甜樱桃果实LOX、PPO和POD活性变化特性及采后处理效应

以红灯和萨米托果实为试材,研究了冷藏条件下2种甜樱桃果实的LOX、PPO和POD活性变化特性,以及气调、1-MCP和自发气调处理对这3种酶活性变化的影响效应。结果表明:不同品种间的甜樱桃果实LOX、PPO和POD活性变化存在显著差异,3种酶在萨米托果实中的活性均显著高于红灯,但活性增加速率和变化趋势有所不同,即红灯果实的LOX活性在贮藏初期增加幅度高于萨米托,两品种的PPO活性变化趋势一致,而POD活性的差异主要表现在贮藏前期,说明LOX、PPO和POD的活性变化与品种特性及果实衰老存在密切关系。采后气调、1-MCP和自发气调处理的影响效果因品种不同而异,进一步表明这3种酶在甜樱桃果实采后衰老过程中起着重要作用,但确切机理尚需进一步探讨。     

禽波氏杆菌病原性研究及防治初探

本文介绍了禽波氏杆菌的培养特性、药物敏感性及生化特性，重点进行了禽波氏杆菌对雏鸡的致病性研究，结果证明本菌主要引起雏鸡的急性死亡，主要病变为肺脏出血，肝脏出血、边缘坏死，肾脏出血，腺胃、肌胃浆膜出血，肠道出血。不同日龄的雏鸡对禽波氏杆菌的抵抗力不同，与日龄成正相关。同时还用不同来源的8株禽波氏杆菌制成蜂胶灭活苗，并分别免疫1日龄和11日龄雏鸡，结果发现本疫苗对雏鸡的保护率低。     

Further analysis of VNTR and MIRU in the genome of Mycobacterium avium complex, and application to molecular epidemiology of isolates from South America

All members of Mycobacterium avium complex are serious pathogens for humans and animals. The aim of this study was to look for and analyze VNTR-MIRU loci in the genome of M. avium complex and their preliminary application to test these isolates. In the present study, we identified 22 novel VNTR-MIRU by using Tandem Repeat software: five with a structure similar to MIRU and 17 without MIRU structure; these latter were designated as VNTR. Most VNTR were located within predicted coding regions. Most MIRU were intercistronic with their extremities overlapping the termination and initiation codons of their flanking genes. Some of these VNTR-MIRU exhibited polymorphism among M. avium complex isolates due to insertion or deletion of whole repeats and/or of nucleotide sequence degeneration. We determined the variability of six VNTR-MIRU loci in 21 M. avium subsp. hominissuis and 26 M. avium subsp. paratuberculosis. The analysis identified 15 different alleles with the combination of six VNTR-MIRU in the 21 M. avium subsp. hominissuis with 16 different IS1245 RFLP and four different profiles with PCR-restriction analysis of hsp65 (PRA). However, neither the six VNTR-MIRU loci nor the PRA were able to distinguish M. avium subsp. paratuberculosis isolates with five different IS900 RFLP profiles. In conclusion, some of the VNTR-MIRU loci identified were useful to differentiate M. avium subsp. hominissuis but not M. avium subsp. paratuberculosis isolates here included. However, we observed polymorphism in VNTR-MIRU loci between M. avium subsp. hominissuis and M. avium subsp. paratuberculosis genomes, which could be important in the understanding of the obvious differences in the pathogenic effects of these mycobacteria.     

An Enzyme-linked Immunosorbent Assay using Immonoaffinity-purified Antigen in the Diagnosis of Caprine Paratuberculosis and Its Comparison with Conventional ELISAs

An enzyme-linked immunosorbent assay (APA-ELISA) using an immunoaffinity-purified antigen was developed and compared with the unabsorbed and absorbed ELISA procedures, using a crude antigenic preparation, for its efficacy in detecting antibodies in goat sera against Mycobacterium avium paratuberculosis. Serum samples from 89 goats belonging to three different flocks, two with a history and evidence of paratuberculosis and one without it, were subjected to each ELISA, which had been standardized on known positive sera from goats experimentally infected with paratuberculosis. Faecal culture, faecal examination and histopathology were used as indicators of infection. The diagnostic sensitivities of the unabsorbed, absorbed and APA-ELISA were 81.8%, 77.3% and 77.3% and the specificities were 90.6%, 93.7% and 96.8%, respectively. The positive predictive values of APA-ELISA (94.4%) was the highest, followed by absorbed ELISA (80.9%) and unabsorbed ELISA (72.0%). The negative predictive values for APA-ELISA, absorbed ELISA and unabsorbed ELISA were 93.0%, 92.7% and 93.8%, respectively. The results indicated the value of APA-ELISA in avoiding the need to absorb individual test sera with Mycobacterium phlei and giving more consistent results than the absorbed ELISA. The APA-ELISA was also better than the other two procedures in terms of specificity and positive predictive values.     

