【Objective】 This study analyzed the differences of nutritional components of Coilia nasus under high and conventional cultural density levels and evaluated whether young C. nasus fish cultured under high density was oppressed by the crowded environment.【Method】 C. nasus young fish（0 + age） were cultured at high density（108 240 ind/hm~2） and conventional density（62 505 ind/hm~2） in pond.Contents of moisture, crude ash, crude protein and crude fat in fresh fish samples and contents of common amino acids and fatty acids in dry fish samples were determined.Then, the nutritional quality was evaluated by amino acid score（AAS）,chemical score（CS）,essential amino acid index（EAAI） and the ratio of branched chain amino acids to aromatic amino acids（F value）.【Result】 The crude protein content（14.07%） and crude fat content（2.50%） of high density were significantly lower than that of conventional density（15.16% and 3.97%）（P＜0.05）.No significant difference was found in moisture and crude ash contents between the two levels（P＞0.05）.The arginine and tryptophan contents of high density were significantly higher than that of conventional density（P＜0.05）,while the histidine content of high density was significantly lower than that of conventional density（P＜0.05）. There was no significant difference（P＞0.05） in contents of other 15 amino acids.There was no significant difference in total common amino acid（TAA）,total essential amino acid（EAA）,total half-essential amino acid（HEAA）,total non-essential amino acid（NEAA） and total delicious amino acid（DAA） contents as well as EAA/TAA,EAA/NEAA and DAA/TAA specific values in dry samples between the two levels（P＞0.05）.The EAAI and F value of the two levels were very close.Among the detected 28 fatty acids, there were significant differences in contents of 22 kinds of fatty acids（P＜0.05）.Amongst major fatty acids, contents of C18:1n9c, C16:1,C18:3n3,C20:2 and C20:5n3 of high density were significantly lower than that of conventional density（P＜0.05）,while contents of C18:0,C22:2,C20:4n6,C22:5n3 and C22:6n3 of high density were significantly higher than that of conventional density（P＜0.05）.The total saturated lipid acid（SFA）（34.49%）,total polyunsaturated fatty acids（PUFA）（30.22%） and n3PUFA/n6PUFA（2.66） of high density were significantly higher than that of conventional density（32.65%, 28.71% and 2.55）（P＜0.05）,while the content of total monounsaturated fatty acids（MUFA）（35.29%） of high density was significantly lower than that of conventional density（38.64%）（P＜0.05）.【Conclusion】 Although high density culture in pond did not decrease protein quality of C. nasus young fish, it significantly decreased crude protein, crude fat and MUFA and significantly increased PUFA and n3PUFA/n6PUFA.It is indicated that C. nasus young fish cultured under high density level was stressed by overcrowding.The suggested stocking density of C. nasus young fish in pond is no more than 108 240 ind/hm~2.

自2009年起柑橘黑点病逐渐成为上海地区影响柑橘果实商品价值的最主要病害,严重制约上海市柑橘产业的效益.为了解该病的田间流行动态以及病害发生与降雨量的关系,2010年-2018年连续9年进行了病害发生动态调查和分析.结果表明,上海地区6月上旬至8月下旬是果实感病期,其中,6月中旬至7月中旬为发病高峰期;雨水是黑点病发生的必要条件,果实生长期不同阶段的降雨参数,尤其是6月下旬的降雨量与病情指数密切相关.本文以病情发展的3个时间节点(7月15日、8月15日和9月10日)的病情指数为因变量,以这3个时间点之前各旬的降雨量、降雨日为自变量筛选变量建立了多元线性回归方程,根据分析结果,采用6月下旬的降雨量等气象因子建立的多元线性回归方程,可以比较准确地预测7、8月中旬和9月10日即病害发展稳定期的田间病情.

美洲鲥(Alosa sapidissima)俗称美国鲥鱼,属于鲱科、鲥亚科、西鲱属,美洲鲥与中国鲥有很多相似点,为溯河繁殖的洄游性鱼,体形相近且肉质鲜美.目前,我国美洲鲥养殖面积日益扩大,每年投入的苗种数量在300万～350万尾,养殖前景看好.上海市水产研究所于1998年率先引进美洲鲥受精卵,开始人工繁殖及养殖技术研究,经过多年相关关键技术参数的优化,形成了一整套美洲鲥人工繁育及养殖的工艺流程和技术方案,实现了规模化生产.

