共查询到20条相似文献,搜索用时 15 毫秒
1.
Four species of Nyssa, eleven species of Cornus, and one species each of Davidia, Camptotheca, Aucuba, and Mastixia were analyzed for seed oil fatty acids. Canonical variates calculated from percentage palmitic stearic, oleic, linoleic and linolenic acids show that Nyssa biflora lies intermediate to N. sylvatica and N. aquatica in composition. Davidia involucrata should remain allied with the Nyssaceae. Many of the Cornus species from several subgenera comprise a single cluster that represents a fatty acid composition at or near the primitive condition. 相似文献
2.
Previous proposals for subdivision of the genus Cornus are reviewed. Twenty-seven authenticated Cornus species have been studied for their content of non-flavonoid glucosides. Two distinct groups of taxa can be distinguished on this basis: one, containing a hydroxycyclohexadienone glucoside, along with salidroside, its reduced counterpart, and the second, characterized by containing various iridoid glucosides. The two types of glucosides are apparently mutually exclusive. 相似文献
3.
All species of Galeopsis contain aucubin-like glycosides in roots, leaves and seeds. Acetylharpagide is typical of leaves of the species of the subgenus Ladanum and galiridoside characterizes leaves of taxa of the subgenus Tetrahit. However, the leaves of Galeopsis pubescens, G. segetum and G. pyrenaica contain appreciable amounts of both constituents. In roots and seeds, the difference between the two subgenera is less striking. However, roots of species of subgenus Tetrahit are characterized by a third constituent, called bifida-substance. Some chemical characters of Galeopsis are discussed and evaluated systematically. Galeopsis resembles Lamiastrum in leaf aucubinoids. 相似文献
4.
The flavonoids of the Tiarella trifoliata L. complex consists of kaempferol, quercetin and myricetin-3-O-mono-, di- and triglycosides, kaempferol and quercetin-7-O-monoglycosides, kaempferol-3,7-O-monoglycosides and luteolin. Infrapopulationa and interpopulational variations were seen in the distribution of several of these types of compounds. The flavonoid data do not support recognition of separate species for the three taxa. 相似文献
5.
描述并厘定了黑龙江省嘉荫县古新世乌云植物群中的广义山茱萸科绝灭类型镘形美中果 (Amersiniaobtrul lataManchester,CraneetGolovneva)和假古老白令叶 (Beringiaphyllumpseudoantiquum (Golovneva)Manchester,CraneetGolovneva)。将前人鉴定为昆栏树属 (未定种 ) (Trochodendronsp .)的果序化石归入镘形美中果 ;将前人确定为鲜艳杨 (Populuscarneosa)、假原始叶南蛇藤 (Celastrophyllumsubprotophyllum)、古老荚 (Viburnumantiquum)、粗糙荚 (V .asperum)、疏齿荚叶 (Viburniphyllumfinale)、乌云原始叶 (Potophyllumwuyunense)、海丹原始叶 (近似种 ) (P .cf.hay denii)、卵圆原始叶 (P .ovatifolium)和不规则克里木 (Credneriainordinata)等归入假古老白令叶 相似文献
6.
描述并厘定了黑龙江省嘉荫县古新世乌云植物群中的广义山茱萸科绝灭类型镘形美中果(Amersinia obtrullata Manchester, Crane et Golovneva)和假古老白令叶(Beringiaphyllum pseudoantiquum (Golovneva) Manchester, Crane et Golovneva).将前人鉴定为昆栏树属(未定种)(Trochodendron sp.)的果序化石归入镘形美中果;将前人确定为鲜艳杨(Populus carneosa)、假原始叶南蛇藤(Celastrophyllum subprotophyllum)、古老荚(Viburnum antiquum)、粗糙荚(V. asperum)、疏齿荚叶(Viburniphyllum finale)、乌云原始叶(Potophyllum wuyunense)、海丹原始叶(近似种)(P. cf. haydenii)、卵圆原始叶(P. ovatifolium)和不规则克里木(Credneria inordinata)等归入假古老白令叶. 相似文献
7.
Eight species of Saxifraga representing sections Micranthes, Hirculus, Dactyloides and Xanthizoon were studied for their flavonoids (S. california, S. integrifolia, S. michauxii, S. ferruginea, S. eschscholtzii, S. hirculus, S. caespitosa and S. aizoides). The major compounds present in most species were kaempferol and quercetin monogluocosides and galactosides. Glucosides of kaempferol and quercetin predominate in the first four species listed, while galactosides of quercetin and myricetin are dominant in the lastthree. 3-O-Methyl- and 3,3′-di-O-methylquercetin were identified from S. californica and S. integrifolia. Saxifraga caespitosa synthesizes a complex mixture of O-methylated flavonols as well as a novel O-methylated dihydrokaempferol.Species pairs S. michauxii/S. ferruginea and S. californica/S.integrifolia exhibit close flavonoid similarity which may reflect their morphological similarities. 相似文献
8.
