6-DMAP诱导栉孔扇贝异源雌核发育二倍体

采用紫外线遗传灭活的长牡蛎精子激活栉孔扇贝卵子，运用L9（3^4）设计不同6-DMAP的处理条件来诱导染色体加倍，获得第二极体抑制型栉孔扇贝雌核发育二倍体早期胚胎。以雌核发育担轮幼虫为材料，滴片法制备染色体并采用计数法统计倍性，分析不同6-DMAP浓度、诱导时机和诱导持续时间对雌核发育二倍体诱导率的影响，并统计早期胚胎畸形率。结果表明，不同6-DMAP浓度、诱导时机和诱导持续时间对异源精子诱导栉孔扇贝雌核发育二倍体的诱导率均有显著影响；早期胚胎畸形率与二倍体的诱导率呈负相关，y=46.632-0.891x（r=-0.813，P〈0.01）。6-DMAP诱导栉孔扇贝雌核发育二倍体的最佳处理条件为：20%～25%受精卵排放出第1极体时，60μg/ml的6-DMAP持续处理25min可得到最高的诱导率为29.5±5.36%。研究结果为6-DMAP诱导栉孔扇贝雌核发育染色体加倍提供了一定的细胞学依据和技术参数。

Allogynogenetic diploidy of Chlamys farreri induced by 6-DMAP

The eggs of Chlamys farreri were activated by ultraviolet-irradiated heterogenous sperms of Pacific oyster Crassostrea gigas and the pro-embryos were induced by inhibiting extrusion of the second polar body from fertilized eggs with 6-DMAP. Those eggs were treated with different parameters of 6-DMAP which were designed in the method of orthogonal experiment design L9 （3^4）. It was found that the occasion of starting time, the length of the treatment time and the concentration of 6-DMAP were important factors to affect the derivational rate of diploids. The statistic data of the trochophores＇ chromosomes in the nine groups was analysed with the software SPSS11. 5. Results showed that all the three factors had prominent effect on the derivational rate of diploids; the relationship between the rate of malformed embryos and the rate of diploids was negative correlation and the equation was y = 46. 632- 0. 891x （r=- 0. 813 ,P〈0. 01）. Based on the relationship between derivational rate of diploids and the rate of malformed embryos, in the stated range, it was confirmed that the optimal inducing condition of 6-DMAP for gynogenesis in the C. farreri was that the eggs were to be treated with 6-DMAP at the concentration of 60μg per ml for 25 minutes when of the fertilized eggs expelling first polar body 20% to 25%. In this way, 29.5±5.36% diploidinduction could be got. In this study, the states of poly ploidy yield in the treatment groups were also discussed.