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1.
该文报道了采自中国浙江庆元县百山祖国家级自然保护区木兰科含笑属一新种——尾叶含笑(Michelia caudata M.X.Wu,X.H.Wu & G.Y.Li),该种与野含笑(M.skinneriana)和紫花含笑(M.crassipes)相近,但与野含笑的区别在于叶片倒卵形至倒卵状椭圆形,叶背面密被黄褐色茸毛,长5~7.5 cm,宽2.5~3.2 cm,先端尾尖,侧脉每边约6对,花被片椭圆形;与紫花含笑的区别在于花被片淡黄色,雌蕊群柄长3~4 mm。根据国际自然及自然资源保护联盟(IUCN)红色名录分类标准,尾叶含笑濒危等级为极度濒危。 相似文献
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通过比较观察紫花含笑(♀)和灰岩含笑(♂)及其杂种F1代叶表皮微形态和叶结构发现,紫花含笑和灰岩含笑在叶表皮微形态及叶解剖结构方面有很大差异。杂种F1代个体间在叶表皮微形态及叶解剖结构方面变异很大,为连续的数量遗传;其中57.7%以上的杂种F1代气孔密度高于父母本。杂种F1代矮化型植株叶片气孔密度较小,推测其抗寒性较强,可以通过进一步杂交改良,获得矮化型的盆栽含笑新品种。观察结果可为深入探讨含笑属种间杂种F1代的遗传变异,并从这些杂种F1代中选育观赏新品种积累科学资料。 相似文献
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紫花含笑(♀)与灰岩含笑(♂)及其杂种F1代叶表皮微形态和叶结构的比较观察 总被引:1,自引:1,他引:1
通过比较观察紫花含笑(♀)和灰岩含笑(♂)及其杂种F1代叶表皮微形态和叶结构发现,紫花含笑和灰岩含笑在叶表皮微形态及叶解剖结构方面有很大差异。杂种F1代个体间在叶表皮微形态及叶解剖结构方面变异很大,为连续的数量遗传;其中57.7%以上的杂种F1代气孔密度高于父母本。杂种F1代矮化型植株叶片气孔密度较小,推测其抗寒性较强,可以通过进一步杂交改良,获得矮化型的盆栽含笑新品种。观察结果可为深入探讨含笑属种间杂种F1代的遗传变异,并从这些杂种F1代中选育观赏新品种积累科学资料。 相似文献
5.
对紫花含笑(Michelia crassipes)、灰岩含笑(M.calcicola)及其杂种F1代花粉生活力进行了研究,为基于紫花含笑和灰岩含笑杂种F1代的含笑属观赏植物新品种培育与种质创新提供科学数据及研究资料.研究发现,亲本(紫花含笑和灰岩含笑)新鲜花粉萌发率均可达90%以上,杂种F1代花粉萌发率从38%到79%... 相似文献
6.
几种含笑属(木兰科)植物的花粉形态 总被引:3,自引:0,他引:3
含笑属 ( Michelia) 4种花粉光镜下形态相似。SEM下观察 ,黄兰 ( M.champaca)和金叶含笑 ( M.foveolata)表面雕纹为小穿孔 ,苦梓含笑 ( M.balansae)为小穴 ,野含笑 ( M.skinner-iana)为细皱纹 ,较粗糙。 TEM下观察 ,4种花粉外壁均可分为覆盖层、柱状层和基层。其中黄兰的柱状层结构较原始 ,金叶含笑的较进化。花粉形态在一定程度上可反映类群的系统演化。 相似文献
7.
