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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research » Research » Research Project #433817

Research Project: Genetic Improvement of Oyster Stocks for the Pacific Northwest

Location: Forage Seed and Cereal Research

Project Number: 2072-31000-005-00-D
Project Type: In-House Appropriated

Start Date: Oct 31, 2017
End Date: Oct 30, 2019

Objective:
The overall goal of this project is to improve stocks of Pacific oysters with desirable performance traits for U.S. West Coast hatchery and farm production under increasingly difficult environmental conditions of ocean acidification and the threat of the introduction of new, highly pathogenic variants of the oyster herpes virus (OsHv-1 µVar). Objective 1: Determine the effects of selective breeding in Pacific oysters for improved larval performance in acidified seawater and resistance to oyster herpes virus (OsHV-1). Subobjective 1A: Improve performance of oyster larvae in hatcheries exposed to ocean acidification (OA). Subobjective 1B: Improve resistance of Pacific NW oyster stocks to microvariants of the oyster herpes virus OsHv1.

Approach:
Utilize quantitative and molecular genetics techniques to improve the performance of Pacific oysters by 1) including larval traits (growth and setting success) in the selection index of the Molluscan Broodstock Program (MBP), and 2) including individual pedigreed oysters in the breeding program that are selected for high larval growth rates and settlement under potentially adverse commercial hatchery conditions. Collaborate with researchers in France and the Universities of Washington and Maryland to screen selected U.S. West Coast oyster stocks for resistance to new microvariants of the oyster herpes virus (OsHv-1 µVar) that have decimated Pacific oyster farms abroad. Estimate heritabilities of MBP families for resistance to OsHv-1 based on lab exposure experiments and use this information to develop effective breeding strategies to produce OsHv-1 resistant stocks of Pacific oysters for U.S. west coast farms. Objective 1: Determine the effects of selective breeding in Pacific oysters for improved larval performance in acidified seawater and resistance to oyster herpes virus (OsHV-1). Subobjective 1A: Improve performance of oyster larvae in hatcheries exposed to ocean acidification (OA). Research Goal: Implement breeding strategies to improve the survival and growth of Pacific oyster larvae in hatcheries that are dependent on sources of acidified seawater. Experimental Design: MBP stocks will be selected for improved larval performance in lab and commercial hatchery conditions. Unselected control populations will be maintained to assess the genetic improvement. Three changes to current MBP practices need to be implemented to meet these objectives: a) include performance traits for larval (hatchery) growth and settlement success in a modified MBP selection index to identify families with high breeding values (BLUPs) for both hatchery and on-farm traits. b) include individual pedigreed oysters as broodstock in the production of MBP’s cohorts that are selected from mixed families for high larval growth and settlement success under commercial hatchery conditions, as well as high growth rates at farm test sites. c) include randomly mated controls in MBP cohorts to determine the response to selection from one generation to the next. Subobjective 1B: Improve resistance of Pacific Northwest oyster stocks to microvariants of the oyster herpes virus OsHv1. Research Goal: Prepare the U.S. West Coast oyster industry for a possible accidental introduction of a microvariant of OsHV-1 µVar by developing resistant oyster stocks. Experimental Design: a) In laboratory trials, determine the potential for selection for resistance to OsHV-1 µVar infection and compare results with exposure to the Tomales Bay OsHV-1 strain. b) Formulate optimal breeding strategies to develop OsHV-1 and OsHV-1 µVar resistant broodstock.