西藏血蜱种群动态及其分子系统学研究

发布时间：2018-04-13 05:51

  本文选题：西藏血蜱 + 生活史　； 参考：《河北师范大学》2016年博士论文

【摘要】：西藏血蜱Haemaphysalis tibetensis仅分布在西藏自治区和甘肃省,是青藏高原地区重要的地方性病原菌媒介,而对其研究报道甚少,特别是关于其种群动态、生活史以及分子系统学方面的研究尚属空白。本文于2014年3月~2015年3月,以西藏拉萨市当雄县为研究地点,在野外可控自然环境下对西藏血蜱的生活史进行了研究。结果表明,在野外可控样方内以家兔为西藏血蜱宿主,其完成一个生活史需要177.8天(范围为129~202天)。在自然光照与气候条件下,西藏血蜱雌蜱的吸血期7.7天,产卵前期和产卵期的天数分别是9.4天和28.2天。若蜱的蜕皮前期在整个生活史中持续时间最长为52.7天。饱血雌蜱与饥饿雌蜱的体重比是58.20,且饱血体重与产卵量呈明显的正相关(r=0.8273,P0.05),雌蜱生殖效率指数与生殖适合度指数分别是5.1和4.7。对野外条件下寄生期和非寄生期西藏血蜱的季节动态进行为期两年的调查(2014年3月~2016年2月),每周采用布旗法在草地及灌丛中收集饥饿的西藏血蜱,从标记的羊体上收集寄生蜱,2014年5月至9月间每周用鼠笼诱捕高原鼠兔,检查并采集其体表寄生的幼蜱和若蜱。结果显示,西藏血蜱主要分布于草地,羊是饥饿成蜱和若蜱的主要宿主,主要寄生部位是羊耳和羊面部,高原鼠兔是幼蜱的主要宿主。野外条件下西藏血蜱一年能够完成一个生活史,并出现世代重叠现象。成蜱主要在3月~7月活动,4月中旬出现高峰;若蜱出现于3月至8月,并于7月上旬出现活动高峰,幼蜱在4月下旬到9月下旬活动,在5月下旬达到活动高峰。采用PCR方法从西藏血蜱基因组中扩增16S rDNA、COⅠ、COⅡ、12S rDNA和ITS-2测序后进行同源性分析,用MEGA7.0软件构建系统发生树并进行系统进化分析。结果显示,西藏血蜱16S rDNA、COⅠ、COⅡ、12S rDNA和ITS-2基因序列长度分别是436 bp、709 bp、249 bp、386 bp、1991 bp,转换与颠换比值分别为1.458、1.841、1.077、1.587和3.077。仅有16S rDNA和COⅠ基因序列未出现插入与缺失,ITS-2基因的G+C含量高于A+T含量,其余4个基因A+T含量较高,分别是75.2%、67.1%、69%和78.7%。分别以16S rDNA、COⅠ、COⅡ、12S rDNA和ITS-2基因以邻接法(NJ)和最大似然法(ML)构建西藏血蜱系统发生树,同一基因的两个系统发生树拓扑结构类似。16SrDNA、COⅡ和ITS-2基因构建的系统发生树均显示西藏血蜱与青海血蜱、大刺血蜱等聚类但亲缘关系较远,而在COⅠ基因中,该蜱形成独立的进化分支,未能与其他血蜱聚类,显示在血蜱属中西藏血蜱进化关系相对独立,与其他蜱种亲缘关系较远。
[Abstract]:Haemaphysalis tibetensis of Haemaphysalis Tibet is only distributed in Tibet Autonomous region and Gansu Province. It is an important local pathogen vector in Qinghai-Tibet Plateau, but there are few reports on it, especially on its population dynamics.The study of life history and molecular systematics is still blank.From March 2014 to March 2015, the life history of Haemaphysalis Tibetan was studied in a controlled natural environment in Dangxiong County, Lhasa City, Tibet.The results showed that if rabbits were used as hosts of Haemaphysalis Tibetan in the field, it would take 177.8 days to complete a life cycle (range of 129 ~ 202 days).Under natural light and climatic conditions, the days of blood absorption, pre-oviposition and oviposition were 9.4 days and 28.2 days, respectively.The maximum duration of Prophase molting in the whole life cycle is 52.7 days.The body weight ratio of female and hungry female was 58.20, and there was a significant positive correlation between the full blood weight and egg laying quantity. The reproductive efficiency index and reproductive fitness index of female tick were 5.1 and 4.7, respectively.The seasonal dynamics of Haemaphysalis Tibetan during parasitic and non-parasitic periods in wild conditions were investigated for two years (March 2014 to February 2016), and the hungry Haemaphysalis Tibetan Haemaphysalis was collected from grassland and shrub by flag spreading method weekly from March 2014 to February 2016.The parasitic ticks were collected from the labeled sheep body. From May to September 2014, the plateau pika was trapsed with a cage every week to check and collect the parasitic juvenile ticks and Icarpyrifos on the body surface.The results showed that Haemaphysalis Tibetan mainly distributed in grassland. Sheep were the main hosts of adult and Isopyrifos, the main parasitic sites were sheep ear and sheep face, and the plateau rabbit was the main host of juvenile ticks.Under field conditions, Haemaphysalis Xizang can complete a life cycle a year, and there is overlapping of generations.The activities of adult ticks mainly occurred from March to July and peaked in mid-April. If the activities of adult ticks occurred from March to August and in the first ten days of July, the activities of juvenile ticks reached the peak in late April to late September and reached the peak in late May.PCR method was used to amplify 16s rDNA CO 鈪，

本文编号：1743203