牙鲆三倍体批量化诱导及其生长和性腺发育观察

摘要

Induced rate, growth and gonad were studied in triploid Japanese flounder ( Paralichthys olivaceus). The result indicated that triploidy flounder was achieved successfully by cold shocking fertilized eggs at 3 ℃ for 45 minutes duration,3 minutes after fertilization when the temperature of fertilization was 14.8 -15.5 ℃. Regular growth measurements were done on the achieved triploid Japanese flounder and the control group 120 days,348 days and 630 days after that. The results revealed that there was no significant difference in growth between diploid flounder and triploid flounder after 120 days. But the weight was significantly different between them after 348 days(P <0. 05). And the triploid growth rates (full-length, weight)showed extremely significant difference compared to the diploid controls' (P <0. 01). The indexes of the ovaries and the testes in the diploid control were respectively 3.3 and 3.1 times of the indexes of the ovaries and the testes in the triploid Japanese flounder. Furthermore, the gonadosomatic indexes (GSI) of the triploid were significantly higher than the control group' s after 630 days(P <0. 001). From these gonadal sections,a lot of normal oocytes could be found in the section of diploid ovary,but the triploid ovary stayed in the stage of oogonium stage. Meanwhile, the number of spermatocyte in triploid testis was significantly less than that of the number of spermatocyte in diploid testis. The study obtained 100% triploid rate with this method. Meanwhile, the triploid gonad was hypogenetic and the growth rate of the triploidy was significantly higher than the control group. Thus,the triploid is suitable for promotion in production.%对牙鲆三倍体鱼苗的诱导、生长及性腺发育进行了一系列研究,发现在14.8～15.5℃的海水温度条件下授精,授精后3 min将受精卵放入3℃的海水中冷休克处理45 min,可以得到牙鲆三倍体;120日龄、348日龄、630日龄时对三倍体和二倍体的全长和体质量进行测量,发现在120日龄时二倍体与三倍体体质量差异不显著,348日龄时三倍体体质量明显大于二倍体体质量(P＜0.05),630日龄时三倍体的全长和体质量均高于二倍体,且差异极显著(P＜0.01).通过比较630日龄时的性腺指数,发现二倍体牙鲆雌性和雄性的性腺指数分别是三倍体的3.3倍和3.1倍,三倍体牙鲆性腺明显小于二倍体,二倍体和三倍体卵巢指数之间及精巢指数之间差异均极显著(p＜0.001);组织切片观察显示,在二倍体卵巢中可见正常卵母细胞,三倍体卵巢处于未分化的卵原细胞阶段,三倍体精巢中有精母细胞,但数量明显少于二倍体精巢.结果表明,研究采用的方法能够大量获得诱导率为100％的三倍体牙鲆鱼苗,三倍体成鱼性腺发育不良,并且其生长速度显著快于二倍体对照,适合在生产中推广.