江南白鹅消化器官的早期生长发育特点及其相关性研究

为探究江南白鹅消化器官早期生长发育特点,通过饲养试验研究江南白鹅消化器官的生长发育规律及其与体重的相关关系,以期为江南白鹅及其他中型白鹅的饲料科学配制和科学饲养参考.结果 表明:①4周龄时,各消化器官的长度或重量与9周龄时比较,十二指肠、空肠和回肠的长度和重量均达80％以上,盲肠达69％,胃重量达63％,肝脏重量达56...     

Fusarium oxysporum对苗期大豆根部的致病性和侵染规律

Fusarium oxysporum对苗期大豆具有较强的致病作用。病原菌自伤口或直接侵入大豆幼苗根部的皮层组织,随着病原菌的侵入和扩展,细胞出现坏死,组织发生崩解,根部组织表现红褐色病斑。环境因素对病原菌的侵染时期和在大豆体内潜育时间的长短有着明显的影响。侵染时期主要受病原菌侵入前自身所处状态和寄主的影响,侵入后潜育时间的长短则受植株状态的影响。土壤环境条件直接影响着病原菌的侵入和寄主的抗病性,间接影响着病原菌在大豆植株体内的扩展和病症的表现。     

利用12C6+重离子辐射和尖孢镰刀菌毒素筛选杂交兰抗茎腐病突变体

为创建抗茎腐病杂交兰资源,本研究以玉女兰类原球茎为材料,采用¹²C⁶⁺重离子辐射技术结合尖孢镰刀菌(Fusarium oxysporum)粗毒素筛选抗茎腐病突变体。结果表明,经不同剂量¹²C⁶⁺重离子辐射后,玉女兰类原球茎的死亡率差异显著,辐射剂量为50 Gy时,死亡率为54.66%;尖孢镰刀菌粗毒素对玉女兰类原球茎存活率影响显著,当粗毒素滤液浓度为80%时,玉女兰类原球茎存活率为41.98%。采用逐步筛选法对经50 Gy¹²C⁶⁺辐射后的玉女兰类原球茎进行抗茎腐病筛选,获得14个抗性系类原球茎,筛选率为4.67%;对抗性系类原球茎进行分化、生根壮苗和移栽,获得3个抗性系Z50Gt₁、Z50Gt₂和Z50Gt₃。在含80%粗毒素滤液的培养基上抗性系类原球茎的超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性均高于对照,POD活性峰值比对照提高了867.67 U·g^-1·h^-1;丙二醛(MDA)含量呈现先高于对照,随着毒素胁迫时间的延长,转变为低于对照的趋势。对3个抗性系试管苗和小苗进行人工接种鉴定,结果表明,抗性系Z50Gt₂和Z50Gt₃的再生植株具有稳定的茎腐病抗性,2个抗病株系7个月大的盆栽植株病情指数分别为20.00%和19.33%,均为抗性级别。本研究结果为采用重离子辐射技术选育抗茎腐病杂交兰新品种奠定了基础。     

萝卜溶菌酶抑菌效果的初步研究

研究了萝卜溶菌酶对白色葡萄球菌，金黄色葡萄球菌，枯草杆等３种革兰氏阳性基本国策 和变形菌、大肠杆菌，鼠伤寒沙门氏杆菌，多杀巴斯德氏杆菌，雏白痢沙门氏菌，产气杆菌等６种革兰氏阴性菌及酿酒酵母，总状毛霉，黑根霉、黑曲霉、青霉等５种真菌的抑制效果，同时还研究了萝卜溶菌酶对白菜软腐病菌，柑橘溃疡病菌，番茄青枯病菌，水稻细条病菌，水稻白叶枯病菌及烟草青枯病菌等６种植物病原细菌的抑菌效果。实验证明：萝卜溶菌酶     

Trypsin enzyme activity during larval development of Litopenaeus vannamei (Boone) fed on live feeds

Larval stages of the Pacific white shrimp, Litopenaeus vannamei (Boone) were fed standard live diets of mixed microalgae from the first to the third protozoea (PZ1 to PZ3), followed by Artemia nauplii until post‐larvae 1 (PL1). Trypsin enzyme activity for each larval stage was determined using N‐α‐p‐toluenesulphonyl‐l ‐arginine methyl ester (TAME) as a substrate. Results were expressed as enzyme content to assess ontogenetic changes during larval development. Tissue trypsin content (IU µg^?1 DW for each larval stage) was significantly highest at the PZ1 stage and declined through subsequent stages to PL1. This contrasts with previously observed patterns of trypsin development in Litopenaeus setiferus (Linnaeus) and other penaeid genera, which exhibit a peak in trypsin activity at the third protozoea/first mysis (PZ3/M1) larval stage. Litopenaeus vannamei larvae transferred to a diet of Artemia at the beginning of the second protozoea (PZ2) stage were significantly heavier on reaching the first mysis stage (M1) than those fed algae, while survival was not significantly different between treatments. At both PZ2 and PZ3 stages, trypsin content in larvae feeding on Artemia was significantly lower than in those feeding on algae. The rapid decline in trypsin content from PZ1 and the flexible enzyme response from PZ2 suggest that L. vannamei is physiologically adapted to transfer to a more carnivorous diet during the mid‐protozoeal stages.     

