基于C-R模型比较大菱鲆快速生长品系和普通养殖群体的生长特征

大规模家系选育技术也称为现代育种技术,具有选择效率高、可抑制遗传衰退等优点,是进行分子辅助育种技术的基础。基于此,采用这项技术开展了大菱鲆快速生长性状遗传改良研究。为了系统评估大菱鲆快速生长选育的育种成效,运用C-R模型分别对选育出的大菱鲆快速生长品系和普通养殖群体的非线性生长曲线进行了拟合和比较分析,深入揭示选育出的大菱鲆快速生长品系和普通养殖群体的生长差异。研究结果显示,快速生长品系和普通养殖群体C-R模型的拟合度、拐点月龄、拐点体质量、最大月增体质量分别为0.999和0.997、15.228和16.858月龄、716.712和619.862 g、111.711和78.061 g;快速生长品系的瞬时生长率、瞬时生长加速率、相对生长率分别在4.5~25月龄、3~13.8月龄、3~15月龄,高于普通养殖群体,在其他相应阶段,快速生长品系的瞬时生长率和瞬时生长加速率低于普通养殖群体,而相对生长率无显著差异;快速生长品系的始速点、拐点和终速点均比普通养殖群体提前,并且快速生长期时间区间长度(12.35月龄)小于普通养殖群体(15.28月龄),其对应的体质量区间长度(1 187.680 g)大于普通养殖群体(1 027.120 g),即基于家系选育技术获得的大菱鲆快速生长品系在较短的快速生长时间区间范围内,获得了更大的净增体质量,取得了更大的遗传进展。

Comparison of growth dynamics between a selected fast-growing strain and the common cultured strain of turbot (Scophthalmus maximus) based on C-R model

In order to evaluate success in selective breeding of Scophthalmus maximus, the nonlinear growth curves of a selected fast-growing strain and the common cultured strain were fitted using Chapman-Richards (C-R) model, and the differences in growth performance of the two strains have been deeply investigated. The results showed that the goodness of fit (R²), time to inflection, weight at inflection and maximum month gain of fast-growing strain and common cultured strain were respectively 0.999 and 0.997, 15.228 and 16.858 months old, 716.712 and 619.862 g, 111.711 and 78.061 g. The instantaneous growth rate, growth acceleration rate and relative growth rate of fast-growing strain were higher than those of common cultured strain during months of 4.5–25, 3–13.8 and 3–15 months old, respectively. However, the instantaneous growth rate and growth acceleration rate of fast-growing strain were lower than those of common cultured strain in other growth stages, and the relative growth rate is almost the same. Furthermore, the fast-growing strain showed earlier starting point (9.05 months old), inflection point (15.23 months old) and ending point (21.40 months old), shorter fast-growing period time interval (12.35 months old) and longer fast-growing body weight intervals (1 187.680 g) than those of common cultured strain. Obviously, the selected fast-growing strain has obtained greater net body weight increment during fast-growing period in a relatively short time.