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71.
Nickel localization on tissues of hyperaccumulator species of Phyllanthus L. (euphorbiaceae) from Ultramafic Areas of Cuba 总被引:1,自引:0,他引:1
Berazaín R de la Fuente V Sánchez-Mata D Rufo L Rodríguez N Amils R 《Biological trace element research》2007,115(1):67-86
Two species of perennial Phyllanthus (Euphorbiaceae) (Phyllanthus orbicularis and Phyllanthus discolor, both endemic to ultramafic areas of Cuba, and their natural hybrid, Phyllanthus xpallidus) were selected for metal localization microanalysis. Different plant tissues were analyzed by X-ray fluorescence, inductively
coupled plasma—atomic emission spectroscopy, and scanning electron microscopy coupled with an energy-dispersive X-ray probe.
All of the studied taxa are nickel (Ni) hyperaccumulators and significant concentrations of this element were found in different
leaf and stem tissues. The highest Ni content was found in the laticifer tubes, whereas leaf epidermis Ni content resulted
to be much more relevant in terms of total metal storage. Calcium and magnesium were found more evenly distributed in leaf
and stem tissues. 相似文献
72.
Molecular investigation of the distribution, abundance and diversity of the genus Pseudoalteromonas in marine samples 总被引:3,自引:0,他引:3
The genus Pseudoalteromonas has attracted interest because it has frequently been found in association with eukaryotic hosts, and because many Pseudoalteromonas species produce biologically active compounds. One distinct group of Pseudoalteromonas species is the antifouling subgroup containing Pseudoalteromonas tunicata and Ps. ulvae, which both produce extracellular compounds that inhibit growth and colonization by different marine organisms. PCR primers targeting the 16S rRNA gene of the genus Pseudoalteromonas and the antifouling subgroup were developed and applied in this study. Real-time quantitative PCR (qPCR) was applied to determine the relative bacterial abundance of the genus and the antifouling subgroup, and denaturing gradient gel electrophoresis (DGGE) was applied to study the diversity of the genus in 11 different types of marine samples from Danish coastal waters. The detection of Ps. tunicata that contain the antifouling subgroup was achieved through specific PCR amplification of the antibacterial protein gene (alpP). The Pseudoalteromonas species accounted for 1.6% of the total bacterial abundance across all samples. The Pseudoalteromonas diversity on the three unfouled marine organisms Ciona intestinalis, Ulva lactuca and Ulvaria fusca was found to be low, and Ps. tunicata was only detected on these three hosts, which all contain accessible cellulose polymers in their cell walls. 相似文献
73.
A new genus of Cobitinae, Bibarba gen. n., and a new species, B. bibarba sp. n., were discovered and are described for the Chengjiang River, a tributary of the Hongshuihe River in Guangxi Province of southern China. This river region is characterized by a Karst landscape, and the river that is inhabited by the new genus is a slowly moving stream with arenaceous and cobblestone beds. The new genus resembles Cobitis Linnaeus, 1758 (subfamily Cobitinae) in the shape and pigmentation pattern of their body, the absence of scales on their head, and the presence of a suborbital spine, but differs from it by a single Lamina circularis on the third pectoral fin ray instead of on the base of the second pectoral fin ray; two pairs of barbels (one rostral pair and one maxillo-mandibular pair) instead of three pairs of barbels (one rostral pair, one maxillary pair, and one maxillo-mandibular pair); a relatively thick and short suborbital spine with a strong medio-lateral process instead of a suborbital spine without or with a weakly formed medio-lateral process as in Cobitis; and the lack of a black stripe extending from the occiput through the eye to the insertion of the rostral barbel. The first two characters have not been reported in any other genus of the subfamily Cobitinae. A morphometric character analysis based on PCA reveals differences between B. bibarba and C. sinensis in body size, barbel length, interorbital width, pectoral fin length in males, and the position of the dorsal and ventral fins. Type specimens of the new species are kept in the Freshwater Fishes Museum of the Institute of Hydrobiology at the Chinese Academy of Sciences in Wuhan, Hubei Province. 相似文献
74.
