Cathepsin B (CatB) cDNA of 759 bp from Jian carp (Cyprinus carpio var. Jian) with amino acid similarity of 99.6% to common carp was cloned. The mature CatB was expressed in Escherichia coli BL21 transferred with vector CatB-pET-30a. It was purified and identified as a single band (29 kDa) on SDS-PAGE. Optimum CatB activity was observed at 40 °C and pH 5.5. Mouse anti-CatB polyclonal antibody with a high titer of 1:256000 was prepared successfully and shown to specifically recognize the antigen both in prokaryotic cells and in the tissues of Jian carp according to western blotting and immunohistochemistry results. Immunolocation analysis showed that CatB distribution at protein level varied among the tested tissues. The results presented in this study may provide a significant reference for future research on the inherent relationship between CatB and the quality of fish or fish products at both the gene and protein levels.

This paper conducts a study of the inhibitory effect of trehalose on the protein denaturation of grass carp frozen surimi.At first,salt-soluble protein,total sulfhydryl,Ca2+-ATPase activity and carbonyl group were monitored during the frozen-storage period (12 weeks).When the addition of trehalose was 6％,the inhibitory effect on protein denaturation was the best.Then,the determination of structure characteristics of the group with the addition amount (6％) was conducted after surimi was frozen for six months.Results:the gel strength of the group with best addition amount reached 3 026 g · mm,much higher than the control group (P＜0.01).Scanning electron microscope found that ultrafine 3-dimentional network structureof surimi gel was firmer,more compacted and tougher.The trehalose (6％) has an inhibitory effect on the protein denaturation of grass carp frozen surimi,delays the reduction of frozen surimi quality,and has a good application prospect as a potential commercial surimi antifreeze.

[目的]采用碱性蛋白酶水解草鱼鱼鳞制备抗氧化肽,并探讨其稳定性.[方法]运用单因素及正交试验对酶解条件进行优化,并进行体外抗氧化活性的测定,对酶解得到的抗氧化肽进行体外模拟胃肠消化实验.[结果]在优化工艺条件下,鱼鳞酶解液中羟自由基清除率为88.71%;其体外抗氧化能力随肽质量浓度增大而增大,在浓度为0.5 mg/mL时,鱼鳞抗氧化肽清除DPPH自由基能力达到Vc的81.1%;对超氧阴离子自由基清除率为98.97%.在胃肠消化前4 h内抗氧化活性较稳定,之后随时间延长抗氧化稳定性显著下降.[结论]在酶解草鱼鱼鳞的较佳工艺条件:温度60℃、料液比1:15、加酶量800 U/g、时间3 h下,碱性蛋白酶水解草鱼鱼鳞制备的抗氧化肽具有良好的抗氧化活性及稳定性.

Jian carp (cyprlnus carpio var Jian) fed for 90 days were compared with different iron content (146.1 mg/kg and 53.9 mg/kg) in their diet.Fish meats were collected and processed into surimi.After frozen storage at -20 ℃,the sample was collected at 0,1st,2nd,4th,6th week respectively.Indexes including Ca2+-ATPase activity (CA),total sulfhydryl (TSH) content,disulfide bonds (DB) content,protein surface hydrophobicity (PSH),and thiobarbituric acid (TBA) value were detected.Meanwhile,the activities of Cathepsin B/L of Jian carp surimi were detected by fluorescent synthesis of peptide substrate method.The results indicated that the initial CA and TSH content in suitable group was improved extremely significantly (p ＜ 0.01),while the initial DB content (0.01 ＜p ＜ 0.05),PSH and TBA value (p ＜ 0.01) was decreased at different degree.In terms of surimi quality during frozen storage,higher iron diet group delayed the decline of CA and TSH content,and increase PSH and DB content.After storing for 6 weeks,TBA value of Jian carp surimi increased 264％ in higher iron diet group and 143％ in low iron content group.During the frozen storage,CAT B/L activities in higher iron group were lower,and CAT L activity was decrased.In conclusion,the higher dietary iron supplement could retard the denaturation of Jian carp surimi protein during frozen storage,and reduce the residual of CAT B/L activities,and has the potential in stabilizing the quality of surimi during the frozen storage.

