香港牡蛎野生群体家系建立及耐高盐性筛选

Establishment of families and subsequent high salinity resistance testing for wild population of Crassostrea hongkongensis

【目的】选育出香港牡蛎(Crassostrea hongkongensis)耐高盐品系,为提高其养殖经济效益和促进产业持续发展提供保障。【方法】以广西茅尾海海区野生香港牡蛎为亲本,采用♂∶♀=1∶3的交配方式建立30个香港牡蛎野生群体全同胞家系,比较各家系早期的生长性状差异,并对30个家系在高盐度(25‰～30‰)自然海域的生长和存活率进行监测,对香港牡蛎耐高盐性进行筛选。【结果】各家系间的受精率及孵化率无显著差异(P>0.05,下同)。在幼虫培育过程中,至15日龄时以家系G_1的壳高最大,家系I_1的壳高最小,二者差异显著(P<0.05);以G为父本的半同胞家系存活率较低,均低于平均值(63.21%);而以D为父本的3个家系存活率较高,均超过71.33%。海区养殖期间,至60日龄时各家系均表现出较高的存活率,保持在90.00%以上;至120日龄时,除家系B_1、B_2、B_3、E_1、I_1、J_1、J_2和J_3外,其他各家系的存活率均为0;至300日龄时家系B_1、B_2、B_3、I_1、J_1和J_2的存活率在40.23%～60.32%。不同家系的壳高在相同日龄差异明显,养成期至300日龄时,家系B_2的壳高最大,但与家系B_1和J_3的差异不显著;以家系E_1的壳高最小。【结论】通过家系建立结合高盐海域养殖的方式筛选获得B_1、B_2、I_1、J_1和J_2等优良家系,可为香港牡蛎耐高盐品系选育提供种质资源。

【Objective】High-salt-tolerance strains of Crassostrea hongkongensis were bred to provide support for improving its breeding economic benefits and promoting industrial sustainable development.【Method】Wild C.hongkongensis in Maowei Sea,Guangxi was used as parent.Thirty full-sib families of wild population of C.hongkongensis were established using artificial insemination(♂∶♀=1∶3).The differences of phenotype characters in early growth stage were compared.The growth and survival rates of the families in the natural sea with high salinity(25‰-30‰)were monitored,and the high-salinity tolerance of the oysters were screened.【Result】The results showed that there was no significant difference in fertilization rate and hatching rate among families(P>0.05,the same below).In the larval stage,shell height of G1 grew the highest on 15 day-age,and that of the I1 was the shortest,the difference between them was significant(P<0.05).The survival rates of the three families with G as the male parent were low,which were lower than the average(63.21%).The three families with D as the male parent had high survival rate,all of which exceeded 71.33%.During the sea culture period,at 60 days of age,the survival rate of each family was high,all of which were over 90.00%.At 120 days of age,except for B1,B2,B3,E1,I1,J1,J2,and J3,the survival rate of each family was zero.Families B1,B2,B3,I1,J1 and J2 were found with a survival rate of 40.23%-60.32%at the age of 300 days.With the highest shell height,the shell height of B2 was not significantly different from that of B1 and J3.The shell height of E1 was the shortest.【Conclusion】In this experiment,a group of outstanding families,such as B1,B2,I1,J1 and J2,are obtained through family establishment and high salinity sea culture.It provides germslasms for C.hongkongensis breeding and selection with high salinity tolerance.