? Premise of the study: Microsatellite markers were developed for the dove tree, Davidia involucrata (Cornaceae), a Tertiary relict currently endemic to China, to investigate its population genetics and phylogeography. ? Methods and Results: Using the Fast Isolation by AFLP of Sequences Containing repeats (FIASCO) protocol, nine polymorphic microsatellite loci were identified and screened in 44 individuals from three wild populations of D. involucrata. The number of alleles per locus ranged from two to three, while the observed heterozygosity and expected heterozygosity ranged from 0.0000 to 0.6000 and from 0.0000 to 0.6323, respectively. ? Conclusions: These new microsatellite loci will facilitate further studies of the population genetics and phylogeography of D. involucrata, as well as of the evolutionary history of the plant and other Tertiary relicts endemic to East Asia. 相似文献
9.
? Premise of the study: The first microsatellite primers were developed for Davidia involucrata, an endangered relic species of the Tertiary in China, to further describe its genetic variability and population structure. ? Methods and Results: Using the Fast Isolation by AFLP of Sequences Containing Repeats (FIASCO) protocol, 15 polymorphic microsatellite loci were isolated and characterized in 20 individuals from the germplasm collections of D. involucrata at the Hunan Forest Botanical Garden. High levels of polymorphism were revealed, with the total number of alleles per locus and the number of alleles per locus per individual ranging from two to 13 and from one to six, respectively. ? Conclusions: The multibanded patterns of microsatellite loci obtained in the current study confirmed that D. involucrata might be a polyploid species. The primers will be useful for studies of genetic diversity and for guiding conservation strategies for D. involucrata. 相似文献
10.
11.
12.
13.
Five Hieracium species were examined for flavonoid constituents: H. albertinum, H. albiflorum, H. cynoglossoides, H. gracile and H. umbellatum. The major compounds present in all species were mono- and diglycosides, of apigenin and luteolin. Chrysoeriol occurred per se in several species. Quercetin-3-O-glucoside was seen only in H. umbellatum. Species specific patterns of flavonoid glycosides were evident in all five taxa; H. albertinum and H. cynoglossoides showed the greatest similarity which reflects their morphological similarity. Limited examination of artificial hybrids showed additivity of flavonoid glycoside patterns. 相似文献
14.
From three of five investigated species of Griselinia a new iridoid glucoside, griselinoside, was isolated. It was found to be present also in foliage of Aralidium pinnatifidum and Toricellia angulata, accompanied in the former by aralidioside another novel iridoid glucoside. The structures and absolute configurations of the two iridoids were elucidated by NMR spectroscopy and chemical conversions. From G. littoralis and T. angulata the glucosides magnolioside and syringoside respectively were isolated. 13C NMR spectra are given for thirteen iridoid derivatives. 相似文献
15.
Computer simulations similar to actual trees were constructed using simple branching rules. Branch orientation with respect to the direction of gravity was a fundamental consideration. In Cornus kousa BUERG. ex HANCE, several types of branches develop from winter buds, varying from orthotropic shoots to plagiotropic ones. Based on actual observations and measurements of branching structures with a wide range of orientations, we made a flexible geometrical model consisting of five forking branches that varied in outgrowth depending on the direction of the shoot with respect to gravity. Repetition of the branching by computer generated a realistic tree pattern, which was close to the shape of a young C. kousa tree. Reproductive shoots seem to be under a branching rule that was a modification of vegetative branching, although the reproductive branch size was considerably smaller than the vegetative one, and reproductive branching was bifurcated instead of five-forked. We conclude that all branchings in orthotropic and plagiotropic shoots in the vegetative phase and shoots in the reproductive phase are formed under the same branching rule, but each has different parameter values. 相似文献
16.
Renee J. Grayer-Barkmeijer 《Biochemical Systematics and Ecology》1978,6(2):131-137
Flavone glycosides are the main flavonoid leaf constituents in the related genera Parahebe and Veronica (Scrophulariaceae), in agreement with former chemical studies of the family. In Parahebe there are groups of species in which there are mainly luteolin glycosides, and groups in which 6-hydroxyluteolin dominates. Small amounts of apigenin occur in many taxa. Glycosylation is usually in the 7-position but 4′- and 5-glycosides were also found. In Veronica a larger variety of flavone aglycones was found: e.g. luteolin, apigenin, chrysoeriol, tricin and three different 6-hydroxyflavones. They are often present in the plants in the form of glucuronides. Glycosylation is in the 7-or-5-position. Most species of both genera have a distinctive pattern of flavonoid glycosides in their leaves which can be used for identification. Populations of P. catarractae are an exception in showing three different patterns, but here the variety in flavone profiles corresponds to the pattern of morphological and geographic variation within this taxon. Anthocyanins are responsible for the blue, mauve and pink colours of the flowers in the two genera. In Veronica they are based on delphinidin, whereas in Parahebe catarractae on both delphinidin and cyanidin. 相似文献
17.
