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 140 毫秒
1.
缺瓣牛姆瓜Holboellia apetala Q.Xia,J.Z.Suen et Z.X.Peng在一系列特征上与牛姆瓜属Holboellia植物不同,不应隶属于该属,而代表了一个未被描述过的新属—长萼木通属。新属在茎、叶、果实和花的大部分特征上与木通属Akebia相似,但花萼特征又与野木瓜属Stauntonia接近,其系统位置介于这两个属之间,并偏于前者。  相似文献   

2.
锦鸡儿属植物区系成份分析   总被引:17,自引:2,他引:15  
杨昌友  李楠 《植物研究》1990,10(4):93-99
锦鸡儿属(Caragana Fabr.)属蝶形花科山羊豆族,是温带亚洲的代表属之一。本文对锦鸡儿属已知种类的区系成份进行了研究,将105种植物共划分为20个分布区类型,其中包括:(1)青藏高原分布;(2)沿喜马拉雅分布;(3)云贵高原分布;(4)云贵高原—华北分布;(5)秦岭山地分布;(6)华北分布;(7)中国东北分布;(8)蒙古高原分布;(9)西伯利亚阿尔泰分布;(10)亚洲中部分布;(11)西亚分布;(12)天山山地分布;(13)帕米尔—阿赖依分布;(14)小亚细亚—里海—哈萨克斯坦分布;(15)准噶尔—哈萨克斯坦分布;16)塔尔巴哈台—准噶尔—蒙古分布;(17)准噶尔特有分布;(18)昆仑山特有分布;(19)黑海—西西伯利亚分布;(20)欧洲—高加索分布。统计结果表明:属青藏高原分布的种类最为丰富,有18种,占总数的17.16%,沿喜马拉雅分布次之,共计12种,占总数的11.45%;再次之是中国华北分布和天山山地分布,均为10种,占总数的9.54%。通过区系分析可以清晰地看出:本属在中国,的分布很广,种类也很多,共计80种,约占全属总数的76.32%。中国特有种也很丰富,共计43种,占全国分布总数的一半以上(53.75%),占本属总数的40.95%。  相似文献   

3.
报道了海南兰科植物1个新记录属—金唇兰属(基于金唇兰,并提供简要的描述、照片及属的分布图。  相似文献   

4.
陈汉彬 《四川动物》1989,8(2):28-29
在整理云南蚊类标本过程中,发观库蚊属(Culex)4种新纪录,分别隶属于库状蚊亚属(Culiciomyia)1种、簇角蚊亚属(Lophoceraomyia)2种和库蚊亚属(Culex)1种。一、佛氏库蚊Culex(Cui.)fragilis Ludlow,1903检视标本:云南,勐腊。1985,Ⅷ,10—4,14,4L,采自木槽积水。鉴别特征:腹节背板全暗。雄蚊抱肢端节齿脊自亚端部伸达亚基部。幼虫头毛5,6—C从亚基部各分出5—7芒支。前胸毛1—3P均不分支。呼吸管较短,自基部向端部渐变细。呼吸管毛1—S3对,每分2—3支。本种幼虫特征突出,不难与我国已知的库状蚊相区别。本种在国外分布于泰国、菲律宾、印…  相似文献   

5.
俞藤属—葡萄科一新属   总被引:2,自引:0,他引:2  
作者在研究中国葡萄科植物过程中发现分布于中国亚热带、尼泊尔和印度卡西山区一些植物种自成一类,与葡萄科现有属的定义不符,命名为一新属-愈藤属(YuaC.L.Li)。文中讨论了它与爬山虎属(Parthenocissus Planch.)、崖爬藤属(TetrastigmaPlanch.)、乌蔹莓属(CayratiaJuss.)和蛇葡萄属(Ampelopsis Michx.)的区别,并在野外和栽培条件下观察了某些重要属级鉴定性状在个体发育过程中的表现,以证明其可靠。为了正确鉴定这个属和种类,给出了包括这些属在内的国产葡萄科植物分属检索表和该属的分种检索表,最后,讨论了俞藤属的地理分布及其意义。  相似文献   