遮荫处理下多脉青冈和金叶含笑的叶解剖结构变化研究 总被引:7,自引:1,他引:6
运用结构植物学方法,以多脉青冈(Cyclobalanopsis multinervis)和金叶含笑(Michelia foveolata)2年生苗为材料,进行全光照处理和遮荫处理下叶结构观察比较。结果显示,长期遮荫处理下,多脉青冈和金叶含笑新生叶的表皮细胞变薄,栅栏组织变得稀疏,层数有减少趋势,海绵组织更加疏松;多脉青冈的叶角质层退化。表明长期的弱光照下,2种树种的新生叶叶结构产生了适廊性的变化,其适应程度可以推测植物对光环境变化的适应能力强弱和进化潜力,研究结果对预测园林树种的光适应能力和结构进化有一定意义。 相似文献
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含笑属叶片的比较解剖学研究 总被引:4,自引:2,他引:2
对中国含笑属 ( Michelia) 1 8种 (包括观光木 1 ) ) ,1变种的叶片进行了比较解剖学研究 ,结果表明 :( 1 )含笑属植物的叶片均有明显的栅栏组织和海绵组织之分 (除石碌含笑和观光木外 ) ,但二者的厚度及它们在叶肉中的所占的比例在组间、种间有一定的差别 ;( 2 )有些种类叶片的上表皮有下皮 ,有些则无 ,少数种类 (石碌含笑 )上、下表皮皆有下皮 ;( 3)表皮毛的有无及表皮毛的细胞个数有一定的种间差别 ;( 4 )叶表皮角质层的厚薄程度在种间有一定的差别 ;( 5 )油细胞在含笑属植物叶片整个叶肉中普遍存在 (除含笑只在栅栏组织中有分布 ) ,但其分布密度在种间有较大的差异。通过对含笑属植物叶片结构的比较观察 ,旨在探讨该属间的系统演化关系 ,为分组、分种提供解剖学方面的实验证据 相似文献
9.
深山含笑传粉生物学研究 总被引:3,自引:0,他引:3
为明确深山含笑(Michelia maudiae)的传粉生物学特性,该文以西华师范大学校园内的深山含笑为研究材料,采取野外观察法记录了深山含笑的开花动态、访花者及访花频率;用游标卡尺法,测定了深山含笑的异交指数(OCI);用醋酸洋红法,测定了花粉胚珠比(P/O);用套袋和人工授粉法,测定了深山含笑的繁育系统。结果表明:(1)深山含笑为早春开花植物,其种群花期为2~3月,持续30d左右,单花花期5~6d;在单花开放初期,最内层的花瓣未绽开,是适应潮湿或多雨的环境而保护花药与柱头免受雨水的冲刷,提高雌雄性适合度,确保繁殖成功的一种策略;(2)深山含笑的有效传粉者为蜜蜂,访花时间集中在晴朗天气的中午;(3)深山含笑的异交指数(OCI)等于5,花粉胚珠比(P/O)为2 933±50;(4)深山含笑为雄蕊先熟,柱头可授性在开花第2~3天达到最高;(5)套袋和人工授粉表明深山含笑为兼性自交和异交授粉,其中异交授粉的座果率和结籽率显著高于自交授粉。早春开花的深山含笑,其传粉者为单一的蜜蜂,繁育系统为异交,部分自交亲和,结果为引种栽培、良种选育等提供依据更好地利用和保护此资源奠定基础。 相似文献
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《Ibis》1990,132(2):329-342
Books reviewed in this article: Antas , P.T.Z. & Cavalcanti , R.B. 1988. Aves Comuns do Planalto Central. Chandler , R.J. 1989. The Macmillan Field Guide to North Atlantic Shorebirds. Clutton -Brock , T.H. (ed.). 1988. Reproductive Success: studies of individual variations in contrasting breeding systems. Delin , H. & Svensson , L. 1988. Photographic Guide to the Birds of Britain and Europe. Dunning , J.S. 1987. South American Birds—a photographic aid to identification. Ewans , M. 1989. Bharatpur Bird Paradise. Frugis , S., Malaguzzi , G., Vicini , G. & Cristina , Grimmett , R.F.A. & Jones , T.A. (eds) 1989. Important Bird Areas in Europe. Hutchinson , C.D. 1989. Birds in Ireland. Iapichino , C. & Massa , B. 1989. The Birds of Sicily. Kilham , L. 1989. The American Crow and the Common Raven. Kooyman , G.L. 1989. Diverse Divers: physiology and behaviour. Mearns , B. & Mearns , R. 1988. Biographies for Birdwatchers Mingozzi , T., Boano , G., Pulcher , C. & Collaborators. Poole , A. 1989. Ospreys: a Natural and Unnatural History. Pringle , J.D. 1987. The Shorebirds of Australia. Rheinwald , G., Ogden , J. & Schulz , H. (eds) 1989. Weißstorch: Status und Schutz. White Stork: Status and Conservation. Roughgarden , J., May , R.M. & Levin S.A. 1989. Perspectives in Ecological Theory. Sheail , J. 1985. Pesticides and Nature Conservation—The British Experience 1950–1975. Stalmaster , M. 1987. The Bald Eagle. Turner , A. & Rose , C. 1989. A Handbook to the Swallows and Martins of the World. Viksne , J. (ed.) 1989. Latvian Breeding Bird Atlas 1980–1984 (in Latvian, Russian and English). Ashmole , M. & P. 1989. Natural History Excursions in Tenerife. Axelson , R.D. 1989. Caring for Your Pet Bird. Bauer , K. 1989. Rote Listen der Gefährdeten Vögel und Säugetiere Österreichs und Verzeichnisse der in Österreich vorkommenden Arten. Bircham , P. 1989. The Birds of Cambridgeshire Boyd , H. & Pirot , J.-Y. (eds) 1989. Flyways and Reserve Networks for Waterbirds. Brasseler , H. 1987. Bibliography of Ornithological Bibliographies II. Donkin , R.A. 1989. The Muscovy Duck Cairina moschata domestica. Elliott , R.E. 1989. Birds of Islay. Flint , V.E., Boehme , R.L., Kostin , Y.V. & Kuznetsov , A.A. 1989. A Field Guide to the Birds of the USSR. Translated from the Russian by N. Bourso-Leland. Holmgren , V.C. 1986. The Way of the Hummingbird. Hulm , P. (ed.) 1989. World Wildlife Conservation Yearbook 1987/88. Inskipp , T., Broad , S. & Luxmoore , R. (eds) 1988. Significant Trade in Wildlife: A review of the Selected Species in CITES Appendix II. Volume 3: Birds Kofalk , H. 1989. No Woman Tenderfoot. Florence Merriam Bailey, Pioneer Naturalist. Kondratiev , A. Ya. 1989. Bulletin of the Working Group on Waders (in Russian). Lohmann , M. & Haarmann , K. 1989. Vogelparadiese—122 Biotope zwischen Wattenmeer und Bodensee. Lorand , S. & Atkin , K. 1989. The Birds of Lincolnshire and South Humberside. Monval , J.-Y. & Pirot , J.-Y. (rds) 1989. Results of the IWRB International Waterfowl Census 1967–1986. Moss , S. 1988. Natural History of the Antarctic Peninsula. Ogilvie , M. & Winter , S. (eds) 1989. Best Days with British Birds. Orton , D.A. 1989. The Hawkwatcher. Adventures among birds of prey in the wild. Paynter , R.A. Jr. 1989. Ornithological Gazetteer of Paraguay. 2nd ed. Pemberton , J.E. (ed.) 1989. The Birdwatcher's Yearbook and Diary 1990. Pickford , P. & B., & Tarboton , W. 1989. African Birds of Prey. Reilly , P. 1988. The Lyrebird. Santa Barbara Software Products 1988. World Birdbase: Users Manual. Santa Barbara: Santa Barbara Software Products. Schembri , P.J. & Sultana , J. (ed.) 1989. Red Data Book for the Maltese Islands. Scottish Chouch Study Group . 1989. Choughs and Land-use in Europe. Van Someren , G.R. Cunningham & Van Someren , L.A. 1989. Van Somerens' Birds I. 相似文献
13.
