This project focussed on increasing genetic resistance of Select Oyster Company (SOCo) breeding program Sydney rock oyster (Saccostrea glomerata, SRO) families to QX disease and winter mortality (WM) disease. NSW DPI has worked collaboratively with SOCo to develop a SRO family-based breeding program (BP) to replace the mass selection program used to develop fast growth and disease resistance since 1991. Family-based breeding has a number of distinct advantages over mass selection including; increased genetic gains, ability to select for disease resistance under biosecure conditions, improved selection methods for multiple traits, better estimates of genetic gains and trends as well as control over inbreeding. Annual family breeding runs commenced in 2014 to establish the SOCo breeding program. An FRDC project (2015-230) provided genetic expertise to establish and refine breeding methodology for a family-based breeding program.
The next step was greater understanding of the genetic parameters for QX and WM disease and how these related to other traits under selection, growth and meat condition. Genetic progress could be achieved by increasing the numbers of families available for selection, improved understanding of the genetic architecture of traits and reducing the length of breeding cycles for disease resistance. NSW DPI, SOCo, genetic specialists at CSIRO and oyster researchers at Macquarie University developed a multidisciplinary research program to deliver genetic progress for the SOCo breeding program.