记述了云南曲靖地区早泥盆世洛霍考夫期华南鱼类一新属———王冠鱼(Stephaspis gen.nov.)。新属发现于西山村组下部致密坚硬的石英砂岩中,其主要特征是:个体较大的华南鱼类,头甲呈长盾形,后缘向后凸出;角发育,侧向延伸,末端向头甲后侧方自然倾斜,内角不发育;具吻突,但不甚发育;中背孔较大,呈纵向椭圆形,前端稍尖,后端圆钝;眶孔较小,圆形,背位;头甲背面具一对背窗,呈狭长椭圆形,靠近头甲侧缘;感觉管系统不甚发育,仅见后眶上管、侧背管、侧横管及背联络管,后眶上管呈V字形;纹饰为细小的粒状瘤点。新属不仅是华南鱼类在西山村组的首次发现,也指示了目前华南鱼类出现的最低层位,为探讨华南鱼类的起源与早期辐射提供了重要资料。 相似文献
75.
76.
77.
记述中国皿蛛科1新纪录属和1新种:莫蛛属Moebelia Dahl,1886,方胫莫蛛 Moebelia rectangula sp.nov.模式标本保存于中国科学院动物研究所,北京.
方胫莫蛛,新种Moebelia rectangula sp.nov.(图1~11)
正模♂,河北嶂石岩, 2005-09-12 ,李枢强采;副模8♀♀,12 ♂♂,河北嶂石岩,李枢强等采; 4♀♀,7♂♂,北京门头沟,王倩等采。
新种与产自芬兰的毛笔莫蛛Moebelia penicillata(图12~22)相近,两者主要区别:前者触肢胫节无毛笔状毛簇;前者触肢前侧胫节突方形,后者锥形;前者超盾片突无三角形片状突起;前者外雌器后缘比后者宽;前者纳精囊之间的距离窄于后者。 相似文献
78.
在整理河北大学博物馆馆藏的蝗总科标本中,发现1新属4新种,它们为斑腿蝗科Catantopidae的广西龙川蝗Longchuanacris guangxiensis sp.nov.,斑翅蝗科Oedipodidae的拟短腿蝗属Parahilethera gen.nov.,西藏拟短腿蝗Parahilethera xizangensis sp.nov.及淡黑纹束颈蝗Sphingonotus caerulistriatus sp.nov.,网翅蝗科Arcypteridae的拟中宽雏蝗Chorthippus parapricarius sp.nov..模式标本保存于河北大学博物馆. 相似文献
79.
80.
Trias, an orchid genus, was reported in this paper from China as a newly recorded genus for the first time. The genus and its new species, T. verrucosa Z. J. Liu, L. J. Chen et S. P. Lei, were described and discussed. Trias consists of 19 species ranging from Assam of India to Indonesia and Australia in the southeast via Myanmar to Deccan of India in the southwest. Its occurrence in West Yunnan of China is a further indication of phytogeographical relations between this region and the tropical Asia. This new species grows on shady rocks in forests. By observing of its biological characteristics such as phenology and blooming biology, lots of cloned ramets of generation overlap were found, but there were no fruited plants, and that clonal reproduction could repeat had nothing to do with whether the ramet bloomed or not. The flowering season of this species is from early April to early May. The opening of flowers on plants or inflorescence was irregular and the florescence of single flowers was rather short, only lasting 4–5 d, and no fruited flowers were found. Based on the detection of mating systems, no flowers of artificial self-pollination and artificial cross-pollination have fruited. Since the flowering period is just before the rainy season in this region, the ecological conditions of dryness, strong wind, low temperature and weak light during that period of time are evidently unfavorable to plant blooming, pollinating and fruiting. Apparently, the short duration and sterility of each flower would avoid the invalid energy waste in unfavorable circumstances and save the limited energy for more valid asexual reproduction so that the opportunity of multiplication in an uncertain environment would be increased to ensure the progenitive success. The P/O value of T. verrucosa is 187.4 ± 22.4, which is obviously related with the highly valid usage of its conglutinated and hard tuberous pollinarium during pollination, indicating that this species could hold the characteristic of sexual reproduction. This is an adaptation of this type of plants to the rather atrocious ecological circumstance there by its reproduction strategy of strengthening asexual reproduction and weakening sexual reproduction, and so it enables the plants to survive in this region, long-distanced from the places where its relatives dwell. 相似文献