01whole.pdf (944.34 kB)
Download file

Introgression between wild and selectively-bred Sydney rock oysters (Saccostrea glomerata)

Download (944.34 kB)
thesis
posted on 28.03.2022, 19:21 by Jessica Ann Thompson
Oysters provide vital ecosystem services for coastal ecosystems worldwide. Sydney rock oysters (Saccostrea glomerata) are among the most important native Australian oysters. In 1990, a selective breeding program for faster growth rates was implemented for S. glomerata. This has since expanded to include breeding for resistance to winter mortality and QX disease. Selectively-bred oysters are currently farmed in estuaries containing wild oyster populations, providing the opportunity for interbreeding that could alter the genetic variability and structure of the wild populations. Here, we use next-generation genotype by-sequencing to investigate the genetic structures of wild populations and the selectively bred B2 line of S. glomerata. These data are used to test for genetic introgression between the populations at two sites in the Georges River, an estuary in Sydney where selectively bred oysters have been farmed since 1990. Strong genetic partitioning was identified between wild and selectively-bred populations and there was no evidence of sustained gene flow in the form of introgression. Contrary to our expectations, we found significantly higher levels of genetic diversity and heterozygosity in the selectively-bred population than the wild population. These results potentially reflect the impact of population bottlenecks and are relevant to the resilience of this species to environmental change.

History

Notes

Bibliography: pages 25-31 Thesis by publication.

Awarding Institution

Macquarie University

Degree Type

Thesis MRes

Degree

MRes, Macquarie University, Faculty of Science and Engineering, Department of Biological Sciences

Department, Centre or School

Department of Biological Sciences

Year of Award

2015

Principal Supervisor

David A. (David Andrew) Raftos

Additional Supervisor 1

Adam Stow

Rights

Copyright Jessica Ann Thompson 2015. Copyright disclaimer: http://www.copyright.mq.edu.au

Language

English

Jurisdiction

New South Wales

Extent

1 online resource (37 pages) 1 colour map

Former Identifiers

mq:46921 http://hdl.handle.net/1959.14/1088515