Liu S Shiotani B Lahiri M Maréchal A Tse A Leung CC Glover JN Yang XH Zou L 《Molecular cell》2011,43(2):192-202
The ataxia telangiectasia-mutated and Rad3-related (ATR) kinase is a master checkpoint regulator safeguarding the genome. Upon DNA damage, the ATR-ATRIP complex is recruited to sites of DNA damage by RPA-coated single-stranded DNA and activated by an elusive process. Here, we show that ATR is transformed into a hyperphosphorylated state after DNA damage, and that a single autophosphorylation event at Thr 1989 is crucial for ATR activation. Phosphorylation of Thr 1989 relies on RPA, ATRIP, and ATR kinase activity, but unexpectedly not on the ATR stimulator TopBP1. Recruitment of ATR-ATRIP to RPA-ssDNA leads to congregation of ATR-ATRIP complexes and promotes Thr 1989 phosphorylation in trans. Phosphorylated Thr 1989 is directly recognized by TopBP1 via the BRCT domains 7 and 8, enabling TopBP1 to engage ATR-ATRIP, to stimulate the ATR kinase, and to facilitate ATR substrate recognition. Thus, ATR autophosphorylation on RPA-ssDNA is a molecular switch to launch robust checkpoint response. 相似文献
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C. D. Therrien D. L. Ritch L. S. Sujkowski L. J. Spielman W. E. Fry S. S. Daggett J. H. Sim P. W. Tooley 《Journal of Phytopathology》1993,139(1):68-80
Isolates of Phytophthora infestans were collected from all potato growing regions of Poland during the blight seasons of 1987—1989. All 1987 isolates were of Al mating type and were sensitive to metalaxyl. In 1988 and 1989, 46.5 % and 55.3 % of the isolates were sensitive to metalaxyl, respectively. The percentage of highly resistant (R) isolates increased from 25.6 % in 1988 to 39.5 % in 1989; however the percentage of intermediately resistant (I) isolates decreased during that period from 27.9 % to 5.3 %. A significant association was observed between the A1 compatibility type and metalaxyl resistance. The A2 mating type first appeared in 1988, and its frequency increased from 4.7 % of the population in 1988 to 47.6 % in 1989. Coincident with this change in mating type frequency, changes in ploidy levels of isolates were observed. Whereas 3 % of the 1988 isolates were diploid, 90 % of the 1989 A2 isolates and 28.6 % of the 1989 Al isolates were diploid. The approximate 1:1 ratio of the two mating types encountered in 1989, and the predominance of diploidy, indicates that the Polish population of P. infestans has the potential to become sexual. 相似文献
15.
Estimations of bacterioplankton production and biomass werecarried out in enclosure experiments during two consecutiveyears (1989 and 1990) in oligotrophic clearwater Lake Njupfatet.The lake was limed in November 1989, and the experiments werecarried out both in 1989 (unlimed) and in 1990 (limed). Bags(3001) were manipulated with inorganic phosphorus and nitrogen,organic carbon, and metazoan zooplankton abundance. Both years,bacterial production was stimulated by inorganic nutrients aloneand in combination with organic carbon. However, the increasein bacterial production when inorganic nutrients were addedalone was much stronger in 1990 than in 1989. In 1989. bacterialproduction increased strongly only when inorganic nutrientsand organic carbon were added together. The phytoplankton communitywas dominated by the cyanobacterium Merismopedia tenuis-simaduring 1989, and the phytoplankton biomass increased only slightlywhen receiving inorganic nutrients. In 1990, when the lake hadbeen limed. M.tenuissima had completely disappeared and thephytoplankton community, dominated by Chrysophyceae and Chlorophyceae,responded strongly to additions of inorganic nutrients. Theincreased phytoplankton productivity in 1990 may have resultedin increased release of organic carbon, and this in turn thatthe carbon limitation of bacterioplankton production decreasedfrom 1989 to 1990. Zooplankton had a positive effect on bacterioplanktonproduction in 1989, but no effect in 1990. The loss of bacterialbiomass approximated 60% of the bacterial production in 1989,while in 1990 it almost equalled the bacterioplankton production. 相似文献
16.
《Ibis》1990,132(3):488-496
Books reviewed in this article:
B ohlen , D.H. 1989. The Birds of Illinois.
