCLADUM C.DC. (PIPERACEAE)

Piper cenocladium is a common understory species in the wet primary forested areas of Costa Rica. The plant possesses a petiole chamber which is usually occupied by the ant Pheidole bicornis. The plant/ant relationship is unique in that the ant must be present for meaningful numbers of ant-food bodies to be differentiated. The food body is a lipid storing, single cell developed from one adaxial petiole epidermal cell. Cellular aspects of this differentiation process are described with particular reference to nucleolar ultrastructure.     

GENOTYPIC AND ENVIRONMENTAL COMPONENTS OF VARIATION IN GROWTH AND REPRODUCTION OF FISH HEMICLONES (POECILIOPSIS: POECILIIDAE)

The frozen-niche-variation model was proposed to account for the coexistence of genetically related clones in naturally occurring unisexual populations. This model is based on two assumptions: 1) ecologically different clones have multiple independent origins from sexual ancestors; and 2) the population of sexual ancestors contains genetic variability for ecologically relevant traits. To test these assumptions, we produced 14 new “hemiclones” (nonrecombining haploid genotypes) of fish (Poeciliopsis: Poeciliidae). Our ability to synthesize many new hemiclones demonstrates the feasibility of multiple independent origins of nonrecombining genotypes. A substantial proportion (10–50%) of the phenotypic variation among hemiclones in size at birth, juvenile growth rate, and fecundity had a genetic basis. Thus, we conclude that multiple origins can give rise to an assemblage of genetically distinct hemiclones, each with a unique combination of life-history traits. Additionally, a comparative analysis of two natural hemiclones revealed that the synthetic strains represent a broad field of variation from which natural hemiclones can be selected.     

GENOTYPIC VARIATION AND INTEGRATION IN HISTOLOGICAL FEATURES OF THE GOLDENROD BALL GALL

The herb Solidago altissima (Compositae) forms a gall when attacked by the fly Eurosta solidaginis (Diptera: Tephritidae). We performed an experiment to determine how histological features of gall morphology contribute to previously observed genetic variation in gall diameter. Galls induced on 10 replicated plant clones were sectioned, and their internal tissues and cells measured. Four concentric tissue zones were identified, including a cytoplasmically rich tissue lining the insect's central chamber, and a cytoplasmically poor cortex. As expected, outer gall diameter differed among clones, with a broad sense heritability of 0.29. However, clonal differences for component tissue thicknesses were found for only two of the zones; cortex thickness showed the greater genotypic variation, with a broad sense heritability of 0.30. Path analysis was used to examine the contribution of the zone thicknesses, vascular supply and cell sizes to outer gall diameter at the phenotypic, genotypic and environmental-developmental levels. These showed that cortex thickness was the single greatest determinant of gall size. At the phenotypic level, the single most important determinant of cortex thickness was the number of cortical cells, whereas the amount of cortical vascularization was second in importance. But, at the genotypic level of analysis, vascularization was the single most important determinant of genotypic differences in gall size. The larger the gall, the greater the protection to the inducing insect. Since the bulk of the gall consists of large, cytoplasmically poor cells, the insect gains protection while imposing a small cost on the plant.     

DETECTING SHAPE VARIATION IN OAK LEAF MORPHOLOGY: A COMPARISON OF ROTATIONAL-FIT METHODS

Rotational-fit methods were used to examine shape variation in oak leaf morphology by reference to a set of 14 landmarks for each leaf. Within-tree, between-tree, and between-species variations were examined. Generalized least-squares and generalized resistant-fit analyses revealed patterns of landmark variation that could be related to leaf architecture. The two species (Quercus palustris and Q. velutina) did not illustrate the same patterns of within-tree variability nor did they reveal similar degrees of between-tree variability. Incorporating an affine transformation algorithm resulted in little insight in some comparisons but suggested strong uniform shape change in other comparisons (especially between species). Resistant-fit mean square statistics were equally variable 1) in upper vs. lower crown samples within trees, 2) between trees within each species, and 3) between species. In addition, resistant-fit mean square statistics were found to be a poor measure of similarity, whether derived by comparison to a single reference object or by way of pairwise comparisons. Fundamental species differences in leaf shape are suggested by relationships among particular sets of landmarks, although overall shape differences cannot be explained fully by these analyses.     

