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 56 毫秒
1.
于2015年10—12月,在新疆布尔根河狸国家级自然保护区对社区牧民保护蒙新河狸的意识和态度进行了问卷调查。结果表明:(1)该保护区4个村社区牧民对蒙新河狸的认识存在显著的差异,但对保护蒙新河狸及栖息地持有肯定的态度;(2)随着距蒙新河狸活动核心区距离的增加,蒙新河狸与家畜争夺草场的矛盾逐渐减弱;(3)社区牧民保护蒙新河狸的认识和态度与各村落到核心区的距离具有相关性;(4)社区牧民对蒙新河狸等野生动物保护法律法规普遍了解较少,需要采取科学合理的管护措施,更好地协调社区发展与保护蒙新河狸之间的关系。  相似文献   

2.
基于SPOT NDVI的阿尔金山自然保护区植被动态变化研究   总被引:2,自引:0,他引:2  
气候变化对陆地生态系统,特别是高寒地区植被的影响是全球变化研究的重要方面。利用1998-2008年SPOT VGT [WTBX]NDVI[WTBZ]植被指数,分析了阿尔金山[WTBX]NDVI[WTBZ]时空变化特征及其与主要气候因子(气温、降水)的相关关系。结果表明:保护区平均[WTBX]NDVI[WTBX]年内季节变化明显,[WTBX]DN[WTBZ]变化幅度在33~53,5月开始较快上升,最高值出现在9月,其多年平均值为40,总体上呈先下降后上升的趋势。从空间分布上看,[WTBX]NDVI[WTBZ]的高值主要集中在阿雅克湖流域,特别是卡尔敦检查站附近。趋势分析表明,除河流、湖泊附近的植被有所退化外,保护区内部植被总体上有所改善,气温和降水与[WTBX]NDVI[WTBZ]线性相关显著;而保护区边缘植被有不同程度的退化,人类活动或许是植被退化的诱导因素。  相似文献   

3.
利用卫星监测和反演沙尘天气频率或沙尘气溶胶光学厚度,检验卫星监测和反演结果是否与地面观测一致。采用地面观测记录获得全部沙尘天气事件频数([WTBX]DF[WTBZ])资料,对1979-2002年TOMS(臭氧总量绘图系统)反演的气溶胶光学厚度指数([WTBX]AI[WTBZ])进行检验分析。结果表明:① [WTBX]AI[WTBZ]高值区基本与我国北方地面观测的沙尘天气频数高值分布区一致,两者均在我国西北部极端干旱的盆地和高原地区出现最高值,相对低值一般分布在气候湿润的东部地区,但东北平原和华北平原[WTBX]AI[WTBZ]值相对较高,冬季尤其明显,与地面沙尘观测差异很大;② [WTBX]AI和DF[WTBZ]年内变化也具有很高的一致性,均在春季最大,4月达到峰值以后减小,但前者在冬季12月和1月出现次高值,而后者冬季为全年低谷;③ 相关性分析表明,[WTBX]AI和DF[WTBZ]相关系数一般在夏季最大,冬季最小,年和季节的相关系数具有随时间呈下降的趋势;④ TOMS [WTBX]AI[WTBZ]数据在反映我国北方沙尘天气频数时空变化特征方面,区域上西北干旱区效果最好,东部季风区的华北和东北较差;季节上夏季、初秋和春季较好,冬季效果较差。同时还对[WTBX]AI和DF[WTBZ]资料时空分布差异的可能原因及其潜在应用意义进行了讨论。  相似文献   

