Study On The Low Temperature Dormancy And Survival Transportation Technology Of Pengze Crucian Carp (Carassius Auratus Var.Pengze)

In this paper,pengze crucian carp as object which is a famous aquatic product in Jiangxi province.the effects of the factors on survival time of pengze crucian carp were studied,including temperature,oxygen,fasting time and so on.On this basis,the survival technology of pengze crucian carp was established by single factor and orthogonal experiment in summer and winter,and the changes of quality and physiological functions in genes' transcriptional expression of pengze crucian carp were studied during keeping alive at low temperatures without water in winter.The effects of oxygen supply mode,survival temperature,gradient cooling rate,ratio of fish and water mass,fasting time and addition of Na Cl on pengze crucian carp survival time were studied by single factor experiment in summer.On this basis,an orthogonal experiment with 4 factors and 3 levels was designed by select the factors that have great influence on survival time in summer,and the primary and secondary order of the factors effecting on survival time of pengze crucian carp is as follow: survival temperature?addition of Na Cl?ratio of fish and water mass?fasting time.The optimized conditions for survival technology in summer were ensured: stop feeding,24 h;rate of cooling is 3 ?/h at 30~20 ? and rate of cooling is 2 ?/h at 20~7 ?;fish/water mass ratio,1:1(g/g);addition of Na Cl,0.3%;survival temperature of 13±1? under pure oxygen.The survival time of pengze crucian carp under the optimized conditions was 148 h in summer.The dormancy temperature and freezing temperature of pengze crucian carp were determined and the ecological ice temperature range of pengze crucian carp is confirmed through the principle of ecological ice temperature in winter.The effects of the elements on its' survival time by single factor experiments,including oxygen supply mode,survival temperature,rate of gradient cooling,fasting time in winter.Further,the primary and secondary order of the factors effecting on survival time of pengze crucian carp is as show: survival temperature?fasting time?rate of gradient cooling through orthogonal experiment.The optimized conditions for survival technology in winter were ensured: stop feeding,82 h;rate of cooling is 2 ?/h at 17.5~10 ? and rate of cooling is 1 ?/h at 10~3 ?: dormancy;offer pure oxygen;survival temperature of 1 ? under thermostat box.The survival time of pengze crucian carp under waterless and ecological ice temperature was 148 h in winter.Compared to fresh crucian carp,it is found that the quality,the capacity of water holding,rate of cooking loss and TVB-N value of the muscle were not significantly changed under keep alive in the ice temperature without water,but hardness and chewiness of the muscle were decline,this may be because that the glycogen of muscle is decomposed into water and carbon dioxide and the increase of water in the muscles.In addition,the proportion of amino acids in muscle have been changed,and the total amount of essential amino acids were increased,however,the total amount of fresh amino acids was to increase of K value slightly,but the freshness was limited effect.The results showed that quality and nutrition of pengze crucian carp remained well before and after the survival under ice temperature without water.We got 271047 Unigenes which have 263391 annotated information by RNA high throughput sequencing in liver of pengze crucian carp before and after survival.There were 201 differently expressed gens including 133 up-regulated and 68 down-regulated at between experimental and control groups' Unigenes.Further,the enrichment of KEGG pathway and GO function annotation showed that gene expression with differentiation of glandular epithelial cells and pancreatic cells were up-regulated for DEGs.And the pathway of immune system and cell apoptosis were up-regulated and enrichment.This indicated that all of metabolic process,the immune system,the stress reaction process was involved in the response to low temperature stress and resist the low temperature injury.As a result,the organism can regain new balance to adapt to the low temperature environment and survival.