Start codon targeted polymorphism( SCoT) was used to analysis 32 cocksfoot( Dactylis glomerata) varieties( including cultivated and introduced varieties),to reveal the differences of genetic diversity in cultivated and introduced varieties and to provide a theoretical basis for breeding new varieties of cocksfoot. 1) Twenty-two primers were selected from 80 SCoT primers,and a total of 308 bands were amplified,of which 245( 79. 55%) were polymorphic: the average was 11. 14 per primer. 2) The average genetic distance of cultivated varieties was 0. 1242 while that of introduced varieties was 0. 1952. The introduced varieties had higher genetic distances than the cultivated ones at the level of polymorphism bands( NPB) and percentage of polymorphic bands( PPB). The gene diversity index( H) and Shannon index( I),indicated that the genetic diversity of cultivated varieties was lower than that of introduced varieties. 3) AMOVA analysis showed that the genetic variance within and between cultivated and introduced varieties was 83. 68% and 16. 32%,respectively and the main genetic variance was in the internal group. 4) The results of UPGMA clustering and PCoA analysis showed that the 32 cocksfoot varieties could be divided into six groups,the cultivated varieties were in group I while the introduced varieties were in the other five groups.

The studies on botanical and biological characteristics and cytology of local citrus variety'Ziyang xiangcheng'(Citrus junos Sieb.ex Tanaka) and the application effects of rootstock were carried out for many years.'Ziyang xiangcheng' had moderate vigor of growth,the leaves were narrow and long with a wide and long winged petioles.The average weight of fruit was 66g and oblate shape,with little rough and orange color peel,9 to 10 segments,and sour taste.There were seeds from 24 to 33 grains per fruit,the seed was bigger and polyembryonic with white cotyledon.The chromosome number of'Ziyang xiangcheng'was identified to be 2n = 18.The seedlings could blossom and set fruits since the 4th years.'Ziyang xiangcheng'has been used to be rootstock in our experiments for sweet orange,tangerine,lemon,tangor and Kumquat.The result showed that the cion plants had early-bearing period(the 3rd years) and high productivity with bigger fruits on the rootstock of'Ziyang xiangcheng'.The alkali resistance and growth vigor of 'Ziyang xiangchen' was significantly stronger than that of Poncirus triforliata in the purple alkaline soil(pH 7.2-8.4) in Sichuan basin.

Fruits of Robertson Navel orange, grown in 3 different ecological locations in Sichuan province, including south-subtropical Panzhihua, middle subtropical Jiang'an and north subtropical Ya-an were used as material for studying the effects of ecological conditions on the fruit quality. The results showed that the activities of Pectinmethylesterase (PE), Poly-galacturonase (PG) and Carboxymethycellulase (Cx) of the fruits grown in different habitats were different. The cell wall ultra-structure in Hongge, which included the mitochondrion, the erista and the middle lamella were clearly, showing fruit not ripening enough but the samples of Ya' an and Jiang' an showed obviously ripening characters: showing the decomposition of the mitochondrion and the middle lamella. The fruit SSC and soluble sugar were significantly different in different habitats. The correlations between PG, annual accumulated temperature, the January temperature and the annual mean temperature were negative at 0.05 levels, but to annual rainfalls were positive. The correlations of the SSC/Titrable acid ratio were positive to annual accumulated temperature, Annual temperature and January temperature at 0.01 levels, to sun hours at 0.05 levels, to annual rainfall significant at the 0.05 levels, negatively.

