两种微生物菌剂不同灌根次数对天薯13号疮痂病防效试验

马铃薯疮痂病是影响天水地区马铃薯产量和商品属性最主要的土传病害.为防治该病发发生,通过前期试验选取格兰克和菌动力,现设置两种微生物菌剂进行不同次数灌根对天薯13号防效试验.结果表明,所有处理较对照均能提高长势、产量,且能有效降低疮痂病的发生,各处理对疮痂病的防效为44.8%～88.2%,较对照增产170.5kg/hm2^～6938.2kg/hm2^。格兰克灌根两次和菌动力灌根一次疮痂病防效较好,分别为88.4%和78.7%,较对照增产4683.3kg/hm2^和6938.2kg/hm2^。     

基于ANSYS对振动果树枝干“Y”型响应的研究

以机械振动采收果树为研究对象,利用ANSYS Workbench软件对机械振动采收果树枝干进行动力学研究。通过Pro/E 5.0参数化方法建立果树枝干三维实体模型,将模型简化处理后导入ANSYS Workbench中进行仿真分析[1],对果树枝干进行10阶模态分析,得到果树枝干的固有频率和振型;对其进行谐响应分析,计算出果树枝干产生共振的频率、共振幅值和共振幅度最大的位置。进行室内冲击试验,找到共振频率,与有限元分析结果进行比较,表明有限元分析法可以为撞击式收获机的优化和设计提供理论依据。     

预吸胀处理对提高黄瓜种子活力和抗冷能力的影响

预吸胀处理明显提高了黄瓜种子活力、萌发率和抗冷能力。其机理为改善了膜的修复作用和种子内部生理代谢过程，表现在物质渗漏和膜脂过氧化作用下降以及呼吸强度、ＴＴＣ还原力增强等方面。     

生态营养学理论在畜禽养殖业中的应用

随着养殖业的发展，畜禽养殖场和养殖规模不断增加和扩大，畜禽生产的排泄物以及由畜禽饲料带来的有毒有害残留对生态环境和人类健康构成了极大的威胁，严重影响了养殖业的发展。为了更好地保护生态环境和人类健康，实现畜禽生产的经济效益、社会效益和生态效益最大化，必须应用生态营养学理论，配制生态营养饲料，实行生态养殖，切实降低畜牧业环境污染和产品残留，促进畜禽养殖业的可持续发展。     

双歧杆菌的代谢及开发前景

双歧杆菌(Bifidobacterium)是典型的益生菌,与机体的许多生理、病理现象关系密切,引起生物学、医学、免疫学、营养学、遗传学、食品学等领域的专家学者的广泛关注.综述了双歧杆菌的生物学特性、厌氧机理、有关酶系合成、分泌到菌体外的物质、质粒研究及双歧杆菌制品的开发利用.     

Large-scale survey of porcine endogenous retrovirus in Chinese miniature pigs

We conducted a large-scale survey on the existence and expression status of porcine endogenous retrovirus (PERV) in seven breeds of Chinese miniature pigs. Genotyping of PERV was examined by PCR using type-specific primers according to the env genotyping method. The presence and expression status of viral gag, pol and env genes were further analyzed in Wuzhishan pigs (WZSP) and Bama minipigs (BMP). The results showed that PERV existed in all 348 genomic DNA samples. The genotype distribution was subtype A-74.43%, subtype B-95.40% and subtype C-30.46%. No expression of subtype C was found in WZSP and BMP. This research obtained an adequate level of information on the molecular epidemiology of PERV in China. The results indicated that it is possible to monitor pig herds for individuals with the lowest PERV prevalence, especially lacking PERV-C.     

育苗基质种类和穴盘规格对番茄幼苗生长发育的影响

选用"宝大906"番茄作供试品种,采用江苏省生产上常用的3种不同基质和5种不同规格的穴盘组成8个处理,对多个番茄幼苗质量性状进行了研究。研究结果表明,基质种类及穴盘规格对番茄幼苗的生长发育均有影响,其中有机活性基质和32孔穴盘对幼苗的生长发育最为有利。     

快速鉴别奶牛乳腺炎细菌或真菌的双重PCR方法

综合多种细菌、真菌DNA模板的提取方法,采用β-巯基乙醇裂解细胞壁,利用蜗牛酶和溶菌酶消化细胞壁,再利用石英砂机械破壁,能彻底破坏细菌、真菌细胞壁,提取高质量的DNA,摸索出一套从奶样中同时提取细菌、真菌核酸的新方法。建立双重PCR方法,同时完成对细菌16SrRNA保守区特异性基因片段和真菌18SrRNA保守区特异性基因片段的扩增,快速诊断奶牛乳房炎是细菌感染还是真菌感染或是混合感染。对采自临床型乳腺炎和隐性乳腺炎病例的共计84个乳样分别用传统细菌学培养法和双重PCR方法对比鉴定。结果表明,双重PCR检测乳样细菌的最小浓度为10^2CFU／mL,检测乳样真菌的最小浓度为10^3CFU／mL。双重PCR方法对细菌的检测与平板培养检测方法比较差异不显著（P〉0．05）,对真菌的检测与平板培养检测方法比较具有更高的检出率（P〈0．01）。     

番茄侧枝营养液扦插苗的栽培效果

以番茄营养液扦插苗为试材,以穴盘苗、基质扦插苗为对照,研究了番茄营养液扦插苗移栽后的生长情况、开花结果情况和果实品质,以检验番茄营养液扦插苗的栽培效果。结果表明:采用番茄侧枝营养液扦插育苗再生调控技术培育的幼苗在株高、叶色指数、着花数等植株生长、开花结果指标上显著优于穴盘苗和基质扦插苗,果实品质与穴盘苗和基质扦插苗无显著性差异。说明番茄营养液扦插苗生长势强,栽培效果好,品质和产量符合设施栽培要求,适合于进行生产应用。     

Effect of replacing alfalfa hay with a mixture of cassava foliage silage and sweet potato vine silage on ruminal and intestinal digestion in sheep

This study aimed to investigate the effects of replacing alfalfa hay (AH) with a mixture of cassava foliage silage and sweet potato vine silage (CSP) (1:1 on a dry matter (DM) basis) on ruminal and intestinal nutrient digestion in sheep. Four wethers were fed a control diet containing 35% of AH and two treatment diets containing 15% and 30% of the CSP as substitute for AH at 1.5 times the metabolizable energy required for maintenance. Replacing AH with the CSP silage did not affect DM intake, whereas it linearly increased (P < 0.05) the intake of ether extract and acid detergent insoluble nitrogen (ADIN). Increasing the CSP substitution linearly decreased (P < 0.05) ruminal DM and neutral detergent fiber (aNDFom) digestibility; however, it did not affect total tract aNDFom digestibility. The CSP substitution did not affect nitrogen (N) intake and duodenal total N flow, whereas it linearly increased duodenal ADIN flow (P < 0.01) and decreased ruminal ammonia‐N concentration (P < 0.01), and intestinal (P = 0.08) and total N digestibility (P < 0.01). These results indicate that replacing AH with the CSP reduced the ruminal N degradation as well as the digestion of ruminal aNDFom and intestinal N.