假臭草丛枝病植原体昆虫媒介的传毒特性研究

Study on Transmission Characterization of Vector for Phytoplasma Associated with Praxelis Witches' Broom

假臭草目前在海南乃至整个华南地区发生严重,而假臭草丛枝病植原体在一些地区可以严重影响其生长发育,研究专一昆虫媒介对假臭草丛枝病植原体传毒的特性与机理,将有助于深入假臭草生物防治。本文用寻集法和网集法采集海南地区不同生境下单一假臭草群落中的昆虫,捕捉到具有刺吸式口器的主要昆虫有粉蚧(粉蚧科、棉粉蚧亚科、棉粉蚧属Phenacoccus spp.)和蚜虫(蚜科、缢管蚜属Rhopalosiphum spp.)2种,并通过PCR检测对假臭草丛枝病植原体媒介及其传毒特性进行了研究。结果表明:蚜虫是传播假臭草丛枝病植原体的昆虫媒介。蚜虫获毒时间阈值为5 min,传毒时间阈值为0.5 h,传毒最少数量为10头,且随着时间、数量的增加,传毒率与获毒率均增加,但传毒率比获毒率低。

Praxelis （Praxelis clematidea） weed has become highly invasive in south China in recent years. Phytoplasma of Praxelis witches＂ broom were founded in Hainan province and the diseased plants infected the phytoplasma finally failed to finish the reproductive growth. Studies on characteristics and mechanism of disease transmission of specific insect vector of praxelis weed will contribute to promoting its biocontrol. In this paper, the methods of visual search and netting were used to collect the insects in pure community at different habitats in Hainan. Thereby, two kinds of insects with sucking mouthparts, including Phenacoccus spp and Rhopalosiphum spp. , were collected. And studies were conducted to the insect vector of phytaplasma of Praxelis witches＇ s broom and its transmission characteristics. The results showed the Praxelis witches＇ s broom disease could be transmitted by the adult of Rhopalosiphum spp. It transmitted praxelis witches＇ s broom symptom diseases after a minimum acquisition-access period of 5 rain. The transmission time threshold for the disease was 0.5 h, and the numbers of aphid adults used to transmit the disease was 10. With the increase of inoculating time and the vector numbers, both the acquisition rate and transmission rate also increased, but acquisition rate was lower all the time.