Experiment was conducted with fruit of Robertson Navel orange cultivar collected from 5 representative orchards located in 3 ecotype areas in Sichuan province for studying the organic acid accumulation and their related enzymes during the fruit development process, especially on the changes in activities of citrate synthase (CS), phosphoenolpyruvatecarboxylase (PEPC), cis-aconitase(ACO), isocitrate dehydrogenase (IDH) and malate dehydrogenase (MDH). The results showed that CS and PEPC played an important role in organic acid accumulation in fruit at the early stage of fruit development,while IDH was the key enzyme that cleaved citrate from 120 days after full bloom to the fruit ripening. During the process of fruit development, the activities of CS,MDH and mitochondrial cis-aconitase in fruit were similar in different habitats, whereas IDH activity changed significantly in different habitats. However, after 120 days after full bloom, the activities of PEPC and cytosolic cis-aconitase also changed significantly. It is suggested that the organic acid concentration in fruit grown in the different habitats was mainly determined by IDH, and partly by PEPC and cytosolic cis-aconitase, but not CS, MDH and mitochondrial cis-aconitase.

Navel orange(Citrus sinensis cvs.Robertson,Fengqi and Newhall) were chosen as testing materials in Zhoupo,Jingyan County.The studies of pectinmethylesterase(PE),polygalacturonase(PG),β-glycosidase and cellulase in navel orange during development of fruits were shown as follows.PE,PG and β-glycosidase could be tested at different stages.PE activity of pulp was greater than that of peel obviously,the changes of PE activities from Newhall and Robertson navel oranges had three peaks;PE activity of Newhall varied greatly than those of Robertson and Fengqi.PG activity was greater at maturity stage than at young and the expanding stages;PG activity in pulp was greater than in peel.β-glycosidase activity was tested firstly in fruits and the peak of β-glycosidase activity was at maturity stage.The peak of PE activity appeared earlier than those of PG and β-glycosidase.PE and PG were the major enzymes effected the development of navel orange fruits.

This study of Navel orange and Valencia orange is about the relationship between enzymes of Cx, PE, PG and fruit texture components including pectin, cellulose and lignin. The results show: The Cx, PE and PG enzyme exist during the development of orange fruit; different cultivars have a milestone about PE and PG while the orange is mature. While the reactivity of all three enzymes increases, the content of pectin and the hardness decreases. The activity of Cx largely infuluences the hemicellulose which is difficult to dissolved. Following the growth of the fruit, the lignin in the fruit decreases rapidly.

脐橙是世界上最主要的柑桔鲜食良种,深受世界各国消费者的喜爱[1].四川省先后主要引进和推广了华盛顿、罗伯生、朋娜、纽荷尔、奈维林娜等欧养脐橙以及少量清家、白柳、大三岛等日(本)系脐橙品种,由于多数柑桔产区温暖高湿寡日照,现有引进脐橙品种产量品质难以两全[2].

The activity changes of enzymes related to sucrose accumulation during “Robertson Navel” fruit development and their relationships with the sugar accumulation were studied. The results show that before 150 days after anthesis (DAA) and after 150 DAA, the key enzymes of sugar accumulation are sucrose phosphate synthase and sucrose synthase (synthetic direction) due their activities and sugar content are significant correlation, respectively. The sucrose synthase activity including synthetic direction and cleavage direction have a similar variance curve, and when the activities of sucrose phosphate synthase and sucrose synthase (synthetic direction) increase gradually, the sucrose synthase activity (cleavage direction) rises again correspondently, thus, sucrose synthase (cleavage direction) is important to sugar accumulation due, it adjusts fruit sink strength by regulating sucrose content in fruit.

研究了四川3个生态型区5个代表性果园中的脐橙果实蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性变化及其与果实糖积累的关系.结果表明:SPS是影响果实膨大期糖积累的重要酶,而成熟期的关键酶则是SS合成方向;在不同生境下,果实内SPS和SS分解方向活性差异不明显,而SS合成方向活性的差异则达到极显著水平,说明虽然SS分解方向和合成方向都通过调节果实库强而影响糖的运输和积累,但SS合成方向才是引起不同生境下脐橙果实含糖量差异的关键酶.