大花君子兰叶绿体基因组及其特征   总被引：3，自引：0，他引：3  

郑祎  张卉  王钦美  高悦  张志宏  孙玉新 《园艺学报》2020,47(12):2439-2450

采用Illumina MiSeq测序平台对大花君子兰（Clivia miniata）叶片总DNA进行测序，通过组装获得了其叶绿体基因组（cpDNA）全长序列（158 114 bp）。对其cpDNA注释得到135个基因，包含87个蛋白编码基因、40个tRNA基因和8个rRNA基因。采用生物信息学方法对获得的cpDNA进行简单序列重复（SSR）分析和密码子偏好性分析。结果显示：①大花君子兰cpDNA中共有61个SSR位点，其中单核苷酸、二核苷酸、三核苷酸、四核苷酸、五核苷酸和六核苷酸重复数分别为38、9、2、8、3和1个，多数SSR分布在基因间隔区；②大花君子兰cpDNA密码子偏爱以A或U（T）结尾，亮氨酸使用频率最高，半胱氨酸使用频率最低。基于24种植物的cpDNA全长和23种植物的叶绿体ycf2基因序列进行系统发育分析，结果显示大花君子兰与石蒜科植物在同一分支，显示最近的亲缘关系，支持大花君子兰属于石蒜科。基于叶绿体ycf2的系统发育分析结果与基于cpDNA全长的系统发育分析研究结果大部分相同，支持ycf2基因可以代替cpDNA全长用于植物系统发育分析。  相似文献   

论电子阅览室的知识导航与信息服务   总被引：3，自引：0，他引：3  

尤如春 《农业图书情报学刊》2004,16(11):83-85

本文立足于知识导航与信息服务，对网络环境下电子阅览室的服务内容、服务保障、目前面临的现状进行了论述，并提出了服务对策。  相似文献   

云南西双版纳勐腊并殖吸虫成虫扫描电镜观察     

陈韶红  常正山  沈炳贵  陈名刚  张永年  冯正 《中国兽医寄生虫病》2003,11(3):1-2,F002,F003

目的 是通过扫描电镜(SEM)观察勐腊并殖吸虫成虫体棘、口、腹吸盘．为鉴别其虫种提供资料。方法为直接从人工感染的猫体内解剖取出勐腊并殖吸虫成虫，用2．5％戊二醛和1％锇酸固定后，乙醇脱水，离子溅射仪镀金，JSM-820扫描电镜观察。结果表明云南西双版纳瑶瓦区阿括拿青(阿括拿青)虫体的体棘均为丛生型皮棘。新回宽寨老熊青(老熊青)虫体体棘在腹吸盘上方以单棘为主，偶见双棘。腹吸盘下方，为单双棘混合存在。结论认为从SEM形态观察发现勐腊两个不同点采集的勐腊并殖吸虫形态上不完全相同，存在一定的差异。  相似文献   

薄层扫描法测定人工诱生牛黄中主要成分的含量     

王芳生  赵英举  李竟成  白燕  徐礼燊  刘爱茹  张秀琴 《中国兽医学报》1989,(4)

应用岛津CS-910型薄层扫描仪测定了5份人工诱生牛黄和3份天然牛黄中胆酸(CA)、去氧胆酸(DCA)和胆红素(BR)的含量。CA和DCA用荧光扫描,λ_(ex)470nm和λ_(em)550nm;BR用可见光扫描,λ_S402nm和λ_R650nm。测定结果表明,前者中CA和DCA的含量高于后者;BR的含量则前者低于后者。  相似文献   

Influence of death struggle on the structural changes in chub mackerel muscle during chilled storage     

Masashi Ando  Masao Joka  Satoshi Mochizuki  Koh-Ichi Satoh  Yasuyuki Tsukamasa  Yasuo Makinodan 《Fisheries Science》2001,67(4):744-751

ABSTRACT: Chub mackerel (34–35 cm, approximately 500 g), which were caught by fishing with a rod and line at the Bungo Channel, Oita prefecture, were rested overnight in a fish preserve and either killed by decapitation (control group) or allowed to struggle in air for 30 min (struggled group). Muscle samples were excised every 4 h, and measurements on breaking strength and histological observations were done for both groups. The breaking strength of muscle in the control group was significantly higher than that in the struggled group, whereby a decrease in breaking strength was delayed for 12 h compared to the struggled group. Light microscopy showed space extension among muscle cells in association with a decrease in breaking strength. Especially in the struggled group, the extended area was larger and the difference in area was significant at the time when breaking strength showed a significant difference. Using electron microscopy, the extended area showed cut and/or disappeared collagen fibrils. From these results, it was demonstrated that struggling to death promoted the degradation of collagen fibrils and the weakening of connective tissue and, resultantly, led to the faster softening of muscle of chub mackerel.  相似文献   

黄艾美球虫侵犯宿主组织的超微研究     

王维林昆华  殷佩云 《中国兽医寄生虫病》1993,1(4):15-19

利用透射电镜和扫描电镜相结合的技术对黄艾美球虫（E.flavescens）人工感染后的子孢子移动过程及被虫体寄生的宿主细胞形态学变化和粘膜形态学变化进行了观察。子孢子在进入小肠腺上皮过程中需白细胞介导，在白细胞内可发育成球形的滋养体，观察到有两个子孢子侵入同一白细胞的现象，但分别存在于各自的带虫空泡中，黄艾美球虫引起的肠粘膜损伤主要发生于感染177小时之后，其损伤主要表现在绒毛大片脱落，结缔组织裸露，表面可见到大量破损的孔洞及大量肠杆菌，被虫体寄生的腺上皮细胞基部膨胀，微绒毛脱落，细胞核膨大并部分包被虫体，有些细胞核裂解为二。  相似文献   

