Absence of complementary sex determination in Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae)
- Published
- Accepted
- Subject Areas
- Agricultural Science, Entomology
- Keywords
- maternal effect genomic imprinting sex determination, multilocus complementary sex determination, diploid male, inbreeding, biocontrol, mass rearing
- Copyright
- © 2019 Liu et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2019. Absence of complementary sex determination in Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) PeerJ Preprints 7:e27871v1 https://doi.org/10.7287/peerj.preprints.27871v1
Abstract
Over 60 species in Hymenoptera have been reported to possess a complementary sex determination (CSD) system. Under CSD, sex is determined by allelic complementation at one or several sex loci. But this mechanism is still uninvestigated in parasitoid wasp Trichogramma dendrolimi, one of the most important biocontrol agents widely used against Lepidopteran pests. We tested CSD in this species by conducting ten consecutive generations of inbreeding, to monitor both direct evidence (diploid male production) and indirect evidence (brood size, sex ratio, mortality). In total 475 males detected from this inbreeding regime, only one was determined as diploidy. The observed proportions of diploid male offspring significantly differed from expected values under CSD model involving up to ten independent loci, allowing us to safely reject CSD in T. dendrolimi. Meanwhile, the possibility of unviable diploid males was excluded by the absence of significant differences in brood size, offspring sex ratio and offspring mortality among different generations. Our study of sex determination in T. dendrolimi provides useful information for the mass rearing conditions in a biofactory and the quality improvement of this biocontrol agent. It also brings necessary background to further study of the sex determination in Trichogramma.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Detection of Male Ploidy
It shows the results of ploidy detection of male wasps (primary indicator) in "Detection of Diploid Males" part by a qPCR method.
Inbreeding&Outcross
It shows the results of multiple generations of consecutive inbreeding and outcross (control), whereby brood size, offspring sex ratio and offspring mortality (secondary indicators) can be calculated and analyzed.