South African Sugarcane Research Institute, 170 Flanders Drive, Mount Edgecombe 4300, South Africa.
J Invertebr Pathol. 2012 Nov;111(3):225-36. doi: 10.1016/j.jip.2012.08.010. Epub 2012 Sep 8.
Beauveria brongniartii (Saccardo) Petch fungal infections were observed on the melolonthid Hypopholis sommeri Burmeister (Coleoptera: Scarabaeidae) at two sites (Harden Heights and Canema) in the sugarcane producing area of the northern KwaZulu-Natal Midlands of South Africa. To initially identify the disease-causing fungus, 17 different fluorescently-labelled microsatellite PCR primers were used to target 78 isolates of Beauveria spp. DNA. Microsatellite data resolved two distinct clusters of Beauveria isolates which represented the Beauveria bassiana s.s. (Balsamo) Vuillemin (17 isolates) and B. brongniartii (60 isolates) species groups. These groupings were supported by two gene regions, the nuclear ribosomal Internal Transcribed Spacer (ITS) and the nuclear Bloc gene of which 23 exemplar Beauveria isolates were represented and sequenced. When microsatellite data were analysed, 26 haplotypes among 58 isolates of B. brongniartii were distinguished. Relatively low levels of genetic diversity were detected in B. brongniartii and isolates were shown to be closely related. No genetic differentiation was observed between the Harden Heights and Canema populations; they thus may be considered one, structured and fragmented population over a distance of 5.5 km. Historically high levels of gene flow from swarming H. sommeri beetles is the proposed mechanism for this observed lack of genetic differentiation between populations. Microsatellite analyses also showed that B. brongniartii conidia were being cycled from arboreal forest to subterranean sugarcane habitats and vice versa in the environment by H. sommeri life stages. This is the first record of this species of fungus infecting H. sommeri larvae and adults in South Africa.
在南非夸祖鲁-纳塔尔省北部米德尔堡地区的两个地点（哈登高地和卡内马），观察到一种名为白僵菌（Saccardo）Petch 的真菌感染了 Hypopholis sommeri Burmeister（鞘翅目：金龟子科）。为了初步确定致病真菌，使用了 17 种不同的荧光标记微卫星 PCR 引物，针对 78 个白僵菌属分离株的 DNA 进行了靶向分析。微卫星数据将白僵菌分离株分为两个不同的簇，代表了白僵菌 s.s.（Balsamo）Vuillemin（17 个分离株）和 B. brongniartii（60 个分离株）物种群。这两个分组得到了两个基因区域的支持，即核核糖体内转录间隔区（ITS）和核 Bloc 基因，其中代表并测序了 23 个白僵菌分离株。当分析微卫星数据时，在 58 个 B. brongniartii 分离株中区分出了 26 种单倍型。在 B. brongniartii 中检测到相对较低水平的遗传多样性，并且分离株之间的关系非常密切。在哈登高地和卡内马种群之间没有观察到遗传分化；因此，它们可能被视为在 5.5 公里的距离内一个结构完整但碎片化的种群。历史上，来自成群结队的 H. sommeri 甲虫的高水平基因流是造成种群间缺乏遗传分化的原因。微卫星分析还表明，B. brongniartii 分生孢子通过 H. sommeri 的生活阶段在森林和地下甘蔗栖息地之间循环，反之亦然。这是该真菌感染南非 H. sommeri 幼虫和成虫的首次记录。
