Analysis of genotype-environmental interaction of turbot(Scophthalmus maximus) based on AMMI model

Abstract

Turbot(Scophthalmus maximus),a flatfish of deep water species,is a high-nutrition and economic-valued species and currently cultured widely in China.In recent years,however,serious germ plasm degeneration has come into being due to the lack of the long-term and effective broodstock management programmes,production of farmed turbot became highly unstable and total output declined gradually.Therefore,large-scale family selection programs recurring to PIT tag have been used to initiate the genetic improvement of turbot since national eleventh five-year plan by the Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Science.At present,F2 population has been finished.In order to obtain new strains(or new varieties) and the extension of fine families,it was highly important,in the process of selective breeding,to obtain fine families with universality and fine families with exclusiveness.Thus,we carried out genotype-environment interaction analysis.In this paper,ten families from turbot selective breeding F2 were dispatched in r a n d o m i z e d b l o c k d e s i g n to five farms in different locations(Liaoning,Jiangsu,Fujian,Shandong-1,Shandong-2) representing a wide variety of environmental conditions and data of body weight were collected.AMMI(Additive Main and Multiplicative Interaction) Model was used to analyze data collected.The results showed that G×E interaction for body weight was significantly different(P 0.01) and G×E effects on body weight was higher than those of families genotype.The former was equal to 1.44 times of the latter.The yield of family G5 and G8was comparatively high(844.796 g and 868.888 g) and the stability parameter of the two families was the lowest(1.154 975 and 2.668 016).Obviously,family G5 and G8 had a high and stable yield and wide adaptability and the two kinds of genotypes were beneficial to selective breeding of new variety(or new strain).Five test locations were divided into three environment groups,i.e.,Group E3,Group E5 and Group E1-E2-E4,at the same time,family G6,G10 and G2 should be dispatched to the environment Groups E3,E5,E1-E2-E4,respectively,based on Which-won-where view of the AMMI biplot(the yield of family G6,G10 and G2: 851.768 g,911.664 g and 784.764 g).The conclusion of the study can provide theoretic basis for selective breeding of new strains(or new varieties) and the extension of fine families.