The SRO industry has the potential to exploit new export initiatives and increase production. Any resurgence in the industry will depend on SOCo’s ability to manage the development and supply of selectively bred oysters. FRDC has fostered this process by supporting breeding programs and hatchery research, whilst encouraging industry management of technology. The Benzie Report, Oyster Research Advisory Committee (ORAC) R&D Strategic Plan and the Action Plan developed at the FRDC-funded QX workshop in June 2005 have all indicated that effective management strategies for the SRO industry must be underpinned by; 1) the continued development of oyster husbandry techniques to secure QX resistant breeding lines, and, 2) the identification of genes associated with QX disease resistance that can be used for marker-assisted selection. These complementary research goals represent a critical step in “QX proofing” NSW estuaries against ongoing and catastrophic QX disease outbreaks. Continued research may also allow farming to be re-established in areas abandoned because of QX disease. Integration of genetic markers and single pair mating into the hatchery-based breeding program will increase the efficiency of selection, and decrease the number of generations required to establish true breeding resistant lines. Without marker assisted selection, the breeding program may not reach its full potential in time to prevent further losses.
A comprehensive presentation on the SRO industry will be given during the FRDC board’s visit to Port Stephens in July 2006.
Final report
The Select Oyster Company breeding plan has been amended to include a comprehensive manual of protocols for pair mating Sydney rock oysters (4.1). The association between phenoloxidase (PO) and QX resistance has been confirmed and a sensitive test for PO genotypes has been developed so that the breeding program has a tool to genotype parents and large numbers of their progeny to assist breeding (4.2-4.8). Protocols for cryopreservation of gametes have been developed and documented as a potential strategy to reduce SOCo’s overall maintenance costs for the lines and increase genetic security (4.9). Non-chemical means of triploidy induction in SRO (temperature and pressure shock) were tested (4.10). While these techniques were not as effective as existing chemical induction techniques, they have formed the basis of ongoing research to see if efficacy can be increased. A total of 60 pair mated family lines, including 31 lines with differing PO phenotypes, have been produced and are undergoing performance assessment in the field. These families will be made available to SOCo for incorporation in the industry breeding program.
