Studies On The Distant Hybridization Of Larimichthys Croces (?) And Nibea Miichthioides (?)

In this study, to understand the feasibility of cross breeding between Larimichthys crocea♀and Nibea miichthioides♂, hybridizations were carried out and the growth of their hybrids wascompared with that of L. crocea. Morphological variations and discriminant analysis of habridsand their parents were studies. By using the technology of AFLP and SSR, genetic analysis ofhybrids was carried out. The results were summed up as follows:1. L. crocea (♀) and N. miichthioides (♂) can be successfully crossed and hybrid offspringsof normal survival were produced. Survival rate of hybrid offspring at the age of45days posthatch reached about30%. However, fertilization rate (29.0%,32.6%) and hatching rate (75.0%,76.7%) of two hybrid families were significant lower than those in large yellow croaker families(P <0.05).2. Both body length and full length super-parent vigotous of hybrid offspring at the age of45days post hatch of the two hybrid families were negative and their absolute weight increaserate was lower than that of large yellow croaker families. But during the period of45days to164days post hatch, the increases in full length, body length and body weight of hybrid offspringwere significantly larger than those of large yellow croaker families. By the time of164dayspost hatch, hybrid offspring had a significant growth advantage compared with female parentslarge yellow croaker.3. The body colors of hybrid offspring both included light yellow which came from L.crocea (♀) and grey brown which came from N. miichthioides (♂). The average hybrid index ofmeristic characters was closing to the median value of both parents and the average hybrid indexof measurable characters slightly inclined to male parents. Cluster analysis results showed thathybrid offspring were closer to female parents morpologically. With three discriminant equationsthat were build by using six most contributive parameters chosed from discriminant analysis, thediscriminant accuracy of both patents was100%and hybrid offspring85.7%.4. The results of DNA relative content investigation and genetic relationship analysisdemonstrated that more than90%of the hybrid offsprings were hybrid diploid, in addition, asmall number of those were hybrid triploid and gynogenesis diploid.5. Genetic analysis of seven hybrids at the age of45days post hatch by using six sets ofAFLP and SSR primers showed that the seven hybrids were hybrid diploid and each hyrid’ sparents were successfully found by using locus of difference.