高校图书馆电子阅览室管理和服务   总被引：5，自引：1，他引：4  

王新敏 《农业图书情报学刊》2004,16(12):81-83

本文介绍湖南科技大学图书馆电子阅览室管理现状与管理系统,探讨高校图书馆电子阅览室的软、硬件的管理维护,推行读者柔性管理和开展电子阅览室特色服务的途径。  相似文献   

扫描及负染电镜在兔脑炎原虫病诊断中的应用     

张柳平  段艳  潘耀谦  夏志平  邹啸环 《动物医学进展》2003,24(6):96-97

12只临床表现头颈歪斜、昏睡、震颤、局部或全身轻瘫的可疑为兔脑炎原虫病的獭兔 ,对其肾脏皮髓交界和尿沉渣分别进行了扫描电镜和负染电镜观察 ,看到了大小为 1～ 1 .5× 1 .4～ 2 .5μm,形态呈卵圆形和杆状的兔脑炎原虫。阳性检出率为 1 0 0 %。说明扫描及负染电镜术是诊断兔脑炎原虫病的一种较为可靠的技术。  相似文献   

Infection process of Rhizoctonia solani on Solanum tuberosum and effects of granular nematicides     

T. W. Hofman  P. H. J. Jongebloed 《European journal of plant pathology / European Foundation for Plant Pathology》1988,94(5):243-252

The infection process ofRhizoctonia solani AG-3 was studied on potato sprouts, cv. Bintje, in growth chamber trials at 15 °C. Initially hyphae ofR. solani grew predominantly in the longitudinal direction of the sprouts (runner hyphae). They tended to follow the junctions between epidermis cells as was observed by SEM. The hyphae formed side-branches mainly half-way of the subterranean parts of the sprouts. They branched several times with short swollen cells to form infection cushions. Lesions developed only underneath the infection cushions and were first observed five days after inoculation. The necrotic area was proportional to the area covered with infection cushions on the sprouts. Depth of the lesions could extend up to the vascular bundle. Sprouts were colonized only in healthy tissue in the epidermal layer underneath the infection cushion and in necrotic tissue. A few days after appearance of the lesions,R. solani formed brown, uninfective mycelium on and in the circumference of these lesions.Aldicarb did not influence any part of the infection process. Ethoprophos delayed the emergence of sprouts, but increased the number of sprouts per tuber. As soon as sprouts had emerged, growth was considerably promoted by ethoprophos. Ethoprophos delayed the appearance of lesions and reduced their size. Oxamyl showed the same effects to a smaller extent.As the size of lesions appears to be proportional to the size of the infection cushions, any agents that change the size of the infection cushions, such as pesticides or antagonists, may alter the severity of the disease.Samenvatting Het infectieproces vanRhizoctonia solani AG-3 werd bestudeerd op aardappelspruiten, cv. Bintje, in een klimaatcel bij 15C. Aanvankelijk groeide de schimmel met runnerhyfen voornamelijk in de lengterichting van de spruit. Via SEM kon waargenomen worden, dat de hyfen hierbij vooral over de begrenzingen van de epidermiscellen groeiden. Het mycelium vormde veel zijvertakkingen, bestaande uit iets gezwollen korte cellen, welke voornamelijk halverwege op het ondergrondse deel van de spruit gevormd werden. Een dichte massa van deze cellen vormde een infectiekussentje. Lesies, welke vanaf vijf dagen na inoculatie werden waargenomen, bevonden zich slechts onder spruitoppervlak bezet met infectiekussentjes. De lesiegrootte was recht evenredig met het spruitoppervlak dat bezet was met infectiekussentjes. De diepte van de lesies reikte tot aan de vaatbundels. De spruit werd alleen door de schimmel gekoloniseerd in gezond epidermisweefsel onder het infectiekussentje en in necrotisch weefsel. Enkele dagen na verschijning van lesies vormde R.solani bruin, niet infectieus, mycelium op en rondom de lesies.Aldicarb had geen effect op het infectieproces. Ethoprophos vertraagde de opkomst en verhoogde het aantal tot ontwikkeling gekomen spruiten per knol in gestoomd zand. Direct na opkomst had ethoprophos echter een sterk groeistimulerend effect. Ethoprophos vertraagde de lesievorming en reduceerde de lesiegrootte, vergeleken met onbehandelde planten. Oxamyl vertoonde deze effecten in geringere mate.Daar de lesiegrootte direct gecorreleerd blijkt met de grootte van het infectiekussentje, mag verwacht worden dat elke beïnvloeding van de ontwikkeling van het mycelium van R.solani, bijvoorbeeld door pesticiden of antagonisten, een verandering van de lesiegrootte ten gevolge heeft.  相似文献   

壳寡糖与草莓细胞结合过程的研究   总被引：6，自引：0，他引：6  

赵小明  于炜婷  白雪芳  李伟  杜昱光  梁鑫淼 《园艺学报》2005,32(1):20-24

 壳寡糖是一类能有效的诱导植物抗病性的重要激发子。本研究用2 - 氨基吖啶酮(22AMAC)标记壳寡糖, 应用激光共聚焦显微成像技术, 研究了壳寡糖与草莓细胞结合过程。结果表明壳寡糖能通过草莓细胞壁与细胞膜结合, 在细胞壁和细胞膜上有其结合位点, 与壳寡糖的结合具有专一性。  相似文献