不同啃食强度对沙拐枣影响的初步研究   总被引：2，自引：2，他引：0  

周志宇  付华  陈善科  苏振军  王长命  塔拉腾  青松 《草业科学》2000,17(3):39-41

在飞播区根据牧畜对沙拐枣啃食程度的不同，采用人工模拟放牧方法对牲畜啃食的绿色部分设置了10％、30％、50％、70％、90％、对照6种不同啃食强度处理，以探讨啃食强度对沙拐枣生长的影响。试验结果表明，30％啃食强度的生物量化90％的高121．37％，比对照高34．85％。沙拐枣的啃食强度在30％－50％时生物量最高，完全不利用或过度利用都会影响其正常生长。  相似文献   

甘蔗黑穗病拮抗细菌的促生长特性及其防治效果研究          下载免费PDF全文

谢光杰  段振峰  王震  余卓新  邢永秀  李杨瑞 《南方农业学报》2021,52(11):3013-3021

【目的】筛选具有拮抗甘蔗黑穗病菌（Sporisorium scitamineum）及促进植物生长特性的细菌，为甘蔗黑穗病的生物防治提供菌株资源和参考依据。【方法】采集出现黑穗病甘蔗株的根际土壤，采用平板对峙培养法分离纯化获得拮抗菌株，通过16S rRNA序列分析明确拮抗菌株的分类地位并分析其促生长特性；采用桶栽试验，研究筛选获得的优良拮抗菌株对甘蔗黑穗病的防治效果。【结果】分离纯化获得68株细菌菌株，其中7株（G1、G10、G12、G14、G20、G21和G23）对甘蔗黑穗病菌具有抑制效果。7株菌株具有产纤维素酶、产几丁质酶、分泌吲哚乙酸（IAA）、产1-氨基环丙烷-1-羧酸脱氨酶（ACC脱氨酶）、嗜铁能力、溶解有机磷、产蛋白酶及产氢氰酸（HCN）等不同程度的促进植物生长特性，特别是3株伯克霍尔德氏菌属（Burkholderia）菌株G1、G10和G23的综合效果更好。用拮抗能力较强的菌株G1、G10、G12和G23防治甘蔗黑穗病的桶栽试验结果表明，4株拮抗菌株处理均可有效抑制黑穗病的发生，提高甘蔗的出苗率和生物量，其中以菌株G23处理的综合效果最好。【结论】分离获得7株对甘蔗黑穗病菌拮抗效果较好的菌株，均具有不同程度的促进植物生长特性，其中以菌株G23的综合效果最好，具有良好的应用前景。  相似文献   

甘蓝型油菜种质资源农艺性状的鉴定与评价   总被引：2，自引：1，他引：1  

关周博  王学芳  赵小光  塔娜  田建华  韦世豪  董育红  张耀文  李殿荣 《江西农业学报》2015,(7)

为了解不同地区种质资源在农艺性状上的遗传多样性,对来自国内318份油菜种质资源品种(系)的9个农艺性状指标进行了鉴定和评价。结果表明:9个农艺性状具有较大的遗传变异潜力,变异系数最大的是有效分枝高度,为0.555296;其次是一次有效分枝数,为0.450183;变异系数最小的是千粒重,为0.157786。在不同省份所提供的种质资源中,各性状平均值差异显著,而且不同省份的品种同一性状的变幅也不同;主花絮有效长度较长和有效角果数较多的品种主要出现在株高为160~179 cm的品种中;探索了初花期与千粒重和单株产量的关系,并评价推荐了部分优良种质资源供育种应用。  相似文献   

Biomechanical evaluation of double Krackow sutures versus the three‐loop pulley suture in a canine gastrocnemius tendon avulsion model     

L Wilson  TA Banks  P Luckman  B Smith 《Australian veterinary journal》2014,92(11):427-432

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沙地柏人工林和天然林风沙土特性研究   总被引：1，自引：0，他引：1  

拓飞  董治宝  南维鸽  杨树俊  武玉叶  李强 《水土保持研究》2021,(2):80-87

为了深入了解固沙植被恢复对土壤理化性质的影响,以毛乌素沙地东南缘沙地柏人工林和天然林为研究对象,通过收集灌丛下5个土层(0-100 cm)的土壤样品,分析其土壤颗粒组成及8个理化指标,探讨了沙地柏生长对风沙土特性的影响。结果表明:研究区土壤粒度组成以砂粒(体积分数97.09%)为主,其次是粉粒和黏粒,并形成以中砂(50.26%)为主的单峰,土壤弱碱性,其养分含量整体水平低,且具有明显表层聚集现象。土壤养分含量与土壤粒度之间存在良好的相关性,表现为土壤有机质、速效钾和盐分含量与细沙物质(粒径<100μm)含量呈线性正相关,与粗砂物质(100~500μm)呈线性负相关。沙地柏生长对风沙土改良效果呈现出人工林16 a树龄优于7 a树龄,天然林地迎风坡优于背风坡。整体上,造林时间增加土壤颗粒的粗细分配趋于良好态势发展,土壤结构优化,土地荒漠化进程减缓。因此,沙地柏可作为毛乌素沙地生态恢复工程的优良灌木。  相似文献   

