玉米螟赤眼蜂种群特异分子标记构建及其应用

赤眼蜂是我国乃至世界范围内应用最广的卵寄生蜂,其中玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen是我国玉米种植区重要的天敌昆虫,但其不同的地理种群在生物防治效果上存在较大差异。为了有效利用玉米螟赤眼蜂的优势种群,有必要对其进行准确的鉴别。然而,采用传统形态学方法对同一种赤眼蜂的不同种群进行鉴别是非常困难的。本研究首先采用随机扩增多态性DNA(RAPD)标记对采自我国北京农科院、山东日照和山西太原的3个玉米螟赤眼蜂种群,进行了遗传差异分析,然后筛选了种群特异性位点,并通过克隆测序和引物设计构建了种群特异性分子标记,即序列特征性扩增区域(SCAR)标记。最后,利用SCAR标记对混合蜂群竞争试验结果进行了分子检测。该研究方法有助于玉米螟赤眼蜂优势种群的筛选,对于赤眼蜂的有效利用具有重要的意义。

Development and applications of population-specific markers of Trichogramma ostriniae in China

Trichogramma spp. （Hymenoptera：Trichogrammatidae） are the most-widely used egg parasitoids in China and the world. T. ostriniae Pang et Chen is an important biocontrol agent in corn crops in our country, but different T. ostriniae populations display different biocontrol efficacy. In order to make full use of the most beneficial populations, it is essential to be able to precisely discriminate between populations. However, it can be extremely difficult to distinguish different populations of the same Trichogramma species by using morphological methods. In this study, random amplified polymorphic DNA markers were used to analyze genetic variations between T. ostriniae populations collected from Beijing, Shandong and Shanxi, and population-specific loci were then located. From sequencing of population-specific loci, population-specific markers were successfully developed which were subsequently employed to determine the most effective biocontrol populations in mixed population testing. This method is helpful in screening for the most beneficial Trichogramma populations, and therefore plays a significant role in the application of Trichogramma spp. to biocontrol.