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141.
142.
芽胞杆菌种类脂肪酸鉴定与分子鉴定方法的比较 总被引:1,自引:0,他引:1
基于ITS序列和脂肪酸鉴定方法对从土壤中分离得到的16株芽胞杆菌进行分类研究,与分子鉴定结果相比,脂肪酸种的鉴定准确率可达到99%以上。通过生物软件SPSS和Mega分别对16株菌进行聚类分析,结果表明,脂肪酸比ITS更适合于芽胞杆菌的分类研究,根据脂肪酸成分可以将16株芽胞杆菌准确聚在一起,而ITS则不能。芽胞杆菌特征性脂肪酸为15∶0ANTEISO和15∶0ISO,但不同种芽胞杆菌的此类脂肪酸含量不同。对芽胞杆菌3大类菌群主要特征性脂肪酸的含量比例(15∶0ISO/15∶0ANTEISO)进行了分析,其中比较特殊的为蜡状芽胞杆菌类群,蜡状芽胞杆菌主要脂肪酸为15∶0ISO,其次为13∶0ISO,而15∶0ANTEISO的含量很低,而且不是主要类型,15∶0ISO/15∶0ANTEISO的比值约为5.6~7.9。简单芽胞杆菌群主要脂肪酸为15∶0ANTEISO和15∶0ISO,15∶0ISO/15∶0ANTEISO比值约为1/6。巨大芽胞杆菌类群主要脂肪酸15∶0ISO和15∶0ANTEISO含量相近,其余脂肪酸远远低于这2种主要脂肪酸。巨大芽胞杆菌的15∶0ISO/15∶0ANTEISO的比值约为4/5~5/4,菌株FJAT-4500为短小芽胞杆菌,其15∶0ISO/15∶0ANTEISO比值约为2。短小芽胞杆菌和巨大芽胞杆菌归为一类是因为其脂肪酸类型相近,但含量并不同。枯草芽胞杆菌群主要脂肪酸15∶0ISO的含量小于15∶0ANTEISO,15∶0ISO/15∶0ANTEISO的比值为1/3~2/3。 相似文献
143.
细河河岸带植物多样性研究 总被引:1,自引:0,他引:1
以野外样方调查数据为基础,详细调查了辽宁省太子河主要支流细河河岸带植物群落的组成、种类和外貌,应用重要值计算了细河河岸带植物丰富度指数、多样性指数、均匀度指数、优势度指数,并分析了其物种的多样性差异,从而为细河河岸带的生态修复提供理论和技术依据。结果表明:细河河岸带植物群落27个植物样方中共有23科60属99种,物种组成以菊科、蓼科、禾本科、莎草科、蔷薇科、唇形科植物为主,植物种类以荩草、藨草、中华结缕草、野稗、三叶草、老芒麦、问荆.、野艾蒿、桃叶蓼、狗尾草等为主。细河河岸带植物物种结构简单,物种组成较少。植物物种多样性水平较低,从多样性指数的数量特征来看,丰富度指数7.00~25.00,Pielou均匀度指数0.54~0.94,Simpson多样性指数0.56~0.92,Shannon-Wiener多样性指数1.44~2.80,Simpson优势度指数0.08~0.44。细河河岸带受到人为活动干扰,如农业生产、挖沙等人为活动干扰降低了植物多样性水平。 相似文献
144.
145.
Overdose and death of both target and non-target species are not uncommon when α–chloralose is used for animal control. Alpha–chloralose appears to depress the central nervous system by having an affect on the GABA-A receptor in a manner similar to ethanol. Recently central administration of oxytocin was shown to block ethanol-induced impairment in rodents. Our study investigates whether IM administration of oxytocin speeds avian recovery from α–chloralose and reduces mortality under simulated field conditions. We found that when injected twice with oxytocin (30 uL/kg) chickens entered α–chloralose narcosis more quickly and showed greater behavioral impairment. When fed the LD50 dose of α–chloralose, repeated injection with oxytocin produced no significant difference in mortality rate or time to death in comparison to the control group. The effects of peripheral oxytocin on female chicks were different than results found previously in cockerels given oxytocin centrally. Oxytocin is not a suitable antidote for α–chloralose overdose during animal capture in the field but instead accentuates α–chloralose narcosis, making capture more likely and efficient. 相似文献
146.
