|
|
|
| Induction and Identification of Triploid in Bluntnose Black Bream Megalobrama amblycephala |
| ZHANG Xinhui,LUO Wei,GAO Zexia,YANG Kun,ZHU Dongmei,WEN Jiufu,QIAN Xueqiao,WANG Weimin |
|
|
|
|
Abstract The conditions for induction of bluntnose black bream (Megalobrama amblycephala) triploids by means of cold shock were optimazed and three methods for induction of the triploids were compared . The hatching rate of 34 .31% and triploidy rate of 60 .67% were observed when the fertilized eggs were shocked at 0~2 °C for 25 min 3 min after fertilization and incubated at water temperature of about 26~27 ° C , even though triploidy rate was affected by water temperature , initial time and duration . The measurement of chromosome number count ,DNA content and erythrocyte volume revealed that the fry had 3n=72 chromosomes in artificial triploid and 2n=48 chromosomes in normal diploid .There were very significant differences in DNA contents measured by flow cytometry between the triploid and diploid (P <0 .01) ,the triploids being as large 1 .49 as times of the normal diploid ,especially the volume of nuclear and erythrocyte cells (P < 0 .01) .The ratio of triploids to diploids was found to be 1 .40∶1 in the erythrocyte volume ,and 1 .51∶1 in nucleus volume .The findings indicate that the triploid individuals of bluntnose black bream is accurately identified by the chromosome number ,DNA content and erythrocyte size .
|
|
Received: 25 September 2013
|
|
|
|
|
|
|
