Ploidy level, morphological characteristics and performance of interploid hybrids by Megalobrama amblycephala [female] x allo-tetraploids [male].

摘要

Interploid hybrids were produced by mating allo-tetraploid males, an interspecific tetraploidy induced by blunt snout bream (Megalobrama amblycephala) [female] x black bream (Megalobrama terminalis) [male], with blunt snout bream females. The fertilization rate was high in the interploid hybrids. Although significant (P<0.05) mortalities were observed at hatching, swim-up and 30-day stages, respectively, the survival percentage of the interploid hybrids became stabilized after the 60-day stage. In different interploid hybridization batches, 64-97% of juveniles were identified as 3n and 1-36% as 2n. Less than 2% of tetraploids were obtained in these interploid hybridization batches. The daily growth rate of the interploid 3n increased 7.5%, compared with that of diploid blunt snout breams during the 180-day culture. Moreover, a method using seven morphological parameter ratios was set up with a relatively high classification accuracy of 93.8% to harmlessly discriminate interploid 3n from allo-tetraploids, black bream and blunt snout bream.Digital Object Identifier http://dx.doi.org/10.1111/j.1365-2109.2010.02765.x