为掌握美洲鲥(Alosa sapidissima)发育早期内源性营养阶段的脂肪酸变化及利用规律,采用生化分析手段,检测和分析美洲鲥的胚胎(原肠期)、0日龄和4日龄仔鱼(摄食前)的粗脂肪含量和脂肪酸组成.结果显示,随着个体发育,美洲鲥内源性营养阶段的水分含量显著降低、鲜质量的粗脂肪含量显著上升、干物质的粗脂肪含量微弱升高,而单个个体的粗脂肪含量显著下降,数值从胚胎的60.04μg下降到4日龄仔鱼的41.91μg.胚胎孵化破膜期间,C18:1 n9c和C22:6n3(DHA)大幅减少.仔鱼出膜后到开口摄食前,对脂肪酸的利用优先顺序为n6PUFA>MUFA>SFA>n3PUFA,C18:2n6c、C18:3n6、C16:0和C18:1 n9c被先期利用,而对n3PUFA的利用极低(特别是EPA+DHA).研究表明,美洲鲥胚胎孵化出膜期间,EPA被先期暂存,而DHA被大量利用;仔鱼出膜后,n3PUFA被优先保存,特别是EPA+DHA.因此,建议美洲鲥亲本产前培育和产卵期间,增加投喂富含n3PUFA(特别是DHA)的饲料,以增加其受精卵营养储备,提高美洲鲥开口前仔鱼的成活率.

[目的]研究池塘高密度培育刀鲚当年鱼种(0+龄)的脂类营养状况及脂肪酸组成的变化规律,评估高密度养殖刀鲚幼鱼有否受到环境拥挤压迫.[方法]采用池塘高密度(7216 ind/667 m2)模式养殖刀鲚幼鱼,检测分析刀鲚0+龄幼鱼各阶段(7-11月)的鱼体脂肪酸组成及含量.[结果]池塘高密度培育刀鲚0+龄幼鱼鱼体的水分含量随着生长呈现直线下降趋势,数值从7月的82.27％显著下降到11月的76.17％;培育早期(7月26日至8月7日),鱼体干重的总脂含量略有下降,培育中期(8月7日至10月5日)鱼体脂肪迅速富集,然而,到培育后期(10月5日至11月1日),由于饵料竞争,鱼体脂肪积累速度减缓.刀鲚各阶段幼鱼鱼体脂肪酸含量排前三的是C16:0、C18:1n9c和C16:1,百分含量范围分别为21.21％～29.76％、23.56％～28.90％和8.71％～14.29％.除了 7月外,C16:0和C16:1的百分含量随生长均呈现显著下降.随着刀鲚幼鱼的生长,C18:0百分含量随生长呈现先上升后下降趋势(P＜0.05),最高点(7.62％～7.76％)出现在8-9月份;而刀鲚幼鱼的C22:6n3(DHA)、C20:5n3(EPA)、ΣPUPA以及Σn3PUPA的含量随生长呈现先下降后上升的趋势(P＜0.05),最低值均出现在9月,最高值均出现在11月.其Σn3PUPA/Σn6PUPA比率9月最低(3.58),11月最高(5.35),这符合刀鲚幼鱼从淡水到海水的洄游规律.高密度培育后期(10月5日至11月1日),随个体生长,拥挤胁迫更加明显,刀鲚幼鱼为应对拥挤胁迫需要消耗更多MUFA,特别是C18:1n9,导致刀鲚鱼种鱼体的ΣMUFA和C18:1n9c含量均分别从10月的44.42％和28.90％迅速下降到11月的35.29％和23.56％.[结论]池塘高密度培育的刀鲚当年鱼种可能已经受到环境拥挤胁迫.建议适当降低刀鲚当年鱼种的池塘培育密度.

