Research On Heat-tolerance Traits Of Paralichthys Olivaceus Second Generation Families

15families of Paralichthys olivaceus were constructed in2007, out of which340individuals were randomly selected as parent group. Non-sibship individuals werescreened out via unbalanced nested design, and then used to construct10patrilinealhalf-sib families and47matrilineal full-sib families by artificial fertilization.7families were randomly selected out of the second generation families. The families’growth condition were monitored and compared under high temperature stress andcontrol group were set to natural temperature. The result showed that the controlgroup’s average weight growth was38.358g, while the high temperature group’saverage weight growth was21.158g. The results are consistent with former studies.7patrilineal half-sib families and30matrilineal full-sib families were selectedout of the second generation families. Then selected30individuals out of eachselected family, weighed, marked with fluorescence marker and mix-cultured in28℃then remeasured their weight after40days culture.40-days-cultured weight andprimary weight’s regression equation were constructed. The result was:Y=2.433X+5.539, T-test (P<0.05). Pearson Correlation Score is0.899(P<0.01),meaning they are related.After emending the average weight grow of every families using regression,No.77、15、21、23、34、35、36and45families showed a faster growth in weight.The heritability of high-temperature-stress families were valued and their heritabilitywere between0.15to0.38. The T-test result showed that the full-sib families’heritability were significant and the half-sib families’ heritability were credible. Theresult also showed a major sign of maternal effect, and a larger sample amount isessential for further studies.Acute temperature lethal experiment and chronical temperature lethal experiment were conducted using individuals from the second generation families as materials.The result showed that, in acute temperature lethal experiment, individuals all died at58h, meaning no significant difference; which in chronical temperature lethalexperiment, all the individuals showed significant heat-tolerance and there werecontinuity in their death. Few individuals even significant differences (P<0.01) in theheat-tolerance trait among all the tested families. The testing temperature is vital inheat-tolerant Paralichthys olivaceus screening process, and setting lethal temperatureto31.2℃can test the heat-tolerant trait most effectively. Family No.2、11、19、36were selected as heat-tolerant families for further studies.A relativity analysis was conducted between Paralichthys olivaceus’ performancein acute/chronic temperature lethal experiments and their weight growth in hightemperature stress. The result showed a significant relativity between hightemperature stress weight growth and chronic temperature lethal experiment, thePearson Correlation Score was0.627, suggesting these two features may share acorresponding regulating mechanism under high temperature stress.