4.
植物次生物质2-十三烷酮能够诱导棉铃虫细胞色素P450 [WTBX]CYP6B[WTBZ]6基因的过量表达,以6龄棉铃虫([WTBX]Helicoverpa armigera[WTBZ])幼虫为对象,研究2-十三烷酮对棉铃虫细胞色素P450 CYP6B6的诱导作用,并对其表达规律进行了初探。分别采用实时荧光定量PCR(qRT PCR)和免疫组化的方法,分析棉铃虫在终浓度为10 mg·g-1 的2-十三烷酮胁迫下,不同时间及不同组织部位[WTBX]CYP6B[WTBZ]6 基因在mRNA水平和蛋白水平上的表达变化规律。qRT PCR结果显示:用添加了2-十三烷酮的人工饲料饲喂棉铃虫不同时间后,在头壳中[WTBX]CYP6B[WTBZ]6 mRNA的表达量一直低于对照组,到48 h时与对照组具有显著差异([WTBX]t4=15.32,P[WTBZ]=0.000 1);在脂肪体中随着时间的推移,表达量呈升高趋势,在36 h 已过量表达([WTBX]t4=7.627,P[WTBZ]=0.001 6);在24 h时体壁和中肠组织的表达量分别较对照组提高了2.06倍和7.16倍,之后表达量均呈现先降低后升高的趋势,且在48 h时达到最大。免疫组化结果显示:在棉铃虫幼虫组织中发现CYP6B6蛋白在体壁、脂肪体、中肠中均有表达,相比之下在体壁中表达量较高。该研究为深入了解棉铃虫P450 CYP6B6的表达调控机制及其参与杀虫剂抗性的研究奠定了基础。  相似文献   

5.
通过红外相机陷阱技术,对新疆卡拉麦里有蹄类自然保护区乔木希拜区域野放普氏野马天敌狼的活动节律进行了研究。结果发现,不同月份狼的日活动差异指数α和昼行性指数β均存在极显著差异(α指数:t=8.009,df=7,P<0.01;β指数:t=13.526,df=7,P<0.01),且β=0.45<13/24,表明在研究区狼为夜行性动物。2011年、2012年和2013年季节活动峰型存在显著差异(2011年: χ2=13.087,df=2,P=0.041 1;2012年: χ2=12.452,df=2,P=0.023 4;2013年: χ2=18.998,df=2,P=0.032 6),因此,不同年份不同季节狼的活动节律存在差异。  相似文献   

6.
在石羊河上游地区选择4个样点,采集160余根青海云杉样芯,经过固定、打磨、交叉定年和测量等工作,建立研究区的树轮宽度年表。利用美国NASA戈达德航天中心的GIMMS/NDVI数据,建立研究区1982-2006年逐月标准化植被指数(NDVI)序列。发现研究区NDVI年内变化为单峰型,5-8月为生长季,年际间变化则有波动减少的趋势。经过相关性分析后发现,树轮年表与非生长季(上一年9月到当年4月)降水呈显著正相关,非生长季[WTBX]NDVI[WTBZ]与非生长季的降水呈较明显负相关。分析NDVI与年表关系后发现,生长季[WTBX]NDVI[WTBZ]与树轮年表相关性较差,而非生长季NDVI与年表相关性较好且为负相关(r=-0.667,p<0.01)。  相似文献   

7.
管海英  赵鑫  靳佳  张思楠  徐璐 《干旱区研究》2014,31(6):1125-1131
土壤微生物作为荒漠生态系统中的重要分解者,对干旱区碳循环有着重要作用。以干旱区荒漠生态系统柽柳保护样地为对象,利用统计学与地统计学中的空间自相关方法,分析在自然状况下土壤微生物量碳及其影响因子之间的空间变异和响应特征,探讨柽柳荒漠生态系统的土壤微生物量空间分布特征及其控制机理。结果表明:土壤微生物量碳为14.1~1 178.6 μg•g-1,远小于其他生态系统;空间分布表现出植被覆盖越密集,土壤微生物量碳越大,且全局空间分布为正相关趋势,局部空间自相关指数Mora[JP8]n’[JP]s 〖WTBX〗I〖WTBZ〗为-0.2~0.5;土壤微生物量碳与土壤环境因子中的土壤水分[WTBX](W)、土壤温度(T)均呈显著正相关(P<0.05),[WTBZ]且空间相关系数分别为0.56和0.64。这些结果说明荒漠生态系统中土壤微生物量碳表现出强烈的空间异质性,且空间分布在10 m格网尺度(像元尺度)与植被覆盖度、温湿度显著相关,这些将有助于加强对干旱区土壤碳库空间格局的理解,从而制定更精细的土壤微生物量碳空间自相关的像元尺度。  相似文献   

