马氏珠母贝经济性状对体重决定效应分析

Analysis of Determination Effects of Economic Traits on Body Weight of Pinctada martensii(Dunker)

采用通径分析方法研究了不同养殖区马氏珠母贝各分性状对体重的决定效应。结果表明:流沙养殖群体分性状壳长、壳高、壳宽、铰合线长、软体部重和闭壳肌重与体重间呈正相关(P<0.01),对体重的直接决定效应分别为0.091、0.072、0.029、0.002、0.089和0.001,间接决定效应分别为0.319、0.284、0.183、0.03、0.304和0.004,总决定效应分别为0.41、0.356、0.212、0.032、0.393和0.005;6个经济性状与体重间的关系在抽样断面上可用线性回归模型拟合,复相关系数达0.939(P<0.01)。6个性状3类决定效应按大小排列均为壳长>软体部重>壳宽>壳高>铰合线长>闭壳肌重。迈陈养殖群体作为验证群体,各效应值与前者有差异,但3类决定效应大小排序与前者完全相同。基于决定效应大小及性状易测性,育种目标性状的选择策略为首选壳长,二选壳高,三选壳宽。研究还发现壳宽对软体部重具有最大的决定效应,提出加大壳宽选择强度以培育大型珍珠新观点。

The effect of various component traits in Pinctada martensii（Dunker） from different culture areas upon body weight was examined in the paper through the path analysis method. Results showed for the cultured population in Liusha that the component traits such as shelllength, shell height, shell width, hinge length, tissue weight and adductor weight were positively related to body weight（P〈0.01）, direct effects of determination of above component traits on body weight were 0.091,0.072,0.029,0.002,0.089 and 0.001 respectively, indirect effects of determination were 0.319,0.284,0.183,0.03,0.304 and 0.004 respectively, and overall effects of determination were 0.41,0.356,0.212,0.032,0.393 and 0.005 respectively. The relationship between body weight and 6 component traits of interest could be fitted by linear regression model, with the multiple correlation at 0.939（P〈0.01）. In terms of the size of all types of determination effect for 6 component traits of interest, the sequence of shell length〉tissue weight〉shell width〉shell height〉hinge length〉adductor weight was obtained. The trait effects of the Maichen cultured population ,which was served as the validation in the study, were different from those of Liusha population, butthe order of 3 types of determination effects were entirely the same as the former. Allowing for the size of determination effect and difficulty in trait measuring, the first selection for the breeding target traits was shell length, shell height was second and then shell width. Shell width and tissue weight had the greatest effect on body weight, the new viewpoint of heightening up selection intensity for the trait shell width so as to produce large pearl was thereby proposed. Results derived in the paper can be served as the scientific foundation on which to carry out the formulation of breeding target traits of Pinctada martensii（Dunker）.