B undy , G., C onnor , R.J. & H arrison , C.J.O. 1989. Birds of the Eastern Province of Saudi Arabia.
D wenger , R. 1989. Die Dohle. Pp. 148, 40 black-and-white photographs, maps.
D ymond , J.N., F raser , P.A. & G antlett , S.J.M. 1989. Rare Birds in Britain and Ireland.
Fa aborg , J. 1988. Ornithology. An ecological approach.
G ill , F.B. 1990. Ornithology.
F ord , H.A. 1989. Ecology of Birds: An Australian perspective.
G ill , F.B. 1990. Ornithology.
G onzales , P.C. & R ees , C.P. 1988. Birds of the Philippines.
G uraya , S.S. 1989. Ovarian Follicles in Reptiles and Birds.
M c I ntyre , J.W. 1988. Spirit of the Northern Lakes: the Common Loon.
N ewton , I. (ed.) 1989. Lifetime Reproduction in Birds.
O tte , D. & E ndler , J.A. 1989. Speciation and its Consequences.
O uellet , H. (ed.) 1989. Acta XIX Congressus Internationalis Ornithologici, Volumes 1 & 2.
P ennycuick , C.J. 1989. Bird Flight Performance: A practical calculation manual.
P eterjohn , B.G. 1989. The Birds of Ohio.
P range , H. 1989. Der Graue Kranich.
S icutch , A.F. 1989. Birds Asleep.
T homson , M.C. & E ly , C. 1989. Birds in Kansas
B ohlen , D.H. 1989. The Birds of Illinois.
P eterjohn , B.G. 1989. The Birds of Ohio.
Voous, K.H. 1988. Owls of the Northern Hemisphere.
V uilleumier , F. & M onasterio , M. (eds.) 1986. High Altitude Tropical Biogeography. 相似文献
B ohlen , D.H. 1989. The Birds of Illinois.
B undy , G., C onnor , R.J. & H arrison , C.J.O. 1989. Birds of the Eastern Province of Saudi Arabia.
D wenger , R. 1989. Die Dohle. Pp. 148, 40 black-and-white photographs, maps.
D ymond , J.N., F raser , P.A. & G antlett , S.J.M. 1989. Rare Birds in Britain and Ireland.
Fa aborg , J. 1988. Ornithology. An ecological approach.
G ill , F.B. 1990. Ornithology.
F ord , H.A. 1989. Ecology of Birds: An Australian perspective.
G ill , F.B. 1990. Ornithology.
G onzales , P.C. & R ees , C.P. 1988. Birds of the Philippines.
G uraya , S.S. 1989. Ovarian Follicles in Reptiles and Birds.
M c I ntyre , J.W. 1988. Spirit of the Northern Lakes: the Common Loon.
N ewton , I. (ed.) 1989. Lifetime Reproduction in Birds.
O tte , D. & E ndler , J.A. 1989. Speciation and its Consequences.
O uellet , H. (ed.) 1989. Acta XIX Congressus Internationalis Ornithologici, Volumes 1 & 2.
P ennycuick , C.J. 1989. Bird Flight Performance: A practical calculation manual.
P eterjohn , B.G. 1989. The Birds of Ohio.
P range , H. 1989. Der Graue Kranich.
S icutch , A.F. 1989. Birds Asleep.
T homson , M.C. & E ly , C. 1989. Birds in Kansas
B ohlen , D.H. 1989. The Birds of Illinois.
P eterjohn , B.G. 1989. The Birds of Ohio.
Voous, K.H. 1988. Owls of the Northern Hemisphere.
V uilleumier , F. & M onasterio , M. (eds.) 1986. High Altitude Tropical Biogeography. 相似文献
17.
