首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Abstract

The relative concentration and distribution of nickel (Ni) in vegetative tissues (leaves, stems and trichomes) and reproductive organs (seeds) was studied using energy-dispersive X-ray microanalysis (EDXS) and scanning electron microscopy (SEM) in two previously studied Ni-hyperaccumulator subspecies of Alyssum serpyllifolium Desf. growing naturally in ultramafic soils of the Iberian Peninsula: A. serpyllifolium ssp. lusitanicum Dudley & P. Silva and A. serpyllifolium ssp. malacitanum Rivas Goday ex G. López. Both taxa showed that Ni accumulates preferentially in the leaves, exhibiting a homogeneous distribution on both epidermis surfaces. The highest Ni concentrations were found inside the epidermal cells and at the base of trichome stalks. Ni accumulation in seeds was lower than in the vegetative organs. The location of Ni in these plants allows us to postulate that its accumulation is a protection mechanism against external stress.  相似文献   

2.
王文采 《广西植物》2019,39(3):285-287
该文描述了自西藏南部发现的毛茛科毛茛属一新种,康马毛茛(Ranunculus kangmaensis)。此新种与特产云南的梅里山毛茛(R. meilixuoshanicus KadotaMing)近缘,两者的区别是康马毛茛的花葶较高,叶较大,3深裂,花具8枚且较大,并具较长爪的花瓣。  相似文献   

3.
4.
5.
Trigonotis jiaochengensis Q. R. Liu & R. Y. Yan, a new species from Shanxi, China, is described and illustrated here. It is similar to T. peduncularis in having multiple diffuse stems, ovate to elliptic leaf blades, scorpioid cyme with only basal bracts and trigonous‐tetrahedral nutlets, but differs in having slender pedicels that are 5.2–18.4 mm long (vs clavate pedicels 1.5–4.8 mm in T. peduncularis), smooth nutlets with a short carpophore and a flat bottom (vs verrucose nutlets with a long carpophore and convex bottom in T. peduncularis). Morphological characters, including pollen and nutlets, with illustrations, diagnostic comparisons and habitat, are presented.  相似文献   

6.
A new yeast species,Torulopsis bombicola, is described, that produces extracellular hydroxy fatty acid sophorosides. It utilizes relatively few carbon compounds. It forms a mannan having a proton magnetic resonance spectrum similar to the spectra of the galactomannans ofTorulopsis apis, Torulopsis nodaensis andT. magnoliae, but differing from those ofT. gropengiesseri galactomannan andT. apicola mannan.Issued as N.R.C.C. No. 11234.The authors wish to thank Mr. M. Mazurek for the determination of the p.m.r. spectra, and Mr. N. R. Gardner and Mr. R. J. Magus for valuable technical assistance.  相似文献   

7.
A new species, Eleocharis khandwaensis Mujaffar, Chandore & S. R. Yadav is described from the Bamangaon village of Khandwa district in Madhya Pradesh state, India. This species belongs to Eleocharis subgen. Limnochloa (P. Beauv. ex Lestib.) Torr. and it is similar to E. lankana T. Koyama but differs in having stolons, weak bristles spinules of perianth, achenes with annulate apex with a short neck, truncate achene base, dark brown to black coloured achenes and nut surface epidermal cells that are isodiametrically hexagonal to pentagonal. Eleocharis khandwaensis grows in ponds along road sides in the Bamangaon and Tirandaz villages.  相似文献   

8.
Nickel uptake and cellular compartmentation were investigated in three Ni hyperaccumulators: Alyssum bertolonii (Desv), Alyssum lesbiacum (Candargy) and Thlaspi goesingense (Hálácsy). The three species showed similar hyperaccumulation of Ni, but T. goesingense was less tolerant to Ni than the two Alyssum species. An addition of 500 mg Ni kg(-1) to a nutrient-rich growth medium significantly increased shoot biomass of all three species, suggesting that the Ni hyperaccumulators have a higher requirement for Ni than normal plants. Energy-dispersive X-ray microanalysis (EDXA) was performed on frozen-hydrated tissues of leaves (all species) and stems (Alyssum only). In all species analysed, Ni was distributed preferentially in the epidermal cells, most likely in the vacuoles, of the leaves and stems. In stems, there was a second peak of Ni in the boundary cells between the cortical parenchyma and the vascular cylinder. The non-glandular trichomes on the leaf surfaces of the two Alyssum species were highly enriched with Ca, but contained little Ni except in the base. In the leaves of T. goesingense, the large elongated epidermal cells contained more Ni than the cells of the stomatal complexes. The role of cellular compartmentation in Ni hyperaccumulation is discussed.  相似文献   

9.
10.
Abstract

Embryo suspensor in Cruciferae. I. Morphology and structure. — Embryo suspensors in seven species of Cruciferae (Alyssum argenteum All., Brassica nigra (L.) Koch, Capsella bursa-pastoris (L.) Medicus, Diplotaxis erucoides (L.) DC., Eruca sativa Miller, Lepidium graminifolium L., Matthiola tricuspidata (L.) R. Br.) were morphologically investigated. These species have significant differences in their seeds, so that probable differences could be found in the structure of their ovules and therefore of their suspensors. Results indicate that it is impossible to generalize on the suspensor morphology and structure even in the same family. In Eruca sativa and Brassica nigra polyploidy and polyteny were found, suggesting a probably important metabolic function of their suspensors. In the other species polyteny was not present; a various degree of polyploidy could probably be assumed, suggesting a less active function of suspensors, maybe absorption and transport of nutritive material from the integuments to the developing embryo. The development of the endosperm is almost the same in all species, so that seems to be improbable a negative correlation with the suspensor and endosperm function in the early embryogenesis.  相似文献   

