The available information on the inheritance of complex multi-color types of ornamental (koi) common carp is very scarce, in spite of a long term history of cultivation. Comparisons of color variability between normal and gynogenetic progenies were made in order to gain some information on this subject. Two classes of progenies were obtained from three females of different multi-color types: amphirnictic (A) progenies produced by crossing each female with a male of the same color type, and meiotic gynogenetic (G) progenies produced by applying early heat-shock (at the 2nd meiosis) to eggs inseminated with genetically inactivated sperm. The color types of the females used were: white-red-black (Taisho-Sanke variety, according to Japanese classification), white-black (Shiro-Bekko) and white-red (Kohaku).All possible coloration types were recorded among the progenies produced by the tricolor female. Many fish (42.5% and 40.2%, respectively) in both A and G progenies had the parental white-red-black coloration, while the rest were white-red (10.5% and 20.6%, respectively), white-black (15.4% and 12.4%), red-black (20.6% and 19.6%), red (6.6% and 3.1%) and white (4.4% and 4.1%). Similar color variability was observed in progenies obtained from the white-black female. White-red-black fish prevailed again (44.0% and 37.0%, respectively) in both A and G progenies. The proportions of the parental white-black type (28.2% and 33.4%) and the white (7.3% and 14.1%) were higher than among the progenies of the tricolor females, while that of red, white-red and red-black were lower. Nearly half (45.7% and 47.8%, respectively) of the offspring of the white-red female in both A and G progenies, had the parental white-red coloration. The rest were either white or red.The high color variability in A progenies, produced by crossing females and males of the same color type, confirms that koi varieties tested are not genetically fixed, and have complex inheritance. Normal and gynogenetic progenies originated from fish of the same genotype are expected to differ in allele segregation, since the frequency of heterozygotes among meiotic gynogens depends on genecentromere recombination rate. However, in the present investigation the proportions of different color types did not differ significantly (P > 0.05) between the A and corresponding G progenies. We, therefore, suppose that the investigated multi-color types arise from inter-loci rather than inter-allelic interactions.
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