PIT marker assisted family establishment in rainbow trout and rapid growth families screening

Abstract

Cold-water fish culture first began in China in 1959 with a shipment of eyed eggs and fry of rainbow trout(Oncorhynchus mykiss) from the Democratic People's Republic of Korea.Since then,rainbow trout culture has expanded rapidly into more than 22 provinces.However,further advances depend on accelerating the process of selective breeding and preventing the genetic degeneration of this species.We evaluated the utility of PIT marker assisted selection using a generation one(G1) of a rainbow trout superior strain population which was be-ing selectively bred by the Heilongjiang River Fishery Research Institute(HRFRI) of the Chinese Academy of Fishery Sciences(CAFS).We developed 72 rainbow trout families using PIT marker assisted technology.All pedigreed fry were implanted with PIT markers and cultured in the same pond.Body weight and body length were measured for all the market size rainbow trout individuals 850 days after fertilization to screen for rapid growth families.The family effect was highly significantly for both body weight and body length(P0.01).We obtained 8 rapid-growth families in which the family effects for body weight and body length were both significant(P0.05).The family numbers were 682BABB,6717B7A,6828308,682A50A,6829C24,6829DC7,682A382,and 68284DA.Our results may be compared with our previous work based on BLUP analysis of individual estimated breeding values.Our study provides insight into methods for improving the accuracy of genetic selection for growth traits in rainbow trout,and for genetics and breeding research into quantitative traits in other aquatic ani-mals.