6.
山白树属及其近缘属聚类分析   总被引:1,自引:0,他引:1  
运用系统聚类分析法,对山白树属及其近缘属进行定量分析,结果表明山白树属与牛鼻栓属亲缘关系密切,可组成一族,该族与蚊母树族有着较近的亲缘。  相似文献   

7.
陈斌  周尧 《昆虫分类学报》1996,18(4):265-269
本文记述了采自于四川西部的角伪叶甲属CerogriaBorchmann1909一新亚属及二新种。模式标本保存于西北农业大学昆虫研究所。畸角伪叶甲亚属Aeschrocera,新亚属该亚属的触角(图2~5)基节强烈地呈球状膨大,除第7和9节强烈呈锯齿状膨大外,第4~6节也明显呈锯齿状膨大,第8和10节中部呈尖锐的角状突出,端节也向一侧扩宽;阳基侧突强烈地叶状扩宽。这些特征易与其它亚属区别。模式种;褐胸畸角伪叶甲Cerogria(Aeschrocera)brunneocolis,sp.nov.1.褐胸畸角伪叶甲Cerogria(Aeschrocera)brunneocolis,新种(图1~5)该种触角端节腹面常形,端节直;前胸背板褐色;额侧突基瘤间的分界沟不清楚。正模,西康日地,1939—Ⅸ—1。副模1,1♀,同正模;3,3♀♀,西康康定,1939—Ⅷ—9(3),1939—Ⅷ—18(1♀),1939—Ⅷ—28(1♀),1931—Ⅷ—28(1♀);1,西康丹巴,1939—Ⅹ—3;1,西康榆林宫,1939—Ⅸ—7;1,西康瓦斯井,1939—Ⅸ—2;1♀,西康旋牛,1939—Ⅹ—6,周尧采。2.钩畸角  相似文献   

8.
综述了番茄属和茄属的属间细胞杂交研究进展,并对植物细胞杂交研究的发展和存在问题进行了讨论。  相似文献   

9.
根据形态学特征及线粒体Cyt b和COⅠ基因对我国泥鳅属(Misgurnus)和副泥鳅属(Paramisgurnus)鱼类进行了分类整理。结果表明: 泥鳅属和副泥鳅属鱼类在鳞焦大小, 须长及基枕骨末端愈合程度等特征上存在差异。基于联合基因分析, 泥鳅属和副泥鳅属属间遗传距离(15.2%—17.5%)接近于泥鳅属种间遗传距离(10.7%—18.4%); 分子系统树显示我国泥鳅属鱼类未构成单系, 副泥鳅属嵌套分布于泥鳅属中; 北方泥鳅(Misgurnus bipartitus)和泥鳅(Misgurnus anguillicaudatus)亲缘关系近, 其次是大鳞副泥鳅(Paramisgurnus dabryanus), 黑龙江泥鳅(Misgurnus mohoity)位于系统树的基部。结合形态特征与分子数据, 副泥鳅属应作为泥鳅属同属异名, 大鳞副泥鳅应归入泥鳅属; 北方泥鳅曾为黑龙江泥鳅的同物异名, 与黑龙江泥鳅存在明显的形态差异, 且两者亲缘关系较泥鳅远, 北方泥鳅为有效种。  相似文献   

10.
作者在前两篇文章里报道了湖北省神农架产的尾孢菌属及其近似属的22个种,本文再报道这一地区的尾孢菌属、短胖孢属及色链隔孢属的4个种,其中1个是新种,即李色链隔孢(Phaeoramularia pruni Guo et Liu,sp.nov.),其模式标本收藏于中国科学院真菌标本室(HMAS)。该新种与寄生于李属(Prunus sp.)植物上的变红尾孢(Cercospora rubrotincta)接近,但后者分生孢子梗窄(2—4.5μm),不分枝,曲膝状折点少(0—1个),分生孢子向顶渐狭,不链生,隔膜多(1—5隔),因此易于区别。  相似文献   

