Crossbreeding of Different Geographical Populations of Stichopus japonicus

For exploring the genetic differences between groups and the relationship between diversity and genetic distance of Stichopus japonicas,crossbreeding among different populations of Stichopus japonicas were conducted to determine the crossbreeding feasibility.The growing situation of hybrid progeny were observed.The results showed that all the hybrid combinations could get normal hybrid offspring.The fertilization rate was lower compared with combination of inbred with no significant difference;In addition,different hybrid growth advantages were detected in different crossing populations which varied with genetic distance.The crossing offspring showed bigger at both ends and smaller in the middle in six parent combination the genetic distance of which were in the range of 0.285 3~0.423 8.The combination F with genetic distance greater than 0.4 grew fastest.The crossbreeding offspring of combination E which had near genetic distance with combination F,grew slowest at the beginning,and grew faster with times.There were no significant correlation between the genetic distance of hybrid combination and growth characteristics.