绵羊放牧方式及强度对围封恢复草场牧草细胞壁成分及营养价值的影响     

塔娜  德庆哈拉  那日苏 《家畜生态》2013,(7):58-63

选取内蒙古自治区典型草原区封育恢复中天然放牧草场,进行毛肉兼用细毛羊的暖季放牧试验.采用2×5完全随机试验设计,设定不同放牧方式（不放牧,连续放牧,四区、五区、六区轮牧）及2种放牧强度（1.0,1.4 hm2/un.sh）,运用酶分析方法分析比较了围封过程中放牧绵羊对封育草场牧草细胞壁成分月动态变化及营养价值的影响.结果表明,整个暖季放牧期内,不同放牧区牧草营养物质含量主要受到放牧方式的显著影响（P＜0.05）.具体表现为,不放牧处理牧草细胞壁有机物（OCW）含量始终显著低于各放牧处理,不同放牧处理间没有明显差异;划区轮牧处理牧草始终保持着较高的消化性部分且显著高于连续放牧处理;不放牧处理牧草始终保持着较高的Oa和较低的Ob,而连续放牧处理与其相反,各轮牧处理间没有显著差异;轮牧处理总可消化养分（TDN）和代谢能（ME）含量较高,尤其在牧草生长旺盛期（八月份）,六区轮牧放牧场牧草可利用营养物质含量最高,营养价值最高.  相似文献   

三维模式下培养时间对奶牛乳腺上皮细胞酪蛋白基因表达的影响     

王秀美  侯先志  敖长金  高民  考桂兰  高爱武  兰儒冰  塔娜 《动物营养学报》2013,25(7):1526-1533

本试验旨在研究三维模式下培养时间对奶牛乳腺上皮细胞(BMECs)酪蛋白基因表达的影响。采用3头健康的3～5岁泌乳黑白花奶牛的乳腺组织,将BMECs经1代纯化后进行三维培养,在三维模式下分别培养3、5、7、9 d,测定BMECs中αs1-酪蛋白、β-酪蛋白、κ-酪蛋白的基因表达量。结果表明,利用三维模式培养5 d的BMECsαs1-酪蛋白和κ-酪蛋白基因表达量极显著高于培养3、7、9 d(P<0.01);利用三维模式培养5 d的BMECsβ-酪蛋白的基因表达量极显著高于培养3、7 d(P<0.01),高于培养9 d,但差异不显著(P>0.05)。结果显示,三维模式下培养时间影响BMECs中αs1-酪蛋白、β-酪蛋白、κ-酪蛋白的基因表达量,本试验条件下最佳培养时间为5 d。  相似文献   

A simple and sensitive assay for distinguishing the expression of ricin and Ricinus communis agglutinin genes in developing castor seed (R. communis L.)     

Chen GQ  He X  McKeon TA 《Journal of agricultural and food chemistry》2005,53(6):2358-2361

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The effect of ivermectin treatment of late pregnant dairy cows in south-west Victoria on subsequent milk production and reproductive performance   总被引：1，自引：0，他引：1  

TA WALSH  PJ YOUNIS  JM MORTON† 《Australian veterinary journal》1995,72(6):201-207

SUMMARY A total of 498 dairy cows in 5 predominantly pasture-fed herds were allocated to pairs. One cow in each pair was treated with a single dose of ivermectin during the dry period. Treated and untreated cows were managed as a single group throughout the trial. Most cows calved between 45 and 115 days after treatment. When data from all herds were pooled, treated cows produced an extra 74 L of milk over the first 100 days of the subsequent lactation (95% confidence interval 20 to 128). Means were greater among treated groups relative to untreated groups in all 5 herds. However, when analysed individually, differences were statistically significant (P < 0.05) in 1 herd only. Over the complete lactation, mean milk volume for treated cows was 86 L greater than for untreated cows (95% confidence interval of difference -57 to 229; P = 0.24). Untreated cows produced 2473 L and 5883 L for the first 100 days of lactation and for the complete lactation, respectively. Milk production responses to treatment did not vary significantly with parity, body condition score, previous production index, calving date category or with plasma pepsinogen concentration or faecal egg count at the time of treatment. Faecal egg counts and plasma pepsinogen concentrations were low at the start of the study. The interval from calving to conception was 4.8 days less in treated cows (95% confidence interval 1.2 to 8.2) relative to untreated cows when data from all 5 herds were pooled. Differences within individual herds were not statistically significant.  相似文献   

Herd and within-herd BoHV-1 prevalence among Irish beef herds submitting bulls for entry to a performance testing station     

O'Grady L  O'Neill R  Collins D  Clegg T  More S 《Irish veterinary journal》2008,61(12):809-815

Infectious bovine rhinotracheitis (IBR), caused by bovine herpes virus 1 (BoHV-1), may result in various clinical consequences, including severe respiratory disease and conjunctivitis, venereal disease and reduced reproductive performance and abortion. This paper presents the serosurveillance findings from an intake of bulls into a performance testing station in Ireland during November 2007. The herd and within-herd BoHV-1 prevalence in 53 Irish beef herds and the risk factors for infection in these herds were determined, among bulls entering a beef performance testing station in Ireland. BoHV-1 status was determined for 41 herds, of which 30 (73.2%) herds were infected and the mean within-herd BoHV-1 prevalence was 28 (± 20)%. Multivariate exact logistic modelling revealed increasing numbers of contiguous herds and decreasing percentage of males within the herd as significant risk factors associated with infected herds. These findings highlight the high prevalence of BoHV-1 infection in those Irish beef herds that submitted bulls to this performance testing station, and raise concerns regarding IBR control nationally.  相似文献