衢州素有"中国椪柑之乡"、"中国胡柚之乡"等称号,柑橘是衢州种植面积最大、产量最多的水果.2018年,柑橘种植面积占全市水果总面积的76.13％,产量占水果总量的67.38％,柑橘产业对衢州水果和农业产业的发展有直接的影响.柑橘产业也是衢州农村经济的重要组成部分,衢州市所辖6个县市区均有柑橘分布,柑橘产业是全市农业的支柱产业之一,其发展状况直接关系到农村发展和农民增收.

[目的]探讨不同树体载果量水平对初果期红桔、美国糖桔、春见、红美人和胡柚等5个晚熟杂柑品种风味品质及果实质地的影响,以期为各品种初果期最适宜树体载果量区间设定和鲜食品质提升提供理论依据.[方法]2019年,以生长势基本一致、4年生的各品种挂果树为材料,在设施栽培条件下设定单一载果量处理,以果实可溶性固形物(TSS)含量与可滴定酸(TA)含量比值变化趋势为主要指标,判断各品种果实成熟进程并选定相对适宜的采收期;2020年在此基础上设定高、低载果量2个处理,分别测定各品种成熟期果实TSS和TA含量,果肉和果皮中可溶性糖、有机酸组分及含量,以及果实质地相关参数,并对载果量与各果实品质指标进行相关分析.[结果]适宜的低载果量下,初果期红桔果肉中蔗糖、果糖、葡萄糖和柠檬酸含量不同程度提升;春见果肉中蔗糖、果糖和葡萄糖含量提升的同时柠檬酸含量下降、苹果酸含量提升;而红美人在低载果量下果肉中蔗糖含量下降、葡萄糖含量提升的同时苹果酸含量下降,各品种果肉中糖酸比例不同程度发生改变;至采收时,高载果量处理下红桔TSS/TA比值较低载果量降低12.7％;春见和美国糖桔2个品种TSS/TA比值较低载果量分别增加7.3％和7.1％.在红桔上,树体载果量水平与果皮硬度呈极显著相关(P<0.01,下同),与果皮韧性和果肉有机酸含量呈显著相关(P<0.05,下同);在胡柚上,载果量与果皮韧性呈极显著相关,与果皮可溶性糖含量呈显著相关;在红美人上,载果量与果皮硬度呈显著相关,与果皮可溶性糖含量呈极显著相关;在春见上,载果量与果皮有机酸含量呈显著相关,与果肉可溶性糖含量呈极显著相关;在美国糖桔上,载果量与果肉硬度呈极显著相关,与果肉韧性呈显著相关;但所有供试品种果肉化渣性指标,即果肉紧实度和囊衣硬度与树体载果量水平均未表现出明显相关性.[结论]初果期红桔、红美人和胡柚3个供试品种在较低载果量下,TSS/TA比值略高、最终采收时综合风味更好,春见和美国糖桔2个品种则在较高载果量下TSS/TA比值略高,综合风味更佳.该结果可为不同品种柑橘控产提质技术的进一步完善提供数据支持和参考.

[目的]研究不同养殖水温对金钱鱼幼鱼呼吸和代谢活动规律的影响,为其适宜养殖水温的确定提供依据.[方法]采用静水密闭式方法,在盐度5条件下,以体质量(8.84±0.32) g/尾的金钱鱼幼鱼为试验对象,设置15,20,25,30和35℃不同养殖水温处理,测算并分析不同处理金钱鱼幼鱼的耗氧率、排氨率、代谢率、排泄率、氧氮比、呼吸温度系数(Q10值)、排泄Q10值、窒息点及其变化规律,以明确金钱鱼幼鱼适宜的养殖水温.[结果]养殖水温为15～30℃时,金钱鱼幼鱼的耗氧率、排氨率、代谢率和排泄率均随着水温的升高而增加,在30℃时达到峰值,分别为0.46 mg/(g·h)、3.81μg/(g·h)、6.29 J/(g·h)和0.09 J/(g·h),35℃时均开始下降.在15～35℃养殖水温内,金钱鱼幼鱼窒息点随着水温上升而升高,氧氮比为71.76～261.04;呼吸Q10值平均为2.50,20～25℃的呼吸Q10值为1.22;排泄Q10平均为2.23,25～30℃养殖水温的排泄Q10值为1.10.[结论]盐度5条件下,金钱鱼幼鱼主要由碳水化合物和脂肪提供能量,15～30℃为其适宜养殖水温,其中最适养殖水温为20～30℃.

