三种生根剂对"广益"牛鞭草插穗生根的作用

本试验以NAA、ABT、IBA三种生根剂各200×10-6,100×10-6,80×10-6,60×10-6,40×10-6浓度对"广益"牛鞭草插穗处理5分钟,通过测定株平均生根数、株平均生根长度、最大根长及其分蘖情况,说明80×10-6的ABT、100×10-6的IBA、200×10-6的NAA能使牛鞭草插穗的生根数分别增加72%、318%、254%,根长分别增加103%、724%、548%,鲜根量分别增加88%、128%、88%。证明生根剂对牛鞭草插穗成活生根有促进作用,应在生产实践中推广运用。     

油桐无性系生产力判别评级与预测研究

根据选自福建、浙江等５个油桐主产省（区）７６个油桐优良单株无性系在金华试验点的生长表现，按照其中已测定含油率、产果量和其它性状的６５个油桐无性系样本，建立了生产力评级的Ｆｉｓｈｅｒ判别模型，该模型对分属Ⅰ、Ⅱ、Ⅲ、Ⅳ４个产油量水平的各无性系的回判正判率分别达到了１００％、１００％、８２％、１００％。进而应用该模型预测了未进行气干果含油率测定的其它１１个无性的生产力等级。据此，从７６个无性系中筛选出４４、４８、５４、５６号４个高产优良无性系。     

外源人绒毛膜促性腺激素诱导黑边石斑鱼排卵的研究

【目的】了解外源人绒毛膜促性腺激素(human chorionic gonadotropin,HCG)诱导黑边石斑鱼(Epinephelus fasciatus)排卵的影响。【方法】以成熟的黑边石斑鱼为研究对象,测量其体长、体质量和肥满度后,在2018年7—8月,使用HCG激素(剂量为200 IU/kg或500 IU/kg)注射分别对6尾雌鱼进行成熟诱导。【结果】在200 IU/kg HCG处理中,注射24 h前有5尾雌鱼的卵母细胞处于第三次卵黄球前期阶段;注射48 h后2尾雌鱼出现核移动卵母细胞,1尾雌鱼的卵母细胞为第三次卵黄球后期阶段;注射60 h后1尾雌鱼出现排卵现象,其余5尾雌鱼均为第三次卵黄球后期阶段。在200 IU/kg HCG处理的排卵个体中,注射时其卵母细胞直径为477.0 μm,注射后60 h卵母细胞的直径增加至624.4 μm。此外,经催产、排卵、受精和孵化后共获得总卵数16 906粒,受精率为68.7%,孵化率为43.0%。而500 IU/kg HCG处理的黑边石斑鱼排卵失败。【结论】使用剂量为200 IU/kg的外源HCG激素可诱导黑边石斑鱼成熟且排卵,但为了提高排卵率、受精率和孵化率,其注射剂量和效应时间还需要进一步调节。     

5种石斑鱼遗传差异的RAPD分析

运用随机扩增多态性DNA（random amplified polymorphic DNA,RAPD）技术对鞍带石斑鱼（Epinephelus lanceolatus）、驼背鲈（Cromileptes altivelis）、棕点石斑鱼（E.fuscoguttatus）、斜带石斑鱼（E.coioides）和鲑点石斑鱼（E.fario）的遗传多样性及系统发生进行了研究。从120个RAPD随机引物中筛选出扩增效果好的引物19个,分别用于5种石斑鱼基因组DNA的扩增。结果显示,5种石斑鱼平均多态性位点比率（P）分别为64.23%,72.61%,60.34%,69.97%,73.94%;个体间平均遗传相似系数（S）分别为0.8238,0.8110,0.8345,0.8277,0.8064;平均遗传距离（D）分别为0.1762,0.1890,0.1655,0.1723,0.1936;平均Nei基因多样性指数（H）分别为0.1189,0.1364,0.1028,0.1439,0.1648;平均Shannon信息指数（Hi）分别为0.1801,0.1992,0.1530,0.2100,0.2434。5个种间的遗传距离（Dxy）在0.3964～0.6085之间。     

荧光定量PCR法检测点带石斑鱼神经坏死病毒研究

根据己公布的神经坏死病毒全基因序列,应用引物设计软件依据Gene Bank所收录的各种石斑鱼神经坏死病毒RNA2基因组全序列选择保守区域,根据Taqman探针引物设计原则,设计Taq Man探针及其引物。采用Taq Man探针技术,并且将假病毒技术构建的含有神经坏死病毒RNA2基因组的MS2噬菌体假病毒作为阳性质控品,建立Taq Man探针检测点带石斑鱼神经坏死病毒的荧光定量PCR方法,拟合标准曲线,能够在病毒检测中进行绝对定量,能检测到10个病毒拷贝模板数,在临床检测中得到很好运用。本研究建立实时荧光定量RT-PCR,有助于日常检验工作,为鱼类神经坏死病毒的筛选和监测提供基础,有助于控制神经坏死病的疫情传播。     

