Quality Analysis and Evaluation of Scylla paramamosain from Three Different Areas

[Objectives]The quality of Scylla paramammosain produced in Fujian,Sanmen and Shanghai were analyzed and evaluated.[Methods]Adult Scylla paramammosain from Fujian,Sanmen and Shanghai were separated for their muscles and gonads,which were analyzed for nutritional components.[Results]The muscle moisture content of S.paramammosain from Sanmen was significantly higher than those in S.paramammosain from Fujian and Shanghai.The muscle protein contents of S.paramammosain from the three regions ranked as Shanghai>Fujian>Sanmen(P<0.05).The muscles of S.paramammosain from Shanghai had the highest crude fat and crude ash contents.The moisture contents of the gonads of the S.paramammosain from the three regions had no significant differences.The protein contents of the gonads of S.paramammosain from the three regions ranked as Shanghai>Sanmen>Fujian(P<0.05).The S.paramammosain from Sanmen had the highest crude fat and crude ash contents in gonads.The contents of 17 amino acids detected in the muscles and gonads of S.paramammosain from the three different regions were different.The total amounts of total amino acids(TAA),essential amino acids(EAA)and flavor amino acids(FAA)in the muscles of S.paramammosain from Sanmen were significantly lower than those produced in Fujian and Shanghai(P<0.05),but the proportions of essential amino acids(EAA)and flavor amino acids were not significantly different.The proportion of EAA and FAA in the gonads of S.paramammosain produced in the three areas were significantly different(P<0.05).There were also differences in the fatty acid composition of the muscles and gonads of S.paramammosain from the three different regions.The proportion of EPA in the muscles of S.paramammosain from Fujian was higher than those of other two groups,but the differences were not significant;the proportion of DHA was significantly higher than those of other two groups,and the differences were significant(P<0.05);and the proportions of n3 PUFA in muscles of S.paramammosain produced in Fujian and Sanmen were significantly higher than that of S.paramammosain produced in Shanghai(P<0.05).The proportions of EPA,DHA and n6 PUFA in the gonads of S.paramammosain produced in Sanmen were significantly higher than those produced in Fujian and Shanghai(P<0.05),while the n3 PUFA was the highest in S.paramammosain produced in Fujian.The proportions of n6/n3 PUFA in S.paramammosain produced in the three different regions were significantly different(P<0.05).In summary,it could be seen that the nutritional composition of S.paramammosain produced in different regions has its own characteristics.[Conclusions]This study provides basic data for the establishment of quality evaluation standards for S.paramammosain,and provides a new perspective for the evaluation of breeding models.

Optimizing protein and lipid levels in practical diet for juvenile northern snakehead fish(Channa argus)

A 3×3 factorial feeding trial was conducted to evaluate the production response of juvenile northern snakehead fish(Channa argus). Nine diets containing 3 protein levels(45%, 48% and 51%) and 3 lipid levels(9%,12% and 15%) were formulated and fed to triplicate groups of juvenile northern snakehead(15.78 ± 0.09 g/fish) for 8 weeks. The formulated diets were named as P45 L9, P45 L12, P45 L15, P48 L9,P48 L12, P48 L15, P51 L9, P51 L12 and P51 L15(P-Protein, L-Lipid), respectively. Fish fed diets with the lowest protein and lipid combination(P45 L9) had the lowest growth performance. Weight gains(WG) of fish fed the 4 diets P48 L12, P48 L15, P51 L9, and P51 L12 were not significantly different(P> 0.05), but significantly higher(P < 0.05) than those of fish fed the other diets. Fish fed diets P48 L12 and P48 L15 had significantly lower(P < 0.05) feed conversion ratios(FCR) than the rest of the treatments. Protein retentions(PR) among fish fed the diets P45 L12, P45 L15, P48 L12, P48 L15, P51 L9, and P51 L12 were similar and significantly higher(P < 0.05) than those of fish fed the remaining diets. Protein sparing effect was observed in the treatments when fish was fed diets containing 45% or 48% dietary protein levels with dietary lipid increased from 9% to12%. Fish fed diets with 9% lipid tended to have lower viscerosomatic index(VSI), hepatosomatic index(HSI),and whole-body lipid. Increasing dietary protein level significantly increased(P < 0.05) liver moisture and lipid while dietary lipid level increased liver lipid. Intestinal lipase activity increased significantly(P < 0.05)with increasing dietary lipid and protein levels while intestinal a-amylase and protease activities were not significantly influenced(P > 0.05) by dietary treatments. Based on these results, the diet containing 48%protein with either 12% or 15% lipid is the optimal for supporting growth and feed utilization of juvenile northern snakehead under the current testing conditions.

Reactive oxygen species regulate auxin levels to mediate adventitious root induction in Arabidopsis hypocotyl cuttings

Adventitious root(AR)formation from leafy stem cuttings is critical for breeding of many forest and horticultural species.In addition to the plant hormone auxin,wound-induced signaling caused by the cutting excision is also essential for AR initiation.Here we found that reactive oxygen species(ROS)are rapidly generated at the excision site as a wound-induced signal and propagated throughout the hypocotyl cut-ting after excision of the Arabidopsis(Arabidopsis thaliana)primary root.ROS propagation was not ob-served in the presence of an NADPH oxidase inhibitor(diphenylene iodonium chloride)or in a knockout mu-tant of the NADPH oxidase gene respiratory burst oxi-dase homolog protein D(RBOHD).Respiratory burst oxidase homolog protein D was specifically upregulatedin hypocotyl cuttings at 0.5 h post excision(hpe).To-gether,these data suggest that RBOHD mediates ROS propagation in hypocotyl cuttings.We also found that auxin levels increased significantly in the shoot apex at 5 hpe and at the base of the cutting at 6 hpe;these effects were blocked by treatment with ROS scav-engers.Consistent with this,transcript levels of auxin biosynthesis and polar-transport genes generally in-creased between 1 to 6 hpe.Collectively,our results suggest that wound-induced ROS participate in AR in-duction through regulation of auxin biosynthesis and transport.