Genetic parameter evaluation for growth and cold resistance traits of the giant freshwater prawn Macrobrachium rosenbergii

The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.

T-IP: A Self-Trustworthy and Secure Internet Protocol

IPsec has become an important supplement of IP to provide security protection. However, the heavyweight IPsec has a high transmission overhead and latency, and it cannot provide the address accountability. We propose the self-trustworthy and secure Internet protocol(T-IP) for authenticated and encrypted network layer communications. T-IP has the following advantages:(1) Self-Trustworthy IP address.(2) Low connection latency and transmission overhead.(3) Reserving the important merit of IP to be stateless.(4) Compatible with the existing TCP/IP architecture. We theoretically prove the security of our shared secret key in T-IP and the resistance to the known session key attack of our security-enhanced shared secret key calculation. Moreover, we analyse the possibility of the application of T-IP, including its resilience against the man-in-the-middle attack and Do S attack. The evaluation shows that T-IP has a much lower transmission overhead and connection latency compared with IPsec.