Networks and the best approximation property 总被引:28,自引:0,他引:28
Networks can be considered as approximation schemes. Multilayer networks of the perceptron type can approximate arbitrarily well continuous functions (Cybenko 1988, 1989; Funahashi 1989; Stinchcombe and White 1989). We prove that networks derived from regularization theory and including Radial Basis Functions (Poggio and Girosi 1989), have a similar property. From the point of view of approximation theory, however, the property of approximating continuous functions arbitrarily well is not sufficient for characterizing good approximation schemes. More critical is the property ofbest approximation. The main result of this paper is that multilayer perceptron networks, of the type used in backpropagation, do not have the best approximation property. For regularization networks (in particular Radial Basis Function networks) we prove existence and uniqueness of best approximation. 相似文献
18.
Changes in ovarian morphology, brain gonadotropin-releasing hormone (GnRH), plasma estradiol, and progesterone were examined during the 1988 and 1989 spawning migrations of the adult female sea lamprey, Petromyzon marinus. There were significant increases through time in brain GnRH (1989) and plasma estradiol (1988 and 1989), with progesterone levels fluctuating (1988 and 1989) during the freshwater phase of the spawning migrations. In 1989, brain GnRH and plasma estradiol levels gradually increased through time until just prior to spawning when levels decreased. During 1988, there were no significant changes in GnRH, which may reflect lower temperatures in that year. These data provide new information on brain GnRH during the final maturational processes in the female sea lamprey. 相似文献
19.
《Letters in applied microbiology》1990,11(6):297-300
Book reviewed in this article:
GENETIC TRANSFORMATION AND EXPRESSION (1989). Edited by L.O. Butler, Colin Harwood & B.E.B. Moseley.
MICROBIAL RESISTANCE TO DRUGS (1989). Edited by L.E. Bryan.
MEDICAL PARASITOLOGY (1989). By G. Piekarski.
LECTINS (1989). By N. Sharon & H. Lis.
MYCOBACTERIAL SKIN DISEASES (1989). Edited by M. Harahap. 相似文献
GENETIC TRANSFORMATION AND EXPRESSION (1989). Edited by L.O. Butler, Colin Harwood & B.E.B. Moseley.
MICROBIAL RESISTANCE TO DRUGS (1989). Edited by L.E. Bryan.
MEDICAL PARASITOLOGY (1989). By G. Piekarski.
LECTINS (1989). By N. Sharon & H. Lis.
MYCOBACTERIAL SKIN DISEASES (1989). Edited by M. Harahap. 相似文献
20.
《Letters in applied microbiology》1990,11(1):52-54
Book reviewed in this article:
INFECTION IN THE ORTHOPAEDIC PATIENT (1989). Edited by R. Coombs & R.H. Fitzgerald Jr.
MOLECULAR MECHANISMS OF MICROBIAL ADHESION (1989). Edited by L. Switalski, M. Hook & E.H. Beachey.
NEW STRATEGIES FOR ORAL IMMUNIZATION (1989). Current Topics in Microbiology and immunology 146. Edited by J. Mestecky & J.R. McGhee.
BIOHAZARDS MANAGEMENT HANDBOOK (1989). Edited by Daniel F. Liberman & Judith G. Gordon.
ASPERGILIUS SPECIES ON STORED PRODUCTS (1989). By Z. Kozakiewicz.
FOODBORNE BACTERIAL PATHOGENS (1989). Edited by M.P. Doyle. 相似文献
INFECTION IN THE ORTHOPAEDIC PATIENT (1989). Edited by R. Coombs & R.H. Fitzgerald Jr.
MOLECULAR MECHANISMS OF MICROBIAL ADHESION (1989). Edited by L. Switalski, M. Hook & E.H. Beachey.
NEW STRATEGIES FOR ORAL IMMUNIZATION (1989). Current Topics in Microbiology and immunology 146. Edited by J. Mestecky & J.R. McGhee.
BIOHAZARDS MANAGEMENT HANDBOOK (1989). Edited by Daniel F. Liberman & Judith G. Gordon.
ASPERGILIUS SPECIES ON STORED PRODUCTS (1989). By Z. Kozakiewicz.
FOODBORNE BACTERIAL PATHOGENS (1989). Edited by M.P. Doyle. 相似文献