鸡细菌性腹泻防治

我国从古至今都是农业大国,在经济体制改革的推动下,我国工业发展迅猛的情况下,农业依旧是我国的产业支柱,对促进我国经济发展有极大帮助。养殖业是农业的重要部分,而养殖业中,鸡养殖有占据极大比例,且其规模也在不断扩大。近年,鸡的一些疾病发病率逐渐增加,其中细菌性腹泻是常见的1种,会影响鸡群身体健康与生长发育,甚至会导致其死亡,危害极大,给养殖户乃至养殖产业造成极大的经济损失,做好鸡细菌性腹泻预防与治疗工作尤为重要。该文对鸡细菌性腹泻的特点进行探讨,并提出一些防治措施。     

马尾松叶表微生物多样性

为发掘对林木生长发育有利的优良微生物资源,并筛选适合叶表微生物的收集方法,以马尾松针叶为试验材料,分别用悬摇法和超声波法收集马尾松叶表微生物,用扩增子高通量测序技术、MUSCLE和Qiime软件研究马尾松叶表微生物的多样性。结果表明:扫描电镜观测结果显示,马尾松针叶表面定殖有大量微生物,包括真菌(菌丝及孢子)和细菌。扩增子高通量测序结果表明,马尾松叶表微生物物种丰富,包含细菌运算分类单位(OTUs)490个,真菌OTUs 1273个。马尾松叶表细菌以未分类的蓝细菌属(unidentified_Cyanobacteria)(36.53%)、未分类的拜叶林克氏菌属(unidentified_Beijerinckia)(28.60%)、鞘氨醇单胞菌属(Sphingomonas)(2.35%)为优势属;叶表真菌以枝孢属(Cladosporium)(2.45%)、拟盘多毛孢属(Pestalotiopsis)(0.92%)、无头孢菌属(Capnobotryella)(0.91%)为优势属。针对叶表细菌多样性的研究表明,悬摇法和超声波法均有较高的物种检出度;在叶表真菌多样性的研究中超声波法优于悬摇法,但超声波法样品间数据变异性较大,测定结果不稳定。     

影响番茄离体培养再生的主要因素探讨

以5个番茄品种的子叶和下胚轴为外植体,对无菌苗的生理状态、激素组合、激素浓度和基因型等影响组培效果的主要因素进行探讨,建立了番茄的高效离体培养再生体系。结果表明,下胚轴和子叶均得到了高达100%的出愈率和95%以上的分化率;最佳的品种是T431;最佳激素组合为ZT1.0mg·L-1和IAA1.0mg·L-1。     

糖槭叶枯病发病规律及防治

糖槭叶枯病 Phyllosticta negundinis病菌孢子放散开始期和高峰期与每年的温、湿度变化有关。病害发生严重程度与降雨量关系密切 ,降雨早且量大时病害严重。病菌以分生孢子器和分生孢子在病叶上越冬 ,通过气流传播成为翌年初侵染源。喷洒 70 %甲基托布津可湿性粉剂 10 0 0倍液和 75%百菌清可湿性粉剂 80 0倍液均能收到较好的效果     

感染反刍动物的几种常见梭状芽孢杆菌

梭状芽孢杆菌属的成员在自然界中是一种非常独特的种类，当其进入到反刍动物体内时，常会引起肌肉和软组织感染、肠道疾病和神经中毒性疾病。梭状芽孢杆菌引起反刍动物发病的机理通常是间接地通过其产生的一种或多种毒素(毒蛋白质)来致病。本文从肌肉和软组织感染、肠道疾病以及神经中毒性感染三个方面探讨了引起感染的梭状芽孢杆菌。     

浊度法测定维生素C注射液细菌内毒素含量

应用BET-32型细菌内毒素测定仪定量测定维生素C注射液的细菌内毒素含量，干扰试验表明，维生素C注射液在400倍稀释时，测定内毒素的干扰最小。7个不同批号的维生素C注射液测定结果显示，7批的回收率均符合测定要求，其中4个批号的人用维生素C注射液内毒素含量符合药典标准，兽用3个批号产品的内毒素含量偏高。     