11.
Aquaporins: water channel proteins of the cell membrane   总被引:37,自引:0,他引:37  
Aquaporins (AQP) are integral membrane proteins that serve as channels in the transfer of water, and in some cases, small solutes across the membrane. They are conserved in bacteria, plants, and animals. Structural analyses of the molecules have revealed the presence of a pore in the center of each aquaporin molecule. In mammalian cells, more than 10 isoforms (AQP0-AQP10) have been identified so far. They are differentially expressed in many types of cells and tissues in the body. AQP0 is abundant in the lens. AQP1 is found in the blood vessels, kidney proximal tubules, eye, and ear. AQP2 is expressed in the kidney collecting ducts, where it shuttles between the intracellular storage sites and the plasma membrane under the control of antidiuretic hormone (ADH). Mutations of AQP2 result in diabetes insipidus. AQP3 is present in the kidney collecting ducts, epidermis, urinary, respiratory, and digestive tracts. AQP3 in organs other than the kidney may be involved in the supply of water to them. AQP4 is present in the brain astrocytes, eye, ear, skeletal muscle, stomach parietal cells, and kidney collecting ducts. AQP5 is in the secretory cells such as salivary, lacrimal, and sweat glands. AQP5 is also expressed in the ear and eye. AQP6 is localized intracellular vesicles in the kidney collecting duct cells. AQP7 is expressed in the adipocytes, testis, and kidney. AQP8 is expressed in the kidney, testis, and liver. AQP9 is present in the liver and leukocytes. AQP10 is expressed in the intestine. The diverse and characteristic distribution of aquaporins in the body suggests their important and specific roles in each organ.  相似文献   

12.
It is noteworthy that in the rat the early postnatal life is marked by an activation of both the corticostimulating function of the adenohypophysis in neonates of both sexes and of the gonadostimulating function mainly in males. In order to specify if such neuroendocrine variations are temporally correlated with changes in the hypothalamic metabolism of neurotransmitters, the hypothalamic metabolism of serotonin (5 HT), norepinephrine (NE), and dopamine (DA) and the hypothalamic content of neuropeptide Y (NPY) have been investigated in newborn rats of both sexes, delivered at term by cesarean section, as well as changes in the activity of both the hypothalamo-pituitary adrenal axis (HPA) and the hypothalamo-pituitary gonadal axis (HPG). Experimental data suggested that 1) in males a rise in hypothalamic metabolism of 5 HT, NE and DA occurs during the first two hours after delivery, whereas in females, only the metabolism of NE increases. Moreover, the postnatal metabolism of NE was higher in females than in littermate males; 2) NPY content of the hypothalamus, which was at birth significantly higher in males than in females, dropped in the former but not in the latter; 3) in newborn males, an early surge of plasma testosterone occurs, suggesting postnatal activation of the HPG axis; on the other hand, in females, a late and slight increase in plasma estradiol is observed; 4) in early postnatal life, a sex-independent rise in plasma ACTH and adrenal and plasma corticosterone levels suggest a comparable activation of the HPA axis in newborns of both sexes. In conclusion, the early postnatal activation of the corticostimulating function in neonates of both sexes and that of the gonadostimulating function, mainly in males, could be temporally correlated with a rise in the hypothalamic metabolism of two neurotransmitters, 5 HT and NE, and of NPY content. According to our data, a sex-dependent metabolsim of neurotransmitters in the hypothalamus is already apparent in early postnatal life.  相似文献   

13.
Arginase, ornithine carbamoyl transferase (OCT) and arginine deiminase activities were found in cell-free extracts of Nostoc PCC 73102, a free-living cyanobacterium originally isolated from the cycad Macrozamia. Addition of either arginine, ornithine or citrulline to the growth medium induced significant changes in their in vitro activities. Moreover, growth in darkness, compared to in light, induced higher in vitro activities. The in vitro activities of arginase and arginine deiminase, two catabolic enzymes primarily involved in the breakdown of arginine, increased substantially by a combination of growth in darkness and addition of either arginine, or ornithine, to the growth medium. The most significant effects on the in vitro OCT activities where observed in cells grown with the addition of ornithine. Cells grown in darkness exhibited about 6% of the in vivo nitrogenase activity observed in cells grown in light. However, addition of external carbon (glucose and fructose) to cells grown in darkness resulted in in vivo nitrogenase activity levels similar to, or even higher than, cells grown in light. Growth with high in vivo nitrogenase activity or in darkness with the addition of external carbon, resulted in repressed levels of in vitro arginase and arginine deiminase activities. It is suggested that nitrogen starvation induces a mobilization of the stored nitrogen, internal release of the amino compound arginine, and an induction of two catabolic enzymes arginase and arginine deiminase. A similar and even more pronunced induction can be observed by addition of external arginine to the growth medium.  相似文献   