研究不同激活盐度(5,10,15,20,25,30和35)对3个盐度(20,25和30)培育下金钱鱼精子激烈运动和寿命的影响.在金钱鱼亲本升盐过程中,分别在亲本培育盐度为20,25和30时挑选健康成熟的雄性金钱鱼亲本进行人工采精,再用不同盐度海水进行激活.结果 显示,金钱鱼雄鱼亲本在盐度20,25和30培育下,激活盐度为5和10时,其精子均不能被激活;在激活盐度为15～35范围内,随着激活盐度的升高,3个盐度培育下金钱鱼精子活力均呈现出先增强后减弱的趋势.研究表明,在pH为7.8～8.0时,金钱鱼雄鱼亲本最佳培育盐度范围为25～30,在pH为7.9±0.2时,精子最佳激活盐度范围为20～25.

"美国糖橘"为美国杂柑品种,近几年在上海市引进试种,其种植表现为糖度高、耐贮性好、抗寒抗病能力强、丰产性好等,适宜在上海市推广种植.为促进"美国糖橘"在上海市进一步推广种植,现对其在上海市的引种表现及栽培技术要点进行总结介绍,以供实际生产参考.

为明确上海地区'红美人'柑橘的病毒种类,2020年4月在崇明、金山、奉贤、嘉定、闵行和浦东采集疑似病毒感染的叶片样品11份,采用小RNA深度测序技术结合RT-PCR对不同来源的混合样品进行病毒种类鉴定.结果 表明,样品中含有柑橘衰退病毒Citrus tristeza virus (CTV)、柑橘黄化脉明病毒Citrus yellow vein clearing virus(CYVCV)、柑橘树皮裂纹类病毒Citrus bark cracking viroid(CBCVd)和柑橘类病毒Ⅴ Citrus viroid Ⅴ(CVd-Ⅴ).同时发现,上海地区'红美人'柑橘病毒复合侵染现象普遍.基于CTV和CYVCV的CP全长基因及CBCVd和CVd-Ⅴ全基因组序列系统进化分析结果表明:除了CYVCV的分离物与地理来源具有明显的相关性外,其余病毒及类病毒均没有严格的地域相关性.研究结果为开展'红美人'柑橘种苗病毒检测及病毒病的防治奠定基础.

为验证28％波尔多液悬浮剂(佳铜)、自配波尔多液和77％氢氧化铜可湿性粉剂对柑橘树脂病(黑点病)的防效,特进行了相关试验.结果 表明,28％波尔多液悬浮剂(佳铜)、自制波尔多液、77％氢氧化铜可湿性粉剂对柑橘黑点病均有较好的防效,其中以28％波尔多液悬浮剂(佳铜)100倍液和自制波尔多液对柑橘黑点病的防效较好,防效可达90％以上.

为筛选出防治柑橘黑点病的高效低毒药剂,特开展了6种杀菌剂对柑橘黑点病的防效对比试验.结果表明,77％硫酸铜钙可湿性粉剂(多宁)500倍液和77％硫酸铜钙可湿性粉剂(惠可谱)500倍液于柑橘第2次生理落果期开始施药,每隔20 d左右喷施1次,连续喷施3次,即可较好地控制柑橘黑点病的发生,至柑橘果实转色时,对柑橘黑点病的防效可达80％以上,且对柑橘无药害,对环境安全.

为筛选出防治柑橘树上棉大造桥虫的高效低毒生物药剂,特开展了32000 IU/mg苏云金杆菌WP和5％除虫菊素EC两种生物药剂对棉大造桥虫的防治效果对比试验.结果表明,32000 IU/mg苏云金杆菌WP和5％除虫菊素EC在施药后1 d对棉大造桥虫均无明显的控制作用;施药后7 d,32000 IU/mg苏云金杆菌WP 400倍液、5％除虫菊素EC 800倍液对棉大造桥虫的防治效果均可达到常规化学药剂对棉大造桥虫的防治效果,防效在90％以上,且对柑橘无药害,对环境安全.

