蛤蜊岗不同贝龄四角蛤蜊数量性状的通径分析

Path analysis of quantitative characters for Mactra veneriformis with different ages in Geligang

关键词:  四角蛤蜊  形态性状  通径分析  相关分析

Key words:  Mactra veneriformis  Morphological character  Path analysis  Correlation analysis

摘要:

为研究蛤蜊岗不同贝龄四角蛤蜊(Mactra veneriformis)形态性状与质量性状之间的相关性，采用相关分析、通径分析和多元回归分析等方法，对1~3龄四角蛤蜊的壳长(SL)、壳宽(SW)、壳高(SH)、活体湿重(BW)和软组织湿重(RW)等参数进行分析，建立形态性状与质量性状之间的回归方程。结果显示，不同生长阶段四角蛤蜊形态性状对质量性状的贡献存在极显著差异(P<0.01)。与1~3龄四角蛤蜊活体湿重最相关的形态性状均为壳宽。对软组织湿重影响最大的形态性状，在1龄贝为壳宽，在2龄和3龄贝为壳长。壳高对2龄四角蛤蜊活体湿重和软组织湿重的直接通径系数均未达到显著水平(P>0.05)。以活体湿重为目标性状时，1~3龄贝均应以壳宽为主要选择性状，并以壳长作为辅助选择性状；以软组织湿重为目标性状时，1龄贝应以壳宽为主要选择性状，同时辅以壳长；2龄和3龄贝均应以壳长为主要选择性状，并分别以壳宽和壳高作为2龄贝和3龄贝的辅助选择性状。研究结果可为蛤蜊岗四角蛤蜊良种选育提供基础数据。

Abstract:

Mactra veneriformis is a common economic benthic shellfish with high nutritional value and is widely distributed in the Shandong and Liaoning provinces. Geligang is located in the northern part of Liaodong Bay. It is formed by the water impact of Shuangtaizi and Liaohe River. It has an area of approximately 10 000 hm2 with a fertile substrate. It is an important habitat of beach shellfish, such as M. veneriformis. Studies on the influencing factors of wild population quality traits and their correlation with morphological traits are helpful for developing genetic breeding of marine shellfish. To analyze the effects of morphological traits on quality traits of M. veneriformis at different ages in Geligang, the shell length (SL), shell width (SW), shell height (SH), body weight (BW), and soft tissue wet weight (RW) of 1–3 years old M. veneriformis were analyzed using correlation analysis, path analysis, and multiple regression analysis. The M. veneriformis used in the experiment was obtained from the Geliang in Liaodong Bay in September 2022. A total of 80 1-year-old, 104 2-year-old, and 168 3-year-old M. veneriformis were obtained. The results showed that the morphological traits of M. veneriformis at different growth stages had different contributions to quality traits, and there were significant differences (P<0.01). SW had the greatest direct effect on the BW of 1–3 year-old M. veneriformis, but had different effects on the RW; SW had the greatest direct effect on 1-year-old M. veneriformis; and SL had the greatest effect on 2- and 3-year-old M. veneriformis. The direct path coefficient of SH to the BW and RW of 2-year-old M. veneriformis did not reach significant level (P>0.05) and was eliminated. The optimal regression equation of quantitative traits to qualitative traits of 1–3 year-old M. veneriformis was established. The results showed that when BW was the target trait, SW was the main selection trait and SL was the auxiliary selection trait for 1–3 year-old M. veneriformis. When RW was the target trait, SW should be the main selection trait for 1-year-old M. veneriformis, supplemented by SL. The SL should be the main selection trait for both 2- and 3-year-old M. veneriformis, but the SW was the auxiliary selection trait for 2-year-old M. veneriformis, while the SH was for 3-year-old M. veneriformis. In this study, correlation analysis, path analysis, and multiple regression analysis were performed on the morphological traits and quality traits of 1–3 years old M. veneriformis to determine the key morphological traits affecting the quality traits of M. veneriformis at different ages. In this study, the R2 values of the morphological traits of 1- and 2-year-old M. veneriformis (0.898 and 0.859, respectively) were greater than 0.850, indicating that the main factors affecting the body weight of living M. veneriformis were found. However, the R2 value of the morphological traits of 3-year-old M. veneriformis (0.815) was below 0.850, indicating that there may be other influencing traits in addition to the traits analyzed in this study. The reason may be that with the growth of M. veneriformis, the thickness of the shell and the effect on the weight of the living body gradually increase. In this study, the R2 values of morphological traits of 1–3 years old M. veneriformis (0.738, 0.648, and 0.538, respectively) on the wet weight of soft tissue were all below 0.850, indicating that there were other key factors affecting the wet weight of soft tissue. The age of sexual maturity of the M. veneriformis is at 1 year. The development of the gonad in the soft part may be closely related to the size of the wet weight of the soft tissue. The sampling period is mainly in the proliferation to depletion period of the gonad development of M. veneriformis. The gonad development is simultaneously affected by the environment. These results can provide reference for breeding M. veneriformis and the selection of parent shellfish.