三疣梭子蟹自交与杂交家系子一代生长和存活的比较

Comparison of growth and survival of the hybrid and inbred families of Portunus trituberculatus

选择繁殖性能好的A家系(F6)和生长与存活好的B家系(F3),设计家系内自繁和家系间杂交,比较其自交组与杂交组子一代的生长与存活,评价杂交效应。由自交组F66(A♀×A♂)、F33(B♀×B♂)和杂交组F63(A♂×B♀)、F36(B♂×A♀)4个实验组组成,比较各实验组子一代在80、100、120、150日龄时的各生长指标杂种优势。研究表明,同一生长发育阶段的同一杂交群体的不同性状,表现的杂种优势大小有很大差异,而且同一杂交群体的同一性状在不同生长发育阶段表现的杂种优势大小同样有差异。自交组各阶段全甲宽、甲宽、甲长和体高的生长趋势比较一致,为F33>F66;不同生长性状的生长速度方面,杂交组具有不同程度的总体杂种优势(-3.50%-19.47%)。结果显示,就存活而言,杂交组比自交组的存活率杂交优势明显,总体杂种优势率为24.8%,与存活相关的养殖产量的总体杂种优势率为15.99%,无论是生长性状还是存活,杂交使A家系获得的改良效果比B家系的好。A、B两个家系间存在的遗传差异获得杂种优势,是性状得到改良的基础。

In this study we compared the reproductive performance of female parents, growth of these filial generations, survival, and yield of six inbreeding generations （ F1-F6） of full-sib families of Portunus trituberculatus. The statistical methods applied in the study were single factor analysis of variance （One-Way ANOVA）, least significant difference （LSD）, multiple comparison analysis, and analysis of covariance. We set up the reproduction between two full-sib inbreeding families （F3-F6）, Pedigree A （F6 ） and B （F3 ）, at different genetic purification degree. There are four exoerimental groups, of which there are two inbreeding groups F66（A♀×A♂） and F33（B♀×B♂） and two hybrid groups F63（A♂×B♀） and F36（B♂×A♀）. By comparing the growth of filial generations of four experimental groups during the outdoor periods, we found that at 80-day, 100-day, 120-day and 150-day, different characters of the same hybrid group had different heterosis at the same growth stage, and the same character of the same experimental group also had different heterosis at different growth stages. In inbreeding groups, different characters had the same growth trend as F33 〉 F66. As for the growth rate, the hybrid groups showed overall heterosis （ -3.50% to 19.47% ） with different heterosis levels in individual characters. In terms of survival, hybrid groups showed significant heterosis compared to inbred groups with a heterosis rate of 24.8%, and the overall heterosis of 15.99% in the yield associated with survival. Family A benefited more from the hybridization than Family B regarding both the growth characters and the survival, which was consistent with the results of early growth study in the four sub-generation experimental groups. Genetic differences between Family A and B were the basis of potential heterosis and improvements in characters.