Delayed harvesting technology is believed to improve the citrus fruit flavor, but improper tree fruit load under delayed harvest might cause puffiness and reduce fruit quality. In order to find out an optimum tree fruit load level to obtain better flavor quality as well as reduce puffiness in delayed-harvest citrus under protected cultivation, experiments were conducted in the present study between 2019 and 2020 to determine the effect of different fruit loads and fruit-bearing per single branch on the soluble sugars and organic acids metabolism in the peel and flesh, the anatomical structure of the matured fruit peel, and fruit texture-related indexes. The results suggested significant negative correlations between leaf N level and flesh sucrose and glucose contents, and between branch P level and flesh citric acid contents; no significant correlation between NPK levels and flesh texture; relatively lower leaf N and branch P under relatively higher load can increase flesh sucrose and glucose accumulation and slow down citric acid degradation to the greater extent, thus optimizing the sugar/acid ratio of fruits during delayed harvest. The lignification of parenchyma cells closely around peel secretory cavities due to ascorbic acid deficiency might be the primary cause for puffiness under low-load treatments.

柑橘(Citrus L.)属芸香科柑橘族柑橘亚族植物,为热带、亚热带多年生常绿果树,性喜温暖湿润气候,较耐热,不耐低温,但其耐寒性较柚、酸橙、甜橙稍强.柑橘用作经济栽培的主要是柑橘属、枳属和金柑属.其中,柑橘属主要分布在北纬35°以南的区域,柑橘的主栽品种大多来自该属.

采用软骨—硬骨双染色技术于体视镜下观察金钱鱼1～45日龄仔稚鱼脊柱、腹鳍、臀鳍等附肢骨骼的早期发育.结果显示,1～8日龄金钱鱼仔鱼脊索为无分节的圆锥体,11日龄髓弓和脉弓的出现标志着脊柱发育开始,28日龄出现分节的硬骨环,38日龄脊柱形成22～24节椎骨.所有附肢支鳍骨发育的顺序为胸鳍、腹鳍、尾鳍、臀鳍和背鳍.胸鳍在5日龄时形成胸鳍支鳍骨,38日龄上匙骨和肩带骨化;腹鳍在5日龄时出现腹鳍支鳍骨,33日龄时腹鳍支鳍骨原基硬骨化完成;尾鳍的尾下骨最早出现在11日龄,15日龄脊索末端向上弯曲,41日龄尾鳍骨化完成;臀鳍在13日龄时排泄孔与尾下骨之间出现6根软骨质的支鳍骨,22日龄时臀鳍前4根锐化臀刺,38日龄时臀鳍开始骨化;背鳍在13日龄时形成9枚软骨质的支鳍骨,21日龄背鳍前10～11根鳍条锐化成背棘,33日龄背鳍支鳍骨和鳍条相继开始硬骨骨化.在温度25.5～29.1℃,盐度由25逐渐降至1.7的养殖条件下,15日龄金钱鱼尾索上翘,主动捕食和运动能力增强,由仔鱼期转入稚鱼期;20日龄时开始出现栉鳞,可以逐渐盐度淡化;鱼棘出现后,苗种生产过程中应注意被刺伤.第1背棘为倒棘、臀棘的数量和栉鳞的出现是金钱鱼科在鲈形目分类划分的显著判断标志.金钱鱼仔稚鱼骨骼发育研究结果对其早期发育环境适应、生产操作和分类鉴定有重要作用.