A3α肽聚糖对凡纳对虾幼体生长及抗病毒感染力的影响

用含不同量的A3α肽聚糖(PG)(0.005%、0.01%、0.1%)的幼体饵料投喂凡纳对虾幼体,另在育苗水体中添加不同水平(0.005mg·mL-1、0.01mg·mL-1、0.05mg·mL-1)PG浸浴并以投喂不添加PG的幼体饵料的实验组作为对照,另设投喂活饵的实验组作参考,分别考察Z1-M1期、M1-PL1期、Z1-PL1期幼体的成活率,M1期、PL1期幼体体长,PL1期幼体体重,另外,PL1期仔虾经7d饲养后,检测体内酚氧化酶(PO)活性,并用白斑综合症病毒(WSSV)料投喂感染。结果显示:与投喂不添加PG幼体饵料组相比,在Z1-M1期,活饵组、0.01%PG添加量的幼体饵料组、0.005mg·mL-1PG的浸浴组幼体的成活率有极显著(P<0.01)提高,而在Z1-PL1、M1-PL1期,各实验组除0.05mg·mL-1浸浴组外均有极显著地(P<0.01)提高;各实验组除0.01mg·mL-1、0.05mg·mL-1PG浸浴组外,M1期幼体体长、PL1期幼体体重也有显著(P<0.01)增长,且各实验组PL1期幼体都有极显著(P<0.01)增长;各实验组仔虾PO活力均有极显著(P<0.01)提高;各实验组除0.1%PG添加量的幼体饵料组外,感染WSSV后仔虾的存活率有不同程度地提高。     

皖西白鹅不同时期卵巢肥大细胞的比较研究

应用组织化学甲苯胺蓝染液染色皖西白鹅不同时期卵巢的肥大细胞(MC)显微镜观察测量后,对数据进行统计和方差分析。结果表明:皖西白鹅产蛋期与就巢期MC的形态、大小及数量差异极显著(P<0.01),产蛋前与就巢期差异显著(P<0.05),而产蛋期与产蛋前差异不显著(P>0.05)。说明同种皖西白鹅的卵巢MC,在不同时期存在着差异性。     

食用菌苎麻骨培养物对活性艳红X-3B染料脱色研究

[目的]研究食用菌苎麻骨培养物对活性艳红X-3B染料的脱色效果。[方法]将香菇、平菇和金针菇3种常见食用菌株接种至苎麻骨培养基上培养,研究培养物对50 mg/L活性艳红X-3B溶液的降解脱色效果。[结果]香菇培养物处理3 h对染料溶液脱色率可达92.17%,平菇培养物处理3 h对其脱色率可达72.40%。此外,香菇培养物对该染料溶液具有很好的重复处理效果,但重复处理次数越多脱色效果越差。[结论]香菇和平菇的苎麻骨培养基培养物对活性艳红X-3B溶液具有较好的脱色效果。     

Dietary protein level and natural food management in the culture of blue (Litopenaeus stylirostris) and white shrimp (Litopenaeus vannamei) in microcosms

The effect of dietary protein level and natural food management on the production parameters of blue and white shrimp, as well as on water quality, was evaluated in a microcosms system (plastic pools simulating aquaculture ponds). Two experimental trials were carried out in the facilities of DICTUS, University of Sonora, Northwest México. Treatment with low protein diet (LP) consisted of a low protein input (diet with 250 g kg^?1 crude protein) through the culture period; treatment with high protein diet (HP) consisted of a high protein input (diet with 400 g kg^?1 crude protein) through the trial, and finally treatment VP consisted of an adjustment of protein input (diets with 250, 350 or 400 g kg^?1 crude protein), depending on the abundance of biota (zooplankton and benthos) in the system. Each species responded differently to the treatments. For blue shrimp, low protein input resulted in the lowest final body weight (12.9 ± 0.6 g) and biomass (696.0 g pool^?1). Survival and feed conversion ratio were similar in the three treatments. For white shrimp, the best growth, biomass and food conversion ratio were obtained in the low protein input treatment. Water quality parameters such as nitrate, ammonia and organic matter during the two trials, were better for LP and VP treatments. White shrimp seems to have lower protein requirements than blue shrimp. For the blue shrimp culture, adjusting protein input according to natural food abundance (zooplankton and benthos) in the system, seems to be advantageous because of the possibility of getting a production similar to that obtained with a high protein input through the farming period, but at lower feed cost, and with a lower environmental impact. It is concluded that a high protein input through the whole farming period is not the best feeding strategy for any of the two species.     

养殖曼氏无针乌贼白色卵膜营养成分分析及评价

测定分析并评价了养殖曼氏无针乌贼（ Sepiella maindroni）白色卵膜（WEM）的营养成分。结果表明,WEM （鲜样）中水分、粗灰分、粗蛋白和粗脂肪的质量分数分别为92.34％、1.76％、5.28％和0.34％。WEM（干样）中氨基酸（AA）总量为55.53％,其中必需氨基酸（EAA）总量为19.85％;必需氨基酸与非必需氨基酸（NEAA）的比值为65.6％,构成比例符合 FAO/ WHO 规定的优质蛋白质标准;鲜味氨基酸（ DTAA）总量为29.53％。WEM的第一限制性氨基酸为苯丙氨酸＋酪氨酸（Phe ＋ Tyr）,必需氨基酸指数（EAAI）为38.03。脂肪酸中多不饱和脂肪酸（PUFA）占19.21％。矿物质含量丰富,尤其以磷（P）质量分数最高（1423.2 mg·kg -1）。结果表明,WEM 营养组分较为全面,与野生黑色卵膜（BEM）的营养成分进行对比分析发现,在氨基酸组成、必需氨基酸和无机元素质量分数等方面存在差异,这种差异是否是导致白化受精卵孵化率降低的关键因素有待进一步研究。