B亚型禽白血病病毒所致免疫抑制条件下共感染禽波氏杆菌对雏鸡的影响

选择B亚型禽白血病病毒（ALV-B）感染雏鸡造成免疫机能低下,建立免疫抑制模型,以探索免疫抑制条件下共感染禽波氏杆菌后对雏鸡致病性的影响。设计了ALV-B单独感染组,B.avium单独感染组,ALV-B和B.avium共感染组,空白对照组,并且比较相互之间的差异。通过对雏鸡免疫学指标、生长性能及病毒血症和排毒状况的检测,对二者混合感染雏鸡的影响进行了研究。结果显示,ALV-B和B.avium共感染能引起雏鸡的免疫力低下,表现为免疫器官的发育、抗体的产生、淋巴细胞的转化、IL-2和IFN-γ的合成和分泌等受到明显抑制;混合感染组延长了B.avium的病程,增强其对雏鸡的致病性;同时机体出现明显的生长迟滞现象,尤其是第5周龄,共感染组平均体质量仅相当于对照组的40%。结果表明,ALV-B和B.avium在雏鸡体内的增殖方面起协同作用,从而促进了病原在鸡群间的散播;而B.avium对ALV-B导致的病毒血症有一定的抑制作用。在ALV-B免疫抑制作用下,B.avium对雏鸡的致病性显著增强。     

欧洲大樱桃的组织培养与快速繁殖

以欧洲大樱桃幼嫩茎段为外植体材料,研究了不同浓度6-BA和IAA外源激素配比组合和不同培养温度对樱桃茎段离体培养的影响,结果表明:在附加6-BA 1.5 mg/LI、AA 0.3 mg/L的MS培养基上茎段外植体生长健壮,芽分化数和诱导率较高,为茎段初代培养的最适培养基。温度对茎段组织培养再生不定芽也有一定的影响。在培养温度为先15℃、后25℃的条件下,茎段外植体芽分化数为7.4个,芽诱导率为99%。这表明经低温15℃条件下处理的外植体比其他温度条件更能诱导芽分化。     

甜樱桃组培苗的生根研究

研究了基本培养基(1/2WPM,1/2F14,1/2MS)、培养方式(液体培养、根部黑暗、两步生根法)和生长素浓度对甜樱桃(PrunusaviumL.)品系"6-7"组培苗生根的作用效果。结果表明,1/2F14为最适基本培养基;液体培养对组培苗的生根有很大的促进作用,根部黑暗条件培养次之,两步生根法作用不明显;生长素质量浓度配比以IBA1.0mg/L+NAA1.0mg/L效果最好,生根率可达89.7%。据此认为,要提高组培生根困难的木本植物的有效生根率,以岩棉为支撑物的液体培养是一项有效措施。     

Systemic Mycobacteriosis in an Aborted Thoroughbred Fetus in Japan

A male Thoroughbred fetus was aborted on day 251 of pregnancy. Gross and histological examinations detected systemic granulomatous lesions in many superficial and visceral lymph nodes and organs including the liver, tonsils, lungs, thymus, spleen, right thyroid gland and gastrointestinal tract, and suppurative placentitis, pyogranulomatous amnionitis and intralesional acid-fast bacilli were also detected. An examination of the DNA base sequence of the β subunit of RNA polymerase demonstrated that Mycobacterium avium strain 104 had infected several organs. To the best of our knowledge, this is the first report of equine fetal mycobacterial infection in Japan.     

秋季叶施尿素对甜樱桃产量与品质的影响

以田间7年生‘红灯’甜樱桃/大青叶为试材,研究了叶面喷施尿素对甜樱桃产量与品质的影响。结果表明:叶面施氮有利于甜樱桃花器官发育,提高完全花比例和坐果率,增大果实体积,提高果实单果重,进而提高产量;同时,提高果实糖含量及果实糖酸比;总之,叶面施氮提高了甜樱桃果实的产量和品质。     

基于ITS序列的中国樱桃、欧洲甜樱桃和毛樱桃种内遗传多样性及种间关系分析

对中国樱桃[Cerasus pseudocerasus(Lindl.)G.Don](地方种质35份,野生资源35份),欧洲甜樱桃[C.avium(L.)Moench](18份)和毛樱桃[C.tomentosa(Thunb.)Wall.](7份)共95份材料的核糖体内转录间隔区(ITS,internal transcribed spacer)序列进行了测定和分析,以期从ITS的DNA序列变异角度揭示种内遗传多样性及种间遗传关系。结果表明:(1)96条ITS序列比对后长度为712 bp,G+C含量为58.1%,检测到71个变异位点(9.97%),共定义了37个单倍型;中国樱桃、欧洲甜樱桃和毛樱桃的单倍型多样性和核酸多样性分别为0.840和0.00466、0.928和0.00396、0.905和0.00564,中国樱桃中栽培种质遗传多样性明显低于其野生资源;(2)种间遗传关系显示,中国樱桃与欧洲甜樱桃之间的遗传距离较近(0.019),而与毛樱桃遗传距离较远(0.048);(3)邻接聚类和单倍型网络分析显示3个种分别聚为3个分支,种间具有较大的遗传分化。同时,选择3个种的代表单倍型进行其ITS序列的二级结构预测分析,3个种之间ITS1区、ITS2区的二级结构差异较大,最小自由能差异显著,进一步揭示了3个种间的遗传关系较远。综合分析认为,3个樱桃种内均具有较高的遗传多样性,种间具有较大的遗传分化,遗传关系较远,其中毛樱桃与中国樱桃和欧洲甜樱桃的遗传关系均较远。