| 摘要: |
| 将美国雄性四倍体长牡蛎与中国北方海区雌性二倍体长牡蛎杂交, 进行全三倍体长牡蛎培育研究。结果表明, 四倍体与二倍体杂交的受精率为47.4%─88.9%, 平均为69.5%；来自同样雌贝的二倍体对照组的受精率平均为91.4%。杂交组和对照组面盘幼虫的平均孵化率分别为53.9%和61.6%；受精卵发育至稚贝的存活率, 杂交组和对照组分别为1.3%和1.9%。杂交组累计培育出眼点幼虫8.324亿, 稚贝1.843亿。杂交组幼虫的生长略快于对照组, 但无显著差异。经流式细胞仪分析, 杂交组的幼虫、稚贝、幼贝等均为100%三倍体。中国北方海区的长牡蛎可以与美国的雄性四倍体长牡蛎实现良好的杂交, 产生100%三倍体。利用长牡蛎四倍体培育三倍体, 方法简便高效, 显示出四倍体在贝类三倍体商业生产中的巨大应用价值。
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| 关键词: 长牡蛎,四倍体,三倍体,杂交,流式细胞术 |
| DOI：10.11693/hyhz200306010010 |
| 分类号: |
| 基金项目:国家杰出青年基金资助项目,39825121号;青岛市科委资助项目,99-1-2-8-3号,00-1-5-1号;山东省博士基金资助项目,2000410号 |
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| ALL-TRIPLOIDS PRODUCTION BY CROSSING MALE TETRAPLOIDS WITH FEMALE DIPLOIDS IN PACIFIC OYSTER, CRASSOSTREA GIGAS THUNBERG |
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QUE Hua-Yong1, ZHANG Guo-Fan1, LIU Xiao1, GUO Xi-Ming2, ZHANG Fu-Sui1
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1.Institute of Oceanology, The Chinese Academy of Sciences;2.Haskin Shellfish Research Laboratory, Institute of Marine and Coastal Sciences, Rutgers University
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| Abstract: |
| All-triploids were produced by mating female diploids and male tetraploids in Pacific oyster, Crassostrea gigas Thunberg (referred to as DTgroups), along with diploid controls using eggs from the same female diploids (referred to as DD groups). Tetraploid brood stocks were introduced from USA with the help of the 4C Company. Upon arrival at the experiment sites, tetraploid brood stocks were kept in seawater at 4℃ till use to prevent spontaneous spawning. Both eggs and sperm were obtained by strip-spawning. Fertilization levels ranged from 47.4% to 88.9%, averaging 69.5% in DT groups, while the mean fertilization in DD controls was 91.4%. There was significant difference in fertilization success between the DT and DD groups (P<0.01). Compared with DD groups, the reduction in fertilization in DT groups was primarily attributed to high egg density in order to fully utilize sperm from tetraploids. Survival from fertilized eggs to D-stage larvae and spat averaged 53.9% and 1.3% respectively in DT groups, compared to 61.6% and 1.9% respectively in controls. There was no significant difference in survival to D-stage and spat between DT and DD
groups. The total amount of eyed larvae and spat obtained from DT groups were 832.4M and 184.3M respectively. Larvae from DT groups were slightly larger than those from controls throughout larval development. However, larvae from DT and DD groups had the similar growth following formation of straight-hinge larvae. Flow cytometry is used to verify the ploidy composition of tetraploid brood stock and of progeny from DTgroups. Random samples of D-stage larvae, eyed larvae and spat from DT groups were consistently 100% triploids. The key point of producing all-triploidsby crossing tetraploids with diploids was the prevention of contamination from diploid cultures, especially when diploid progeny were cultivated simultaneously. There were evidences that contamination of diploids resulting in remarkable reduction in triploid percentage of previously verified 100% triploid stocks in some of the replicates in this study. Results presented here demonstrate that female diploid C. gigas stocks from North China could be readily mated with male tetraploids from USA and produce 100% triploids on a large scale. Overall, this study shows that tetraploids are extremely valuable for large-scale of production of triploids, and mating diploids and tetraploids is an ideal approach of all-triploid production in C. gigas.
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| Key words: Crassostrea gigas, Tetraploids, Triploids, Cross, Flow cytometry |
