Heterosis Analysis Of Hybrid F1 Of England And Spain Turbot (Scophthalmus Maximus L.)

Nowadays turbot (Scophthalmus maximus) has been an economically important aquaculture species in China since imported in 1992. However, inbreeding depression and other problems have been affecting the sustaining development of its industry because of the absence of appropriate program of importation and breeding. Therefore, it is necessary to take some measures to improve the genetic background of turbot. This research studies the hybridization result of two farmed stocks of turbot, and analyses the possible reason of heterosis by AFLP. The main results are as follows:1. The hybridization result of two farmed stocks of turbot was analyzed. Using complete diallel crosses, the first generation of 4 combinations, S♂×S♀, E♂×E♀, S♂×E♀and E♂×S♀were obtained from mating and crossing within and between S (Spain) stock and E (England) stock of turbot. Comparisons of fertilization rate, hatch rate, malformation rate, body length (BL) and body weight (BW) of 30 and 70 days among four groups were done in this study. The results showed that there were no significant differences between the hybridization groups and self-fertilized groups on the fertilization rate, hatch rate, and malformation rate. But, as far as the BL and BW of 30 and 70 days were concerned, the hybridization groups showed obvious heterosis when compared with self-fertilized groups. Heterosis of BL reached 5.43% in S♂×E♀(Day 30) and BW attained 25.00% in E♂×S♀(Day 70). It was concluded that the crosses between different farmed stocks may be an effective way for genetic improvement of turbot.2. We apply the AFLP (Amplified Fragment Length Polymorphism) analysis system to turbot. The results of several reactions during AFLP analysis have been detected such as DNA extraction, double enzymes digestion, adapter ligation,...