8.
梭梭与白梭梭气体交换特征对比分析   总被引:3,自引:1,他引:2  
梭梭[WTBX](Haloxylon ammodendron)与白梭梭(H.persicum)[WTBZ]是古尔班通古特沙漠植物群落2个最主要的建群种。通过对梭梭与白梭梭光合特性及相关环境因子的同期观测,探讨其光合响应特征及其与环境因子关系的异同。结果表明:梭梭对弱光的利用能力大于白梭梭,而白梭梭利用强光的能力大于梭梭。梭梭和白梭梭净光合速率[WTBX](Pn)、气孔导度(Gs)、蒸腾速率(Tr)的日变化特征均为“单峰”型,但Pn、Gs峰值出现时间略有差异,Tr的峰值出现时间为16:00。根据梭梭和白梭梭Pn、胞间[WTBZ]CO2浓度[WTBX](Ci)及气孔限制值(Ls)的变化方向,推测梭梭光合“午休”主要由气孔因素引起。白梭梭日平均Pn、Tr和WUE(水分利用效率)均高于梭梭,说明白梭梭是一种高光合、高蒸腾、高水分利用效率的物种。相关分析表明,对梭梭、白梭梭的Pn影响最显著的环境因子是光量子通量密度(PPFD)。  相似文献   

9.
入侵植物刺苍耳对小麦和苜蓿种子的化感作用   总被引:2,自引:0,他引:2  
采用生物实验法,研究刺苍耳([WTBX]Xanthium spinosum[WTBZ])不同构件的水浸提液对小麦和苜蓿种子的化感效应。结果表明:刺苍耳植株不同构件的提取液对小麦和苜蓿种子的萌发均具有较强的抑制作用,而根、茎和叶水浸液产生显著抑制作用的起始浓度分别为0.012 50 g·mL-1,且化感作用随浸提液浓度的增加而增强。刺苍耳根、茎、叶水浸液对小麦和苜蓿种子萌发的抑制, 不仅表现为降低种子的最终发芽率,还表现为延长种子的萌发周期。不同构件水浸液的化感效应强度整体表现为:叶>根>茎,并且化感效应强度随水浸液浓度的增加而增强。  相似文献   

10.
通过布设种子收集器收集种子,对收集的种子以时空差异进行分组分析,探讨羽毛针禾[WTBX](Stipagrostis pennata)[WTBZ]种子散布规律以及古尔班通古特沙漠种群的种子雨特征。结果表明:① 羽毛针禾种子雨的积累密度平均达到3 766.30粒·株-1,其中饱满种子占19.56%;② 种子散布的高峰集中在6月25到7月15日,其落种量占整个种子雨的61.96%,其后种子雨密度随时间逐渐减小;③ 种子雨密度与生境之间均不存在显著性差异;④ 种子雨总量与其年龄之间存在显著性差异;⑤ 种子雨的前扩散过程中种子集中降落在背风方向4 m范围和株丛周围1 m内。古尔班通古特沙漠南缘种子雨虽质量不高,但密度大,对种群的自然更新具有一定的意义。  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.
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   

13.
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   

14.
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   

15.
The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.  相似文献   

16.
Plant Viruses Transmitted by Whiteflies   总被引:18,自引:0,他引:18  
One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.  相似文献   

17.
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   

18.
《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   

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.
A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVYN strain and six to the PVYO strain. No PVYC was found. Two other isolates reacted serologically like PVYO, but were unable to elicit a hypersensitive response from the Nytbr gene and probably represent the PVYZ group. At the molecular level, these two isolates showed a combination of both PVYO and PVYN and could be recombinants of these strains. Another isolate reacted serologically like PVYO, but induced vein necrosis in tobacco, like PVYN-Wilga. Some PVYN isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVYNTN group. The PVYNTN, PVYN-Wilga and PVYZ groups probably represent pathotypes within strains PVYN and PVYO, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.  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