14.
Significant seasonal differences in intra- and interorgan prevalence, abundance and distribution of rodlet cells (RC) were observed in freshwater bream caught in May and August 1997 from a PCB-polluted lake, Lake Kernaala, Finland. In May, the majority of RCs in liver were seen in blood vessel endothelium, while in August most cells were located in the epithelium of the intrahepatic biliary ducts. In kidney, a significant increase in RCs in the columnar epithelium of the collecting ducts was observed from May to August. RCs in spleen were extremely rare in May, but were seen frequently in the endothelium of the splenic blood vessels in August. In gill and intestine, RCs were found in every tissue sample studied, with no statistical differences in their abundance or distribution between seasons. No RCs were seen in gonads. Total numbers of RCs increased dramatically from May to August in kidney and in spleen. The frequency of RCs corresponded strongly with the current phase of parasitic infections in liver, kidney, and spleen. It is concluded that RCs play a role in host defence mechanisms in fish, displaying induced expression at the times of peak parasitic prevalences.  相似文献   

15.
Recent coral spawning observations in the central Red Sea show that most scleractinian species release their gametes in the spring, with a majority of species spawning in April. There is, however, a lack of reproductive data for several other coral species, as well as a general lack of data for other invertebrates. Here, we document the detailed timing of spawning for 13 scleractinian coral species, one sea anemone, and six echinoderms from an inshore reef off the coast of Thuwal, Saudi Arabia, in the spring between April and June 2014. Furthermore, inferred from the presence of mature gametes, we report the month of spawning for three additional coral species in the spring. Seven scleractinian coral species were inferred to release their gametes in a second reproductive season, in the autumn, between September and November. This is the first report of a second spawning season in the Arabian region. Biannual spawning has so far been reported on the Great Barrier Reef, in Western Australia, in Indonesia, in Malaysia, in Palau, in Thailand, in Taiwan, and in Western Samoa.  相似文献   

16.
S. Xie  Y. Cui    T. Zhang  Z. Li 《Journal of fish biology》2000,57(4):867-880
Feeding ecology of three small fish species, Hypseleotris swinhonis, Ctenogobius giurinus and Pseudorasbora parva was studied seasonally in the Biandantang Lake, a small, shallow lake in central China. Gut length, adjusted for total body length, was significantly higher in spring than in other seasons for all the three species. Seasonal changes in gut length were not associated with changes in food quality. Weight of fore-gut contents, adjusted for body weight, was significantly higher in winter and spring than in summer and autumn in H. swinhonis and C. giurinus , and significantly higher in autumn than in spring and summer for P. parva. Percentage of empty fore-guts was highest in summer and lowest in spring for H. swinhonis and C. giurinus , and highest in winter and lowest in autumn for P. parva. Diet of the three small fishes showed apparent seasonal changes, and these changes reflected partly the seasonal fluctuations of food resources in environment. Diet breadth was high in winter and low in autumn for H. swinhonis , high in winter and low in spring and summer for C. giurinus , and high in autumn and low in spring for P. parva. Diet overlaps between pairs of species were biologically significant in most cases, except between H. swinhonis and P. parva in summer and autumn and between C. giurinus and P. parva in autumn.  相似文献   

17.
Growth rate, mineral composition and changes in polyamine concentration induced in response to salinity were studied in six crop species: spinach, lettuce, bean, pepper, beetroot and tomato. Salinity decreased growth rate, but sensitivity differed amongst the species: pepper being the most sensitive, followed by bean, tomato, lettuce and spinach, with beetroot being the most tolerant. The increase of Na+ and total cation with salinity in shoots was the highest in spinach and beetroot, the most tolerant species, while in pepper it was the lowest. Changes in putrescine (Put) concentration in shoots were related to salinity tolerance (increased in the most sensitive), while changes in spermidine (Spd; decreases) and spermine (Spm; increases) were similar with most species, except for pepper in which salinity strongly increased Put, Spd and Spm. Therefore, total polyamine concentration increased in pepper shoot, while it decreased in the other species. Thus, results show that Put accumulation was a consequence of salt stress in the most sensitive species, while salt tolerant species (beetroot) showed little change in polyamine concentration, and higher concentration in both Na+ and total cations. The role of polyamines or cation increased concentration after saline treatment in species with different salt tolerance is discussed.  相似文献   

