Interspecific hybridization of Quasipaa and genetic characteristics of hybrid tadpole

This study aims to reveal the formation mechanism of distant hybridization of Quasipaa . We collected five species of Quasipaa for hybridization experiment and raised tadpoles at three temperature groups (14 ℃, 22 ℃, and 28 ℃) and three density groups (5, 15, and 30 ind/L). We monitored the growth rate and swimming speed of the tadpoles. We also used nine microsatellite markers to evaluate genetic diversity and structure between the crossbred offspring and parents. Results suggested that the hybrid combinations of Quasipaa spinosa (♀) × Q. shini (♂) and Q. boulengeri (♀) × Q. spinosa (♂) obtained healthy crossbred offspring. Temperature and breeding density significantly affected the growth and development of purebred and crossbred tadpoles. Compared with purebred tadpoles, the hybrids showed heterosis under similar experimental conditions. The genetic diversity of the crossbred tadpoles was higher than that of the parents. Higher heterozygosity and genetic differentiation were also observed in the progeny population. A close genetic relationship was found between the offspring population and the female parent.