Ploidy diversity provides valuable scientific information, thus making the detection technique of ploidy important. However, traditional methods of cytological observation and flow cytometry are either laborious or expensive. We here report a simple and rapid, effective and economical quantitative PCR (qPCR) approach to determine the ploidy of a parasitoid species Trichogramma dendrolimi Matsumura, an economically important biocontrol agent. We applied a mitochondrial gene cytochrome oxidase (COI) and a nuclear gene forkhead to evaluate the mitochondrial number per nuclear copy in a thelytokous Wolbachia-infected strain of T. dendrolimi and its bisexual uninfected counterparts. The 2^−ΔCq values calculated from C_q values which resulted from qPCR experiments were significantly larger in haploid males than that in diploid females. Haploid males possessed about 2.69 times mitochondrial number per nuclear copy as diploid females. Not a single significant difference was found between diploid females from thelytokous and bisexual strains. Based on the differences in relative mitochondrial content, we were allowed to distinguish between haploid males and diploid females. Moreover, the number of mitochondria significantly decreased with higher ploidy level but was not affected by Wolbachia-infection. Our study supplied an available tool to investigate the ploidy diversity in sex determination of T. dendrolimi and thelytokous manipulation of Wolbachia, which is the crucial step to further study their underlying mechanisms. This will in turn contribute to the biocontrol efficiency by enhancing the female production and hence the parasitism rate.

倍性多样性提供了有价值的科学信息，因此使倍性检测技术变得重要。然而，传统的细胞学观察和流式细胞术方法既费力又昂贵。我们在这里报告了一种简单，快速，有效和经济的定量PCR（qPCR）方法，用于确定一种具有寄生性的物种Trichogramma dendrolimi Matsumura的倍性，这是一种经济上重要的生物防治剂。我们应用了线粒体基因细胞色素氧化酶（COI）和核基因叉头，评估了被Wolbachia感染的T. tolytokous感染菌株中每核拷贝的线粒体数。Dendrolimi及其双性恋未感染者。2- ^ΔCq通过qPCR实验得出的C _q值计算得出的单倍体雄性个体值明显高于二倍体雌性个体。与二倍体雌性相比，单倍体雄性每核拷贝具有约2.69倍的线粒体数。在lytokous和双性恋品系的二倍体雌性之间未发现单一显着差异。根据相对线粒体含量的差异，我们可以区分单倍体雄性和二倍体雌性。此外，线粒体数目随着倍性水平的增加而显着减少，但不受沃尔巴氏菌感染的影响。我们的研究提供了一个可用的工具，以调查性别的T决定倍性。树枝状和Wolbachia的lytokous操纵，这是进一步研究其潜在机制的关键步骤。反过来，这将通过提高雌性产量并因此提高寄生率来提高生物防治效率。