Evaluation of the progeny of second-generation Sydney rock oyster Saccostrea glomerata (Gould, 1850) breeding lines for resistance to QX disease Marteilia sydneyi

Abstract

The progeny of second-generation Sydney rock oyster Saccostrea glomerata (Gould, 1850) breeding lines were tested for resistance to QX disease Marteilia sydneyi against a non-selected control. Mortality was reduced from 85.7±1.5% for the controls to 63.5±1.2% for the most improved breeding line. This is a reduction in mortality of 22% after only two generations of selection. These partially QX disease-resistant oysters in which M. sydneyi was found were also 21% heavier than controls. Selection for resistance to M. sydneyi is feasible and may be improved through further selection.