模糊综合评价法判断重庆花椒种植区土壤肥力水平

为揭示重庆花椒地土壤质量状况及空间特征,采集重庆主要花椒区45个土壤样品,测定pH值、容重、有机质、有效磷、碱解氮、速效钾、有效铜、有效锌、有效铁、有效锰、有效硼、有效钼、有效硫共13个指标,采用模糊综合评价法对土壤质量进行综合评价,并利用半变异函数分析各指标空间变异特征。结果表明:各养分指标变异系数范围为14.8%～171.4%,该区域养分含量分布很不均衡;有效磷、有效铁、有效硼、有效硫的空间相关性较弱,主要受随机性因素影响;有效锌和有效铁的隶属度最高,其值分别为0.89、0.91,有效硼和有机质的隶属度较低,其值为0.15、0.34,说明花椒地有效锌和有效铁含量较丰富,但有效铁和有机质含量较缺乏;整体上该区中等肥力水平占51.1%,中等偏上肥力水平占42.2%,中等偏下肥力水平占6.7%,土壤肥力综合指数的在空间上呈现球状半变异函数,拟合程度极高。     

斜带石斑鱼病原菌(哈维氏弧菌)的分离与鉴定

从患病斜带石斑鱼 (Epinepheluscoioides)肝脏组织分离到EcGY0 2 0 4 0 1菌株 ,经人工感染、回归感染实验证实为致病菌。通过API系统和菌体常规形态特征、培养特性和生理生化反应指标测定以及 16SrRNA测序分析等综合鉴定 ,Ec GY0 2 0 4 0 1菌株为弧菌属哈维氏弧菌 (Vibrioharveyi) ,其半致死剂量LD50 为 2 .7× 10 6CFU/g鱼体重。药敏试验结果表明 ,EcGY0 2 0 4 0 1菌株对利福平、四环素、喹诺酮类及头孢曲松等抗生素较为敏感     

在循环养殖系统中添加微生态制剂去除氨氮和亚硝酸氮的试验

利用活菌制剂,以闭路内循环方式净化水质,养殖点带石斑鱼。试验结果表明:3种活菌制剂对NH4 -N的降解率分别为:NMX菌39.0%,科恩菌30.5%,EM菌20.4%;对NO2--N的降解率分别为:NMX菌45.7%,EM菌40.4%,科恩菌13.6%。活菌制剂不仅能调节水质,而且还能促进养殖个体的生长,提高饵料转化率,NMX菌、科恩菌和EM菌试验组日增重分别为5.5 g/尾、5.1 g/尾、4.9 g/尾,而对照组为3.9 g/尾;相应饵料系数分别是1.00、1.02、1.02,对照组为1.06。     

Alternative vegetable lipid sources in diets for grouper, Epinephelus coioides (Hamilton): effects on growth, and muscle and liver fatty acid composition

The aim of this study was to investigate the effects of different oils on growth performance and lipid metabolism of the grouper, Epinephelus coioides. Five experimental fish meal‐based isonitrogenous and isolipidic diets were formulated containing either 5.5%‐added fish oil (FO), soybean oil (SBO), corn oil (CO), sunflower oil (SFO) or peanut oil (PO). Each diet was fed to triplicate groups of 20 fish (initial body weight 13.2±0.02 g) grown in seawater at 28.0–30.5 °C for 8 weeks. Fish were fed twice a day to visual satiety. No significant differences in the survival, weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio or hepatosomatic index were found between fish fed the FO or vegetable oils (VO) diets. Dietary lipid sources did not affect whole‐body composition among grouper fed the various diets. Muscle of fish fed the FO diet had significantly higher levels of 14:0, 16:0, 16:1n‐7, 20:5n‐3[eicosapentaenoic acid (EPA)] and docosahexaenoic acid (DHA)+EPA (except for PO fed fish) compared with those of fish fed VO diets. However, the levels of 18:1n‐9, 18:2n‐6 and DHA/EPA ratios in the muscle of fish fed FO diet were significantly lower than those of fish fed the VO diets. The liver of fish fed the FO diet had significantly higher levels of 18:0, 20:5n‐3, 22:6n‐3, n‐3 highly unsaturated fatty acids and DHA+EPA than those of fish fed the VO diets, whereas increases in 18:1n‐9, 18:2n‐6 and mono‐unsaturated fatty acid levels were observed in the liver of fish fed the VO diets.     

Optimal dietary protein requirement of grouper Epinephelus coioides juveniles fed isoenergetic diets in floating net cages

An experiment to determine the optimal protein requirement of grouper Epinephelus coioides juveniles was conducted in floating net cages (1.5 m × 1 m × 1.5 m). Six isoenergetic fishmeal–casein‐based experimental diets containing 350–600 g kg^?1 crude protein (CP) were fed to triplicate groups of 20 fish (10.7 ± 0.2 g) for 56 days. Weight gain (WG) and specific growth rate (SGR) increased with increasing dietary protein level from 350 to 450 g kg^?1 and then plateaued above these levels. Feed intake (FI) showed no significant difference among fish fed more than 350 g kg^?1 CP. Lowest feed conversion ratio (FCR) was found for fish fed 500 g kg^?1 CP but this was not significantly different from that of fish fed the 450 and 600 g kg^?1 CP. Lowest protein efficiency ratio (PER) was found for fish fed 550 and 600 g kg^?1 CP. Fish fed the 600 g kg^?1 CP had the highest body protein and moisture contents but the lowest body lipid content. Body ash content was unaffected by protein level for fish fed >400 g kg^?1 CP. Dietary protein level had no significant effect on hepatosomatic index (HSI). Fish fed the 350 g kg^?1 CP had significantly lower condition factor (CF) and viscerosomatic index (VSI). Based on broken‐line regression analysis of SGR the optimal dietary protein requirement for E. coioides juveniles was determined to be close to 480 g kg^?1.