罐藏番茄新品种红杂18的选育

红杂１８是以红２１３为母本，黄苗试材９３７５为父本，配制成适宜罐藏加工和长途运销的番茄一代杂种。具有高抗ＴＭＶ、中抗ＣＭＶ、果实硬度高、抗裂、耐压、耐贮运、果实加工性状优良等特点。已在新疆、甘肃、宁夏、广西、云南等省区的加工番茄生产基地和远运外销生产基地推广６４９．８ｈｍ２。     

一次防治大豆灰斑病籽粒灰斑

通过室内及田间大豆不同生育期接种试验证明，籽粒感染灰斑病的关键时期是Ｒ３－Ｒ５期．Ｒ２期以前侵染不造成籽粒斑驳，据此提出一次防治大豆籽粒灰斑病的关键时期为Ｒ２－Ｒ４期．     

Morphological characterization of the interaction between Diplocarpon rosae and various rose species

Blackspot, caused by Diplocarpon rosae , is the most severe and ubiquitous disease of garden roses, but information is lacking about genotype-specific forms of resistance and susceptibility of the host. Macro- and microscopic analyses of 34 rose genotypes with a defined monoconidial culture black spot inoculum identified susceptible and resistant rose genotypes and further genotype-specific subdivisions, indicating the presence of partial forms of resistance and different resistance mechanisms. In total, eight interaction types were characterized, five representing compatible (types 1–5) and three representing incompatible interactions (types 6–8). The incompatible interactions were characterized by the lack of any visible fungal structures beneath the cuticle (type 8), single-cell necroses (type 7) or necroses of larger cell clusters (type 6), the latter two types with penetration hyphae and haustoria in epidermal cells.     

Notes on the role of water potential in the pathogenesis of fire blight,caused by Erwinia amylovora

The rate of multiplication of fire blight causing bacteriumErwinia amylovora (Burrill) Winslow et al. depends on the availability of water. Water availability can be quantified by means of the parameter water potential. The relationship between water potential and relative multiplication rate ofE. amylovora was derived from experiments of L. Shaw (1935). This relationship appears to be applicable toE. amylovora in plant tissues and in nectar of flowers.Multiplication and expansion ofE. amylovora in a restricted space, e.g. an intercellular hole, creates a pressure, which may cause schizogenic cavities in soft tissue. Strong tissue, however, may be able to resist this multiplication pressure of the bacteria, so that symptom progression can be prevented. A hypothesis is formulated on how the multiplication pressure may be quantified by means of the parameter water potential. Expansion of bacterial ooze may alo be due to absorbtion of water without increase of dry weight (e.g. a daily cycle of shrinkage and expansion). This expansion may give rise to a swelling pressure, which again may be quantified by means of the parameter water potential.Samenvatting De vermenigvuldigingssnelheid van de bacterie die bacterievuur veroorzaakt (Erwinia amylovora (Burrill) Winslow et al.,), hangt af van de beschikbaarheid van water. De beschikbaarheid van water kan worden gekwantificeerd met de parameter waterpotentiaal. De relatie tussen waterpotentiaal en relatieve vermenigvuldigingssnelheid vanE. amylovora werd afgeleid uit experimenten van L. Shaw (1935, Cornell University Agricultural Experiment Station, Ithaca. Memoir 181). Deze relatie kan zowel worden toegepast op de pathogenese in planteweefsel als op de epifytische ontwikkeling in nektar.Vermenigvuldiging vanE. amylovora in een beperkte ruimte, bijvoorbeeld in een intercellulaire holte, creëert een druk, die tot scheuren van zacht weefsel kan leiden. Sterk weefsel kan de vermenigvuldigingsdruk van de bacteriën vermoedelijk wel weerstaan, zodat uitbreiding wordt verhinderd. In een hypothese wordt beschreven hoe de vermenigvuldigingsdruk zou kunnen worden gekwantificeerd met behulp van de parameter waterpotentiaal. Wateropname door bacterieslijm zonder toename van het drooggewicht (bijvoorbeeld een dagelijkse gang van krimpen en zwellen) kan ook leiden tot een druk. Deze druk kan eveneens worden berekend met de parameter waterpotentiaal.