POSITIONAL AND SEASONAL VARIATION IN OAK (QUERCUS; FAGACEAE) LEAF MORPHOLOGY

Within-tree and seasonal variation in quantitative characters of oak leaves were evaluated by factorial analysis of variance. All linear and areal measurements illustrate marked within-tree and seasonal variation. Numbers of lobes and bristle tips and primary vein angle appear relatively stable within trees and among seasons. In many instances, size-correction reduces both within-tree and seasonal variance to nonsignificant levels. However, all characters do not illustrate the same trends either within trees or across the seasons. The results have important implications for those attempting to evaluate among-tree and among-population variation.     

VARIATION IN LEAF DISSECTION AND LEAF ENERGY BUDGETS AMONG POPULATIONS OF ACHILLEA FROM AN ALTITUDINAL GRADIENT

The degree of leaf dissection differs dramatically among populations of the Achillea millefolium complex along an altitudinal gradient in the Sierra Nevada. The purpose of this study was to determine whether there was a genetic basis to differences in leaf shape among populations, and also to determine the importance of genetic variability within populations, plastic responses of leaf shape to the growth environment, and genetic differences among populations in plastic response to the environment. A second major goal of the research was to investigate the effects of differences in leaf dissection on the capacity for leaf temperatures to become uncoupled from air temperatures. Greenhouse experiments using clonal replicates of plants collected at different altitudes revealed that there were genetic differences among populations in the degree of dissection, and that other sources of phenotypic variation, such as plasticity, were also significant. Leaves from the highest altitude population had the most compact shape under all conditions, while those from lower altitude populations were always more open and highly dissected. In both simulations and actual measurements the dissected leaves of low altitude plants remained close to air temperatures, while the compact leaves of high altitude plants had the capacity to warm up substantially above air temperatures.     

VARIATION IN ENVIRONMENTAL AND GENOTYPIC SEX-DETERMINING MECHANISMS ACROSS A LATITUDINAL GRADIENT IN THE FISH,MENIDIA MENIDIA

Models of environmental sex determination (ESD) usually assume that genetic influences on sex are polygenic, but the validity of this (or any other) form of genotype-environment interaction is virtually unknown. In the Atlantic silverside, Menidia menidia, sex is determined by an interaction between temperature and genotype and the response of sex ratio to temperature differs among populations from different latitudes. We examined the genetic basis of this pattern by measuring among family variation in the proportion of females, F/(F + M), within and among high (21°C) and low (15°C) temperatures for two populations: one from Nova Scotia (NS) where the level of ESD is low, and another from South Carolina (SC) where the level of ESD is high. In NS fish, temperature had a significant influence on sex ratio in only 1 of 23 families. The distribution of the fraction of females within temperatures for families from NS was highly heterogeneous and tended to fall into distinct classes (0.0, 0.25, 0.5, 1.0) like that expected from Mendelian segregation of a major sex factor(s). In contrast, temperature had a highly significant influence on sex ratio in all SC families examined (N = 24). Family sex ratios within temperatures were highly heterogeneous and, at least at 15°C, did not conform to simple Mendelian ratios. At 21°C, the proportion of females in most SC families was near zero and so the underlying sex tendencies of different families could not be discerned. Based on a previous study, mid-latitude fish appear to have an intermediate form of sex determination: simple Mendelian sex-ratio patterns exist and there is a moderate thermal influence on sex ratio in most but not all families. We suggest that sex determination in M. menidia is controlled by an interaction between major genetic factors, polygenic factors, and temperature and that the relative importance of each component differs with latitude. High latitude populations appear to have evolved a major sex-determining factor(s) that overrides the effect of temperature, and this factor(s) is lacking in low latitude populations.     

HYMENAEA和COPAIFERA幼树叶内倍半萜类化合物昼夜和季节性变化

运用气相色谱对在温室栽培的Hymenaea courbaril和Copaifera officinalis及C. pubiflora幼树叶内倍半萜类化合物昼夜和季节性变化进行了分析测定。Hymenaea和Copaifera这二个属植物叶内具有基本相同的一组倍半萜类化合物,对认为具有生态意义的它的主要成分:石竹烯(caryophyllene),α,β-瑟林烯(selinene)和树脂含量进行了分析统计。在三个季节和昼夜的资料中,这二个属植物的石竹烯、α,β-瑟林烯和树脂含量昼夜变化是很小的,而在植株间(遗传型)和不同的季节里它们有明显而有意义的变化。     

GENOTYPIC VARIATION AND ALTERNATING DNA LEVELS AT CONSTANT CHROMOSOME NUMBERS IN THE LIFE HISTORY OF THE BROWN ALGA HAPLOSPORA GLOBOSA (TILOPTERIDALES)1

