日本沼虾五群体形态性状对体质量的通径分析

为筛选出影响日本沼虾体质量的主要形态性状,以便确定人工选育的理想测定指标,以太湖、鄱阳湖、白洋淀、微山湖及淀山湖的野生日本沼虾为研究对象,随机选取各群体90尾虾测定19个形态指标,采用简单相关分析和通径分析等多元回归分析方法分析各群体对体质量作用较为突出的形态性状,并进行聚类分析。通径分析结果显示,太湖群体体长、头胸甲宽、第二步足长、头胸甲高、尾扇长对体质量的通径系数达到极显著,逐步回归建立其对体质量的回归方程、回归截距及相应的回归系数分别为–9.878、0.075、0.314、0.011、0.320、0.222;鄱阳湖群体头胸甲长、尾扇长、尾节宽、头胸甲宽、头胸甲高、尾节高、体长性状对体质量的通径系数达到极显著,回归截距和相应的回归系数分别为–1.618、0.392、–0.280、0.703、0.524、–0.359、0.688、–0.061;白洋淀群体体长、头胸甲宽、第二步足长和尾扇长对体质量的通径系数达到极显著,其回归截距和相应的回归系数分别为–4.796、0.082、0.222、0.007、0.136;微山湖群体头胸甲长、腹节高、第二步足长、腹节宽对体质量的通径系数达到极显著,其回归截距和相应的回归系数分别为–7.644、0.248、0.329、0.025、0.301;淀山湖群体体长、第二步足长、头胸甲宽、尾节宽、腹节宽对体质量的通径系数达到极显著,其回归截距和相应的回归系数为–6.257、0.019、0.018、0.164、0.264、0.162。体长与头胸甲性状在不同群体中都对体质量的作用十分明显。聚类结果显示,地理位置越接近,形态上越相似。研究表明,各个地区被保留的性状与体质量的复相关系数为0.965、0.904、0.902、0.971、0.955,为影响各自群体体质量的主要自变量。

Path analysis for the correlations between morphological traits and body weight in five Macrobrachium nipponense populations

In order to determine the influence of the main morphological traits on body weight of Macrobrachium nipponense, and to screen the optimal and measurable indices for artificial breeding of M. nipponense, the correlations between morphometric attributes and body weight of M. nipponense were explored using correlation analyses, path analyses and regression analyses. Ninety individuals from each of five populations (Tai Lake, Poyang Lake, Baiyang Lake, Weishan Lake and Dianshan Lake) were randomly sampled for the measurements of their body weight and 18 morphometric attributes, including the body length, overall length, rostrum length, second pereiopod length, diatance between eyes, carapace length, carapace width, carapace height, first abdominal segment height, first abdominal segment width, abdomen length, telson length, telson width, telson height, fantail length, fantail width, number of upper frontal eminencespin and number of lower frontal eminence spin. Correlation coefficients among all variables were calculated. Path coefficients were calculated by setting the body weight as a dependent variable and other attributes as independent variables via stepwise elimination. The path coefficients showed that: (1)five morphometric attributes of the Tai Lake population (body length, carapace width, second pereiopod length, carapace height, fantail length) significantly correlated to body weight. A multiple regression equation of the five attributes was established, where the regression intercept and regression coefficients were -9.878, 0.075, 0.314, 0.011, 0.320, 0.222, respectively. (2)seven morphometric attributes of the Poyang Lake population (carapace length, fantail length, telson width, carapace width, carapace height, telson height, body length) correlated significantly to body weight, where the regression intercept and regression coefficients were -1.618, 0.392, -0.280, 0.703, 0.524, -0.359, 0.688, -0.061, respectively. (3)four morphometric attributes of the Baiyang Lake population (body length, carapace width, second pereiopod length, fantail length) significantly correlated to body weight, where the regression intercept and coefficients were -4.796, 0.082, 0.222, 0.007,0.136, respectively. (4)four morphometric attributes of the Weishan Lake population (carapace length, first abdominal segment height, second pereiopod length, first abdominal segment width) significantly correlated to body weight, where the regression intercept and coefficients were -7.644, 0.248, 0.329, 0.025, 0.301. (5)five morphometric attributes of the Dianshan Lake population(body length, second pereiopod length, carapace width, telson width, frirst abdominal segment width) significantly correlated to body weight, where the regression intercept and coefficients were -6.257, 0.019, 0.018, 0.164, 0.264, 0.162, respectively. It is obviously that the body length and carapace traits in different populations have great effect on the body weight.High multiple-correlation coefficients of the reserved morphometric traits on the body weight in each population were greater than 0.85 (Tai Lake R²=0.965, Poyang Lake R²=0.904, Baiyang Lake R²=0.902, Weishan Lake R²=0.971, Dianshan Lake R²=0.955). The main attributes of each population effecting the body weight were confirmed. The clustering results showed that the closer the geographical location, the more similar the shape in terms of the morphological traits.