18.
The neuropeptide oxytocin has been implicated in the regulation of affiliative behavior and maternal responsiveness in several mammalian species. Rodent species vary considerably in the expression of juvenile alloparental behavior. For example, alloparental behavior is spontaneous in juvenile female prairie voles (approximately 20 days of age), takes 1-3 days of pup exposure to develop in juvenile rats, and is nearly absent in juvenile mice and meadow voles. Here, we tested the hypothesis that species differences in pup responsiveness in juvenile rodents are associated with oxytocin receptor (OTR) density in specific brain regions. We found that OTR density in the nucleus accumbens (NA) is highest in juvenile prairie voles, intermediate in juvenile rats, and lowest in juvenile mice and meadow voles. In the caudate putamen (CP), OTR binding was highest in prairie voles, intermediate in rats and meadow voles, and lowest in mice. In contrast, the lateral septum (LS) shows an opposite pattern, with OTR binding being high in mice and meadow voles and low in prairie voles and rats. Thus, alloparental responsiveness in juvenile rodents is positively correlated with OTR density in the NA and CP and negatively correlated with OTR density in the LS. We then investigated whether a similar receptor-behavior relationship exists among juvenile female prairie voles by correlating individual variation in alloparental behavior with variation in OTR density. The time spent adopting crouching postures, the most distinctive component of alloparental behavior in juveniles, was positively correlated with OTR density in the NA (r = 0.47) and CP (r = 0.45) and negatively correlated with OTR density in the lateral septum (r = -0.53). Thus, variation in OTR density in the NA, CP, and LS may underlie both species and individual differences in alloparental care in rodents.  相似文献   

19.
太原西山煤田太原组煤核中的科达植物雌性生殖器官   总被引:1,自引:0,他引:1  
报道了首次发现于我国的3种石化科达植物雌性生殖器官Cordaianthus sp.nov.,C.xishanensis sp.nov.和C.sp.,描述了它们的内部解剖构造特征,并与欧美植物区的雌性石化科达穗进行了比较,这些化石产于山西太原西山煤田太原组组上部7号煤层煤核中。  相似文献   

20.
We present an updated worldwide phylogenetic classification of Poaceae with 11 783 species in 12 subfamilies, 7 supertribes, 54 tribes, 5 super subtribes, 109 subtribes, and 789 accepted genera. The subfamilies (in descending order based on the number of species) are Pooideae with 4126 species in 219 genera, 15 tribes, and 34 subtribes; Panicoideae with 3325 species in 242 genera, 14 tribes, and 24 subtribes; Bambusoideae with 1698 species in 136 genera, 3 tribes, and 19 subtribes; Chloridoideae with 1603 species in 121 genera, 5 tribes, and 30 subtribes; Aristidoideae with 367 species in three generaand one tribe; Danthonioideae with 292 species in 19 generaand 1 tribe; Micrairoideae with 192 species in nine generaand three tribes; Oryzoideae with 117 species in 19 genera, 4 tribes, and 2 subtribes; Arundinoideae with 36 species in 14 genera and 3 tribes; Pharoideae with 12 species in three generaand one tribe; Puelioideae with 11 species in two generaand two tribes; and the Anomochlooideae with four species in two generaand two tribes. Two new tribes and 22 new or resurrected subtribes are recognized. Forty-five new (28) and resurrected (17) genera are accepted, and 24 previously accepted genera are placed in synonymy. We also provide an updated list of all accepted genera including common synonyms, genus authors, number of species in each accepted genus, and subfamily affiliation. We propose Locajonoa, a new name and rank with a new combination, L. coerulescens. The following seven new combinations are made in Lorenzochloa: L. bomanii, L. henrardiana, L. mucronata, L. obtusa, L. orurensis, L. rigidiseta, and L. venusta.  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