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 562 毫秒
1.
祁连山保护区种子植物属的区系研究   总被引:5,自引:0,他引:5  
祁连山自然保护区位于甘肃西南部,祁连山北坡,北纬36°45′—39°30′,东经93°31′—102°40′,面积272.2万hm2,属青藏高原、黄土高原和蒙古高原的过渡带;分布有种子植物1286种,隶属84科431属,占中国种子植物科数的30.43%,属数的13.86%,种数的5.00%。含20种以上的属6属155种,含10-19种的属19属244种,含5-9种的属45属292种,含1-4种的属360属595种,其中,含1种的属217属217种。属的分布类型有12个分布类型和18个分布亚型,热带分布类型有3个类型、1个变型,共27属44种,占祁连山保护区总属数的6.26%;北温带分布及其变型在本区共173属,占本区属数的40.14%,其中北温带分布类型在本区共126属,占29.23%,为本区最大的分布类型;旧世界温带分布及其变型共64属,其中在旧世界温带分布的54属植物中,鹅观草属(Roegneria C.Coch.)为本区最大的属,共15种;地中海区、西亚至中亚分布及其变型共34属,其中地中海区、西亚至中亚分布在祁连山保护区均为含1—5种的小属;中亚分布及其变型共有24属,其中中亚分布中,除(Dilophia Thoms)和小甘菊属(Cancrinia Kar.et Kir.)各有3种外,其余11属均仅含1种;中国特有分布共9属10种,这些特有成分中,有青藏高原特有属(黄缨菊Xanthopappus C.Winkl.)、唐古特地区的特有属(穴丝荠属Coelonema Maxim.),大部分为本区与周围地区所共有的属,而无真正的本区特有属。温带成分占优势,植物区系年轻,草本植物丰富而乔木种类贫乏,特有属、种少,地理成分沿海拔高度明显不同。  相似文献   

2.
科克苏湿地自然保护区共有维管束植物65科259属551种,与西北其它荒漠地区相比,植物种类非常丰富.该区维管束植物科的组成以寡种科和区域性单种科为主,占总科数的66.2%,菊科、禾本科等较大科仅占总科数的15.4%,但所含物种数达到63%,在本区植物种的组成中占据重要地位;属的组成以小型属和区域性单种属占优,占植物总属数的94.6%.植物生活型以地下芽植物占绝对优势,达到40.1%,其次为一年生植物,为35.8%,这种组成比例与科克苏湿地的环境条件有着密切的关系.所有种子植物分属于11个分布区类型,以北温带、地中海与西亚、中亚和旧世界温带成分占明显优势,反映出该区植物分布的北温带性质,同时与地中海、西亚和中亚植物区系关系极为密切.  相似文献   

3.
中国新源县山地草甸类草地自然保护区,约有种子植物364种,隶属于48科,203属,根据该我植物区系的分析,各大科,属的地理成分及主要群落的优势种,以温带成分占明显的优势,但是由于保护区特定的地理位置,同时也反映出它成为温带亚洲分布,地中海,西亚至中亚分布和中亚分布等类型的交汇地带,赋于植物区系成分以复杂性。  相似文献   

4.
托木尔大峡谷位于暖温带干旱气候区,地处天山托木尔峰南坡的暖温带灌木荒漠和温带荒漠草原带。共分布野生种子植物35科102属131种(变种)。植物寡种科占绝对优势,单种科位居其二;超过10种的较大科仅有4科,占总科数的11.43%,所含属、种数分别占本区总属、种数的50.00%和53.43%;科的地理区系成分以温带成分(热带至温带、亚热带至温带、温带)为主(18科,51.43%)。植物属均为单种属或寡种属,其中单种属占绝对优势;在属的分布类型中,以北温带分布类型及其变型为主,其次是旧世界温带分布类型及其变型,地中海、西至中亚分布类型及其变型位居第三,热带成分极其微弱。特有种、珍稀种以及重点保护植物共20种,比例较高。  相似文献   

5.
新疆沙冬青群落的区系组成与结构特征   总被引:12,自引:5,他引:12  
在乌恰县不同分布地点的新疆沙冬青群落中随机设置10个样方,对新疆沙冬青群落种子植物的科、属、种的组成及其结构特征进行调查.结果表明:新疆沙冬青群落由22科39属62种种子植物组成,群落物种较为丰富,科的区系以世界分布类型为主,属的区系以地中海-中亚-西亚成分为主,区系地理成分古老而复杂.新疆沙冬青群落的水平结构,大部分植物以丛生形式在群落中聚集分布,少数植物散生于群落中;群落的垂直结构,按生长型可分为2层(灌木层、草本层)和6个层片,构成新疆沙冬青群落的植物,其中草本和半灌木种类较多,所占的比例较大.群落中草本层片占植被总覆盖度的15%~31%,新疆沙冬青群落属于草原化荒漠植被类型.  相似文献   

6.
贺学礼 《杂草学报》1995,9(1):14-17
陕西农田杂草种类繁多,据调查共有332个种,分属54个科、205个属。其区系成份多样,其中温带尬 分有79个属,占38.5%;世界分布有49个属,占23.9%;热带成份有48个属,占23.4%;地中海-西亚-中亚成份有10个属,占4.9%;中亚成份有5个属,占2.4%;东亚-北美洲际成份有4个属,占2.0%;东亚成份有10个属,占4.9%。  相似文献   

