The Analysis of Genetic Variability of mtDNA 12S rRNA Genes in the Allotetraploid, Triploid Crucian Carp and their Parents
异源四倍体鲫鲤、三倍体湘云鲫和它们父母本线粒体DNA 12S rRNA基因遗传变异的分析

The complete 12S rRNA genes from the five F (11) allotetraploids, two diploid gynogens, two triploid crucian carps, one red crucian carp, one xiangjiang common carp, and one Japanese crucian carp were successfully cloned and sequenced. Sequence compositions and variations were analyzed with MEGA 1.0 software. Five F (11) allotetraploids shared two haplotypes, and two diploid gynogens, two triploid crucian carps, one red crucian carp, one xiangjiang common carp, one Japanese crucian carp shared one haplotype, respectively. The similarities among red crucian carp, xiangjiang common carp, allotetraploid, diploid gynogen, Japanese crucian carp, and triploid crucian carp varied from 95% to 99%. The similarities between allotetraploid, triploid crucian carp and their female parents (red crucian carp and Japanese crucian carp, respectively) were higher than those between allotetraploid, triploid crucian carp and their male parents (xiangjiang common carp and allotetraploid, respectively). Such result indicated that mitochondrial 12S rRNA genes of the allotetraploid and triploid crucian carp were inherited maternally. A phylogenetic tree was reconstructed using the neighbor joining method of the MEGA package. It was noticeable that after nine generations from F 3 to F (11) hybrids, the five F (11) allotetraploids shared two haplotypes (AT-1 and AT-2), indicating the allotetraploid stock had the genetic diversity. The results provided some valuable information for the breeding, genetic conservation, and population rejuvenation of the tetraploid stock.