Department of Zoology and Entomology, PO Box 94, Rhodes University, Grahamstown 6140, South Africa.
J Invertebr Pathol. 2013 Mar;112(3):219-28. doi: 10.1016/j.jip.2012.12.008. Epub 2012 Dec 28.
False codling moth, Thaumatotibia leucotreta (Meyrick) is a serious pest of economic importance to the South African fruit industry. As part of sustainable efforts to control this pest, biological control options that involve the application of baculovirus-based biopesticides such as Cryptogran and Cryptex (both formulated with a South African isolate of Cryptophlebia leucotreta granulovirus, CrleGV-SA) are popularly used by farmers. In order to safeguard the integrity of these biopesticides as well as protect against any future development of resistance in the host, we conducted a study to bioprospect for additional CrleGV isolates as alternatives to existing ones. Using overcrowding as an induction method for latent infection, we recovered five new CrleGV isolates (CrleGV-SA Ado, CrleGV-SA Mbl, CrleGV-SA Cit, CrleGV-SA MixC and CrleGV-SA Nels). Single restriction endonuclease (REN) analysis of viral genomic DNA extracted from purified occlusion bodies showed that isolates differed in their DNA profiles. Partial sequencing of granulin and egt genes from the different isolates and multiple alignments of nucleotide sequences revealed the presence of single nucleotide polymorphisms (SNPs), some of which resulted in amino acid substitutions in the protein sequence. Based on these findings as well as comparisons with other documented CrleGV isolates, we propose two phylogenetic groups for CrleGV-SA isolates recovered in this study.
假苹果卷叶蛾（Thaumatotibia leucotreta）是南非水果产业中具有重要经济意义的严重害虫。作为可持续控制这一害虫的努力的一部分，农民普遍使用基于杆状病毒的生物防治选择，例如 Cryptogran 和 Cryptex（均由南非假苹果卷叶蛾颗粒体病毒 CrleGV-SA 制成）。为了保护这些生物农药的完整性并防止宿主未来产生任何抗性发展，我们进行了一项研究，以寻找额外的 CrleGV 分离物作为现有分离物的替代品。我们使用过度拥挤作为潜伏感染的诱导方法，从纯化的包埋体中回收了五个新的 CrleGV 分离物（CrleGV-SA Ado、CrleGV-SA Mbl、CrleGV-SA Cit、CrleGV-SA MixC 和 CrleGV-SA Nels）。从纯化的包埋体中提取的病毒基因组 DNA 的单限制内切酶（REN）分析表明，分离物在 DNA 图谱上存在差异。从不同分离物中提取的 granulin 和 egt 基因的部分测序以及核苷酸序列的多重比对显示存在单核苷酸多态性（SNP），其中一些导致蛋白质序列中的氨基酸替换。基于这些发现以及与其他记录的 CrleGV 分离物的比较，我们为在本研究中回收的 CrleGV-SA 分离物提出了两个系统发育群。