7.
经初步查明,新疆乌恰县康苏肖尔布拉克自然保护区计种子植物65科282属635种(含亚种、变种),裸子植物3科3属12种,被子植物62科279属623种。对282属635种种子植物的地理成分分析表明,该地区植物分布区类型有12个型14个变型。其中,北温带分布有95属259种,占该地区植物总属、种数的40.25%和53.40%,表明温带属性是该地区植物区系的基本特点。同时,该地区植物区系与地中海―西亚―中亚及旧世界温带交流最多,其次与热带有一定的交流,而与温带亚洲和东亚交流很少。  相似文献   

8.
中国帕米尔高原种子植物属的区系研究   总被引:3,自引:2,他引:1  
中国帕米尔高原座落于新疆西南部,北纬37°-39,°东经73°-76,°面积约30000km2,区内平均海拔约4000m,拥用种子植物963种(包括变种),分属于59科303属,其中裸子植物3科3属12种,被子植物56科300属951种。种子植物属的区系特征如下:1)单种属、少种属占极高的比例,属种比值偏高,植物区系组成复杂,2)属级水平分析表明,本区植物区系以北温带为主的温带成分占主导地位,仅有13个从热带分布区延伸到温带的热带属,且在本区所含种类极少,但丰富了本区植物区系的组成,3)植物区系较为年轻且有一定的衍生性,4)高原生态因子的作用,使本区植物获得了适应寒冷和干旱的特性。  相似文献   

9.
中国-巴基斯坦喀喇昆仑公路沿线植物区系   总被引:3,自引:0,他引:3  
2009年9月对中巴喀喇昆仑公路沿线分布的植物和植被进行了考察,经初步整理和统计,该地区共有野生维管束植物52科223属489种。其中,蕨类植物1科1属1种,裸子植物2科2属5种,被子植物49科220属483种。对222属488种种子植物的地理成分分析表明,该地区植物分布区类型有10个正型13个变型。其中,北温带分布有86属227种,占该地区植物总属、种数的45.75%和61.36%,表明温带属性是该地区植物区系的基本特点。同时,该地区植物区系与地中海-西亚-中亚及旧世界温带交流最多,其次与热带有一定的交流,而与温带亚洲和东亚交流很少。  相似文献   

10.
北塔山为中蒙边境的界山,地处新疆境内,属典型干旱山区,植物种类贫乏,区内珍稀濒危植物共计21种,隶属16科16属。其中,国家重点保护野生植物8种,中国物种红色名录收录6种,新疆重点保护野生植物15种;珍稀濒危种子植物区系分布区类型以北温带成分为主,与地中海、西亚至中亚分布及其变型联系紧密,中亚分布类型有微弱渗入;珍稀濒危种水平分布西多东少,集中分布于海拔900~2 000 m,且以旱生灌木、半灌木为主,仅有少量中生和湿生植物。  相似文献   

11.
Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.  相似文献   

12.
We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.  相似文献   

13.
Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.  相似文献   

14.
Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.  相似文献   

15.
《干旱区科学》2014,(6):782-782
正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad  相似文献   

16.
Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.  相似文献   

17.
Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F 3, F 4 and F 5, but not in F 1 and F 2 that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F 1 and F 2 in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.  相似文献   

18.
Solacol®, a formulation of the antibiotic validamycin, at 0.33% in 2% malt extract agar, reduced the spread of fungi on dilution plates drastically and allowed twice as much incubation time before subculturing; this resulted in an elevated number of species isolated. Using pure cultures of 62 common soil fungi, it was shown that all fast-growing species (exceptPythium ultimum) were efficiently inhibited but not completely suppressed. Inhibition was comparable to that by 0.5% oxgall, though, while this substance completely suppressed several species, Solacol very strongly inhibited onlyGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum andRhizoctonia solani. In a further experiment each separate constituent of Solacol was tested against 22 fungi at equivalent concentrations. Validamycin strongly inhibitedChaetomium globosum and two Basidiomycetes, though hardly more than the non-ionic detergent which mainly inhibited the other fungi. A few species were, however, more inhibited by Solacol than by the detergent alone. Solacol at 0.33% is a suitable aid in dilution plating of soil fungi, by increasing the number of colonies and species observed.Samenvatting Solacol®, een formulering van het antibioticum validamycine, remde de groei van schimmels in verdunningsplaten met een concentratie van 0.33% in 2% moutagar en maakte het mogelijk de periode tot afenten met een factor 2 te verlengen; daardoor was het aantal geïsoleerde soorten duidelijk toegenomen. Met reincultures van 62 algemene grondschimmelsoorten werd aangetoond, dat alle snelgroeiende soorten (met uitzondering vanPythium ultimum) voldoende geremd, maar niet volkomen onderdrukt werden. Het remmingspercentage was vergelijkbaar met dat van 0.5% ossegal, hoewel dit laatste sommige soorten volkomen onderdrukte; Solacol remde alleenGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum enRhizoctonia solani zeer sterk. In een volgend experiment werden de componenten van Solacol t.o.v. 22 fungi apart getoetst in concentraties equivalent aan 0.33% Solacol. Validamycine remde alleenChaetomium globosum en twee basidiomyceten behoorlijk, maar nauwelijks meer dan de niet-ionische uitvloeier, die in hoofdzaak de overige remeffecten veroorzaakte. Enkele soorten werden echter door het complete Solacol veel sterker geremd dan door de uitvloeier alleen. Solacol in een verdunning van 0,33% wordt aanbevolen bij verdunningsplaten voor het isoleren van grondschimmels ten einde het aantal kolonies en soorten te verhogen.  相似文献   

19.
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.  相似文献   

20.
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