The brown algal order Tilopteridales contains three monospecific genera with reduced life histories, Which are assumed to have been derived form ancestors with oogamous reproduction and alternation of generations. The Newfoundland population of Haplospora globosa Kjellman still shows an alternation of gametophytes and sporophytes, but the chromosome Numbers remain equal because of parthenogenesis and apomeiosis, However, DNA fluorometry showed that the DNA level is twice as high in the Sporophytes as in the gametophytes, The DNA variation at constant chromosome numbers is presumably due to endomitosis combined with a law degree of polyteny. A genotypic variant of Haplospora is represented by the population at Helgoland (F.R.G.) where only sporophytes exist, Spores develop into sporophytes instead of gametophytes, and the plants have reduced chromosome number but the same DNA level as the Newfoundland sporophytes     

ADAPTATION TO SEASONALITY IN A CRICKET: PATTERNS OF PHENOTYPIC AND GENOTYPIC VARIATION IN BODY SIZE AND DIAPAUSE EXPRESSION ALONG A CLINE IN SEASON LENGTH

This paper investigates patterns of phenotypic variation in the striped ground cricket (Allonemobious fasciatus) along a cline in season length and tests the hypothesis that variation in body size and diapause propensity is the result of diversifying selection due to different local conditions. We examined 83 populations and found that A. fasciatus produced a single generation per year (univoltine) north of 37°N latitude and was bivoltine south of 35°30′N. Body size generally increased with increasing season length, with a sudden drop in the region corresponding to the transition from univoltine to bivoltine life cycles, reflecting the division of total season length in two within-bivoltine populations. We reared ten populations in our laboratory and found that much of the interpopulation variance in body size observed in the field could be attributed to genetic differences. Diapause expression also varied significantly among populations and was strongly correlated with season length. The heritability of body size did not differ between populations, but full-sib estimates greatly exceeded parent–offspring estimates suggesting that there are important nonadditive genetic effects. The heritability of diapause expression, determined from analysis of full sibs, varied significantly between populations (0.33 ± 0.10 to 1.31 ± 0.21) with an average of 0.74 ± 0.16. Body size and diapause expression were genetically correlated in transition-zone populations, but not in univoltine or bivoltine populations. Our findings support the suggestion that clinal variation in body size and diapause expression in the striped ground cricket reflect adaptation to season length.     

OCCURRENCE OF A FAR-RED-ABSORBING PIGMENT (P 715) IN LEAF EXTRACT OF GYNKGO BILOBA

The occasional occurrence of far-red-absorption band in thegreen extract of Gynkgo biloba leaves was noticed. It resultedfrom the conversion of the ordinary red-absorbing form of thechlorophyllous pigments with absorption maximum at 675 mµ(P 675), to the far-red-absorbing form with absorption maximumat 710–715 mµ (P 715). The conversion seems to takeplace in two steps, i.e., first, decrease in thered-absorptionband, and secondly, appearance of the far-red-absorption band.Under some experimental conditions, the latter step occurs onlyafter a certain time lag. The conversion is accompanied by thechangeof chlorophylls a and b, contained in the initial formof the pigment, P 675, to the pheophytins and pheophorbides.The properties of the far-red-absorbing pigment are differentfrom those of other chlorophyllous pigments discovered in otherplant materials. ( Accepted January 29, 1965)     

ORIGINS OF GENOTYPIC VARIATION IN NORTH AMERICAN DANDELIONS INFERRED FROM RIBOSOMAL DNA AND CHLOROPLAST DNA RESTRICTION ENZYME ANALYSIS

Restriction enzyme analysis of ribosomal DNA (rDNA) and chloroplast DNA (cpDNA) is used to assess the relative contribution of hybridization and mutation as sources of genotypic variation in weedy asexual dandelions, with focus on the dandelion flora of North America. Of 318 North American dandelions surveyed, 145 rDNA-cpDNA clones are detected. The combined rDNA-cpDNA genotypes show that most of the polymorphic rDNA and cpDNA restriction sites or lengths in these plants are also present in weedy asexual dandelions collected from natural populations in Europe and in asexual and diploid taxa (microspecies) chosen to represent diverse Eurasian members of the genus. However, of 222 combined rDNA-cpDNA genotypes found in 427 asexual plants surveyed, only 9 genotypes are found in both North American and Eurasian dandelions. Two rDNA and three cpDNA characters are unique to individual plants in North America and are consistent with mutational origins of genotypic variation in asexual lineages. But the array of genotypic diversity, characterized by different combinations of the rDNA and cpDNA characters, show that multiple hybridization events are a more important source of genotypic variation than mutation in the asexual polyploids. The rDNA and cpDNA data also indicate polyphyletic origin of several asexual Taraxacum taxa.