A plant pathogen modulates the effects of secondary metabolites on the performance and immune function of an insect herbivore
下载免费PDF全文
![点击此处可从《Oikos》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Host plant chemical composition critically shapes the performance of insect herbivores feeding on them. Some insects have become specialized on plant secondary metabolites, and even use them to their own advantage such as defense against predators. However, infection by plant pathogens can seriously alter the interaction between herbivores and their host plants. We tested whether the effects of the plant secondary metabolites, iridoid glycosides (IGs), on the performance and immune response of an insect herbivore are modulated by a plant pathogen. We used the IG‐specialized Glanville fritillary butterfly Melitaea cinxia, its host plant Plantago lanceolata, and the naturally occurring plant pathogen, powdery mildew Podosphaera plantaginis, as model system. Pre‐diapause larvae were fed on P. lanceolata host plants selected to contain either high or low IGs, in the presence or absence of powdery mildew. Larval performance was measured by growth rate, survival until diapause, and by investment in immunity. We assessed immunity after a bacterial challenge in terms of phenoloxidase (PO) activity and the expression of seven pre‐selected insect immune genes (qPCR). We found that the beneficial effects of constitutive leaf IGs, that improved larval growth, were significantly reduced by mildew infection. Moreover, mildew presence downregulated one component of larval immune response (PO activity), suggesting a physiological cost of investment in immunity under suboptimal conditions. Yet, feeding on mildew‐infected leaves caused an upregulation of two immune genes, lysozyme and prophenoloxidase. Our findings indicate that a plant pathogen can significantly modulate the effects of secondary metabolites on the growth of an insect herbivore. Furthermore, we show that a plant pathogen can induce contrasting effects on insect immune function. We suspect that the activation of the immune system toward a plant pathogen infection may be maladaptive, but the actual infectivity on the larvae should be tested. 相似文献
18.
马蹄参属种子油脂肪酸的特征及其分类学意义 总被引:3,自引:0,他引:3
用气相色谱质谱方法分析了马蹄参(DiplopanaxstachyanthusHand.Mazz.)和近缘属植物挤果树参(DendropanaxconfertusLi)、桃叶珊瑚(AucubajaponicaThunb.)、毛(CornuswalteriWanger.)、八角金盘〔Fatsiajaponica(Thunb.)Dence.etPlanch.〕的种子油脂肪酸成分。结果表明在所测定的马蹄参种子油样本中含量最高的成分是亚油酸C18∶2(9C,12C),同时含有岩芹酸C18∶1(6C)这一异常脂肪酸。种子油脂肪酸分布特征支持将马蹄参属移出五加科,改隶于广义的山茱萸科。 相似文献
19.
A survey of 125 species of the Palmae revealed a complex pattern of flavonoids in the leaf. C-Glycosylflavones, leucoanthocyanins and tricin, luteolin and quercetin glycosides were common, being present in 84, 66, 51, 30 and 24% of the species respectively. Apigenin and kaempferol were recorded in only a few species and isorhamnetin only once. Eighteen flavonoids were identified: the 7-glucoside, 7-diglucoside and 7-rutinoside of both luteolin and tricin, tricin 5-glucoside, apigenin 7-rutinoside, quercetin 3-rutinoside-7-galactoside, isorhamnetin 7-rutinoside, orientin, iso-orientin, vitexin, isovitexin and vitexin 7-O-glucoside. Many of the C- and O-flavonoid glycosides were present as the potassium bisulphate salts and negatively charged compounds were detected in 50% of the species. The distribution patterns are correlated with the taxonomy of the family in several ways. Thus, the Phoenicoideae and Caryotoideae have distinctive flavonoid patterns, there is evidence to support the separation of the subfamilies Phytelephantoideae and Nypoideae, and tricin is a useful marker at tribal level. At the generic level, Cocos is clearly separated from Butia, and other Cocoseae and Mascarena and Chamaedorea form well defined groups within the Arecoideae. A numerical analysis of these biochemical data, together with morphological characters, produces a new classification which suggests that the flavonoid data may have more systematic value than is indicated when they are applied to the traditional classification. 相似文献
20.
The flavonoid composition of Saxifraga cernua, S. micranthidifolia, S. tolmiei, and S. tricuspidata has been determined. The major proportion of the profiles comprise a complex mixture of flavonol 3-O-glycosides, including mono-, di-, and triglycosides. Kaempferol, quercetin, isorhamnetin, and myricetin were observed although not all taxa had all aglycones. The monoglycoside fraction of S. tolmiei was unusual in that it consisted only of quercetin 3′-O-glucoside and myricetin 7-O-glucoside; both compounds are unusual for the family. Saxifraga tricuspidata exhibited an unusually complex array of monoglycosides which was comprised of glucosides, galactosides, xylosides, several isomeric arabinosides, and acylated derivatives of some of the arabinosides. The diversity of biosynthetic capacity observed for Saxifraga (present and earlier data) reflect the complexity described for the Saxifrageae. 相似文献