In order to investigate the adaptability of Alosa sapidissima to high temperature stress, they were placed under three water temperature gradients (24 ℃, 28 ℃, 30 ℃) for 96 h, and the changes of antioxidant enzyme as well as non-specific immune enzyme activities in their liver and serum were studied at different time (0, 3, 6, 12, 24, 48, 96 h) under different water temperatures. The results showed that in the liver, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the 28 ℃ and 30 ℃ groups increased over time, and the malondialdehyde (MDA) content increased and then decreased with time, while there were no significant changes in the 24 ℃ group; the activities of SOD and CAT at 48 and 96 h were significantly higher than those in the 24 ℃ group (P＜0.05), and the GSH-Px activity and MDA content in the 30 ℃ group at 96 h were significantly higher than those in the other two groups (P＜0.05). In the serum, SOD activity and MDA content in the 30 ℃ group showed changes that increased first, then decreased, and then increased with time. The SOD activity and MDA content in the 30 ℃ group at 96 h were significantly higher than those in the 24 ℃ and 28 ℃ groups (P＜0.05). The 24 ℃ and 28 ℃ groups remained basically stable. The CAT and GSH-Px activities in the 28 ℃ group at 48 h showed an increasing trend with time, and were significantly greater than the other two groups (P＜0.05), while the CAT and GSH-Px activities in the 30 ℃ group showed a decreasing trend with time, and at 24-96 h, it was significantly smaller than the other two groups (P＜0.05), and the 24 ℃ group remained basically stable. Under the high temperature stress, the alkaline phosphatase (AKP) and acid phosphatase (ACP) activities of liver in the 28 ℃ and 30 ℃ groups decreased with time (P＜0.05), while it was basically remained stable in the 24 ℃ group; the AKP and ACP activities at 48 and 96 h were significantly smaller than those in the 24 ℃ group (P＜0.05). The activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the 30 ℃ group increased with time, and the AST activity at 96 h and the ALT activity at 48 h were significantly higher than those in the 24 ℃ group (P＜0.05); the AST activity in the 28 ℃ group increased with time, and was significantly higher at 96 h than that in the 24 ℃ group (P＜0.05), while the ALT activity increased first and then decreased with time. The above results show that high temperature stress has a significant impact on the antioxidant and non-specific immune enzyme activities of A. sapidissima, causing certain damage to its liver. Therefore, in the process of practical production and industrial aquaculture, it is necessary to avoid high temperature stress response from A. sapidissima, and recommend that the breeding temperature is controlled below 28 ℃.

为提升温州蜜柑可溶性固形物近红外光谱无损检测的精确度,对适合温州蜜柑可溶性固形物无损检测的近红外光谱进行了研究.结果表明,利用间隔偏最小二乘法,建立了温州蜜柑可溶性固形物与近红外光谱模型之间的关系,选出可溶性固形物的显著特征波段为890～918 nm,备选特征波段为830～858 nm、860～888 nm、650～688 nm.组合这些波段再次建模,可大大提高模型的预测能力,模型的拟合优度高达0.9040,交互验证均方根误差降到0.5046°Birx.

为研究高锰酸钾、硫酸铜和次氯酸钠对双叉薮枝虫水母的抑制杀灭效果,在水温(28.8±0.7)℃、盐度为(7.4±0.7)的条件下,分别进行了不同浓度高锰酸钾、硫酸铜和次氯酸钠对双叉薮枝虫水母作用3h和24 h后致死试验.结果 显示:当高锰酸钾浓度为2.0 mg/L时,3h后双叉薮枝虫水母平均成活率为80.0％,24 h后成活率为40.0％,当高锰酸钾浓度为2.9 mg/L时,3h后平均成活率为43.3％,24 h后平均成活率为0％;当硫酸铜浓度为0.3 mg/L时,3h后平均成活率约为100％,24 h后平均成活率为56.7％,当硫酸铜浓度为0.6 mg/L时,3h后平均成活率约为63.3％,24 h后平均成活率为0％;260 mg/L次氯酸钠浓度作用3h后,双叉薮枝虫水母成活率仍然有93.3％,但当104 mg/L次氯酸钠浓度作用24 h后,成活率迅速降为36.7％.综合比较,硫酸铜终浓度为0.6 mg/L且作用24 h抑制杀灭水母效果最佳,生产上药物作用24 h后结合池底吸污操作,抑制去除育苗水体中水母效果好.本研究对培育鱼苗过程中如何抑制去除双叉薮枝虫水母具有一定指导意义.