广西桉树林取代马尾松林对植物多样性的影响 总被引:2,自引:0,他引:2
对广西钦州市马尾松林和巨尾桉人工林的植物多样性开展研究,旨在阐明桉树林取代马尾松林对植物多样性和植物功能群的影响,促进对桉树人工林的科学认知。研究表明,采伐马尾松林种植桉树后10年,在1 800 m2样地内,桉树林的物种数为95~98种(木本植物50种,藤本17~19种,草本24~28种),而马尾松林为63~88种(木本植物32~48种,藤本13~24种,草本16种),两类林分的木本、藤本和总物种数差异不显著(P为0.237~0.937),而草本植物差异显著(P=0.038),表明桉树林取代马尾松林将显著增加草本植物的物种丰富度。桉树林取代马尾松林对铁芒萁有显著的负效应,重要值减少50%(P=0.077),而对五节芒(P=0.057)和东方乌毛蕨(P=0.079)有显著的正效应,重要值提高0.85~3.76倍。桉树林和马尾松林木本植物的Shannon Wiener指数(H′)、Simpson指数(D)和均匀度指数(Jsw)差异不显著(P为0.299~0.957),而草本植物的H′、D和Jsw差异极显著(P≤0.002)。桉树林取代马尾松林对群落的物种多样性和功能群具有显著的影响,然而,桉树人工林建立过程中采取的采伐、炼山、整地、施肥等措施是导致群落物种多样性和功能群变化的主要原因。 相似文献
147.
对浙西南柑橘园杂草种群调查结果表明,柑橘园共有杂草80种,隶属27科。杂草数量最多的为禾本科,有20种,占杂草总数的25.0%;其次是菊科,有11种,占杂草总数的13.8%。主要杂草集中分布的月份为7、8,9、10、115个月。冬、春季柑橘园杂草优势种为:早熟禾、猪殃殃、看麦娘、牛繁缕、婆婆纳。夏、秋季杂草优势种为:马唐、铁苋幕、牛筋草、小飞蓬、旱稗。 相似文献
148.
Efficiency of reduced primer selectivity and bulked DNA analysis for the rapid detection of AFLP† polymorphisms in a range of crop species 总被引:2,自引:0,他引:2
Rob van Treuren 《Euphytica》2001,117(1):27-37
Two approaches to optimise AFLP fingerprinting forthe rapid detection of genetic polymorphisms, i.e.reduced primer selectivity and bulked DNA analysiswere examined. The efficiency of reduced primerselectivity to increase the detection frequency ofgenetic polymorphisms and to obtain more informativefingerprinting profiles was tested in six differentcrops. The number of selective nucleotides was reducedto six in onion, to five in barley, potato, lettuceand cabbage, and to four in flax. This allowed therapid identification of several primer pairs that wereable to discriminate between closely relatedgermplasm. Reproducibility tests on replicate DNAsamples indicated no major negative effects on thereliability of the fingerprinting profiles due to theuse of less selective primers, although for onionpurified DNA was needed to avoid irreproducibleresults. In barley, flax and onion, a less thanfourfold increase in the number of fragments wasobserved when primer pairs were reduced by oneselective nucleotide. This result was attributed todifferent tolerance levels for amplificationmismatches between primer pairs of differentselectivity.The efficiency of bulked DNA analysis to detectgenetic polymorphisms was investigated in differentmixtures of two barley DNA samples. AFLP's of varyingintensity could still be recovered when the two DNA'swere mixed in a 1:1 ratio. However, the frequency ofrecovered bands quickly dropped when in the mixturesthe presence of the DNA carrying the fragments wasdecreased below 50%.The usefulness of the two approaches is discussed inrelation to various aspects of genetic resourcesmanagement. 相似文献
149.
《Integrative zoology》2017,12(3):186-197
The involvement of communities in ecological studies has been shown to augment conservation efforts, especially for cryptic species. However, there is a lack of studies addressing the utility of incidental sighting records from community members in gaining knowledge on habitat preferences and distribution of suitable habitat for these organisms. This study compares preferences of the Lumholtz's tree kangaroo (Dendrolagus lumholtzi ; LTK), a cryptic rainforest folivore in northeastern Australia, for various habitat and climatic variables derived from data collected during scientific projects to those derived from incidental sighting records using ArcGIS and Maxent. Incidental sighting records suggest that the species uses a wider range of altitudes, annual rainfalls, annual mean temperatures and vegetation types than predicted by scientific studies. Incidental records also show that the species can persist in areas of lower rainfall during the wettest month and lower minimum temperature during the coldest month. Both data place the species within a comparable range of rainfalls during the driest month, maximum temperatures of the warmest month and soil types. When using identified preferences to assess the extent and distribution of suitable habitat, incidental records predicted more areas of suitable habitat than scientific records with an overlap of up to 91% between them. The present study proves that incidental sighting records can be a valuable part of the study of cryptic species and should be considered complementarily alongside scientific studies to obtain comprehensive ecological information of a species that can assist in its conservation. 相似文献
150.