A REVIEW OF GENETIC-IMPROVEMENT OF THE COMMON CARP (CYPRINUS-CARPIO L) AND OTHER CYPRINIDS BY CROSSBREEDING, HYBRIDIZATION AND SELECTION

Genetic research and application have mainly focused on the common car p, while little attention has been given to Chinese and Indian carps. The only exceptions are interspecific and intergeneric hybridization i nvolving the latter species. The common carp is the only species for w hich distinct varieties exist. Several of these have been used for cro ssbreeding, and heterosis for growth was shown to be common though not a universal phenomenon. Crossbred carp heterotic for growth rate and cold tolerance are commercially cultured, Many interspecific cyprinid hybrids were produced, but most of them are of no applied importance. Commercial breeds of common carp possessing improved disease resistanc e and production characteristics have been developed by selection, mai nly in the former Soviet Union. The few genetic improvement projects e merging recently, especially in China and India, can benefit from the approaches and procedures that have been successfully applied to the g enetic improvement of the common carp.