11.
12.
A new species of Goniothalamus (Blume) Hook.f. & Thomson (Annonaceae), G. banii B. H. Quang, R. K. Choudhary & V.T. Chinh, is described and illustrated from Thanh Hoa Province, Vietnam. This species shows morphological similarities with G. uvarioides King and G. donnaiensis Finet & Gagnep. but is differentiated by having 22–30 (or more) secondary veins in the leaf, a 1–3‐flowered cyme, a ca 2–3 cm long pedicel, lanceolate and tomentose outer petals, stipitate obovoid‐oblong monocarps, and a single‐seeded monocarp.  相似文献   

13.
Two new species and one new variety of Elatostema J. R. Forst. & G. Forst. (Urticaceae) are described from Yunnan and Xizang, China. Habitat details and morphological comparison with similar species are given and discussed. The new taxa proposed are: Elatostema densistriolatum W. T. Wang & Zeng. Y. Wu, E. latistipulum W. T. Wang & Zeng Y. Wu and E. cyrtandrifolium (Zoll. & Mor.) Miq. var. hirsutum W. T. Wang & Zeng Y. Wu.  相似文献   

14.
A new species of Chiritopsis (Gesneriaceae), C. danxiaensis W. B. Liao, S. S. Lin & R. J. Shen, is described and illustrated from Mount Danxiashan, Guangdong Province, China. The new species is morphologically closely related to C. lobulata and C. cordifolia, but is characterized by having denticulate bracts, yellowish corolla, 2 glabrous staminodes and longer style. A revised key to all species of the genus is also provided.  相似文献   

15.
A secondarily formed reticulum of cells that encloses axial strands and a carposporophyte that is almost entirely converted to sporangia are the diagnostic features of a new genus, Reticulocaulis (Naccariaceae, Nemaliales), with R. mucosissimus as the type species. A new species of Naccaria, N. hawaiiana permits close comparison with the new genus and other previously described species of Naccaria. Until now, no Naccariaceae were known in the Pacific, and these new taxa are part of the sketchily known subtidal marine flora of Hawaii.  相似文献   

16.
Pleurospermum tripartitum Pu, R. Li & H. Li, a new species of Umbelliferae from western Yunnan, China, is described and illustrated. It is closely similar to P. macrochlaenum K. T. Fu & Y. C. Ho, but differs by having unbranched stem, conspicuous calyx teeth, and white petals.  相似文献   

17.
18.
A new species Dendrocalamus menglongensis Hsueh & K. L. Wang ex N. H. Xia, R. S. Lin &Y. B. Guo is described and illustrated from Xishuangbanna, Yunnan, China. It differs from D. giganteus by e.g. shorter internodes, 4–5 florets, a perfect terminal floret and persistent culm sheaths. A key to the new species and the other 7 species of Dendrocalamus known from Xishuangbanna is provided.  相似文献   

19.
Strain BBS, the purple sulfur bacterium assigned initially to the species Thiocapsa roseopersicina, is the best studied representative of this species. However, no molecular phylogenetic analysis has been performed to confirm its systematic position. Based on the results of analysis of the sequences of 16S rRNA, cbbL, and nifH genes, DNA-DNA hybridization with the T. roseopersicina type strain, and comparative analysis of the phenotypic characteristics of various species belonging to the genus Thiocapsa, we suggest that strain BBS should be assigned to a new species of the genus Thiocapsa, Thiocapsa bogorovii sp. nov. Original Russian Text ? T.P. Tourova, O.I. Keppen, O.L. Kovaleva, N.V. Slobodova, I.A. Berg, R.N. Ivanovsky, 2009, published in Mikrobiologiya, 2009, Vol. 78, No. 3, pp. 381–392.  相似文献   

20.
For many years the biosystematic status of several species in the Rhipicephalus sanguineus group has been confused, with the result that they have often been misidentified. Over the years some 18 of these species have been synonymised with R. sanguineus (Latreille, 1806) itself. More recently four new species in the group have been described: R. guilhoni Morel & Vassiliades, 1963; R. moucheti Morel, 1964; R. bergeoni Morel & Balis, 1976; and R. camicasi Morel, Mouchet & Rodhain, 1976.The literature on this group is critically reviewed and the main systematic problems analysed. R. sulcatus Neumann, 1908 and R. turanicus Pomerantsev, 1936 are two species that were confused both morphologically and ecologically. This has resulted in erroneous conclusions regarding their host relationships and distributions. Integrated biological, morphological and ecological studies on these two species have been conducted. Cross-breeding experiments have proved that both are distinct taxonomic entities. Interbreedings between African and Cypriot strains of R. turanicus demonstrated marked heterosis.A scanning electron microscope was used to determine the main diagnostic morphological differences between the larvae, nymphae and adults of R. sulcatus and R. turanicus, and the morphological similarities between African and Cypriot strains of R. turanicus. Rhipicephalus sulcatus occurs widely in the Afrotropical region in wetter ecological habitats and most frequently parasitises hares, dogs and jackals. R. turanicus occurs more-or-less throughout the Afrotropical region in a wide range of climatic biotopes, as well as in parts of southern Europe, Arabia and Asia, and is most abundant in the late rainy/early dry seasons. It occurs on a wide range of domesticated and wildlife hosts, including ground-feeding birds.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号