沙田柚黄龙病病原体的电镜观察与PCR检测

柑桔黄龙病可以侵染沙田柚而产生典型的‘斑驳’症状。我们通过电镜观察表明,带病沙田柚的病原体在形态,大小和构造上均与柑桔黄龙病病原体（类细菌）相似：PCR扩增也证明其病原体DNA与柑桔黄龙病病原体的PCR产物具有很高的同源性。     

1964例围产期孕妇阴道分泌物常见病原体分析

目的探讨围产期孕妇阴道分泌物常见病原体的感染状况,减少不良妊娠的发生。方法假丝酵母菌(C)、滴虫(T)检测采用涂片法,细菌性阴道炎(BV)检测采用唾液酸酶法,淋球菌(NG)检测采用平板培养法,解脲支原体(UU)检测采用人工培养法,沙眼衣原体(CT)检测采用乳胶免疫层析法。结果 1 964例围产期孕妇中病原体感染者共360例,占总人数的18.33%(C 9.41%、T 0.46%、BV 6.36%、NG 0.00%、UU 4.53%、CT 1.73%)。其中单一病原体感染者为281例,占总人数的14.31%;两种或两种以上病原体感染者为79人,占总人数的4.02%。结论抚顺地区围产期孕妇阴道分泌物病原体构成复杂,病原体主要以假丝酵母菌和细菌性阴道炎为主,其次是解脲支原体,部分孕妇可同时感染多种病原体。     

沙田柚不同外植体离体培养与植株再生的研究

利用组织培养进行柑桔良种的快速繁殖可以克服常规方法费时的缺点 ,为进一步进行无病原体苗木繁育、诱变育种及遗传转化创造有利条件。目前我国开展此项工作较为广泛 ,已先后在红江橙 [1 ]、柠檬 [2 ]、金柑 [3]、甜橙 [4]及蕉柑 [5]等柑桔类中建立了组织培养的再生体系 ,但在柚类中相关的研究较少。笔者以沙田柚为材料 ,在离体培养条件下 ,成功诱导上下胚轴、根段及子叶的不定芽形成和植株再生。1 　材料与方法1 .1 　植物材料沙田柚种子 ( Citrus grandis Osbeck cv.Shatian Yu)经表面消毒后黑暗培养无菌苗 ,当苗长至 2 0 d左右时 ,将上…     

柑桔的原生质体培养和体细胞杂交

本文论述了柑桔原生质体分离、培养及其再生植株的条件和影响因素,并对柑桔体细胞杂交和胞质杂交的研究进展及应用前景进行了概述和讨论。     

甲真菌病多点平皿培养法与常规试管培养法的比较

目的比较甲真菌病病原体检测中多点平皿培养法与常规试管培养法的差异。方法选择2004年10月～12月及2005年10月～12月病甲标本,分别采用多点平皿培养法(试验组)和常规试管培养法(对照组)分离病原体并作菌种鉴定。结果多点平皿培养法和常规试管培养法之间比较,阳性率分别为68.4%和49.3%(P=0.0029),污染率分别为13.2%和4.6%(P=0.0246)。致病菌分离结果:对照组皮肤癣菌75.7%,酵母菌18.9%,非皮肤癣菌霉菌5.4%;试验组则分别为46.2%,34.6%和16.7%。两组分离菌种比较,P值均<0.05。试验组共检出2例混合感染,对照组则无。结论多点平皿培养法阳性率高,可以提高对甲真菌病的病原菌的检出率,尤其是对非皮肤癣菌酵母菌和霉菌的检出率,且有助于发现甲真菌病的混合感染。但多点平皿培养法污染率亦高,应规范无菌操作。     

基于最小矩形法的柑桔横径实时检测方法研究

农产品的大小是农产品分级的重要特征之一．本文以柑桔为研究对象,对利用计算机图像处理技术检测柑桔横径的方法进行了探索．研究了柑桔图像的平滑和边缘提取方法,比较了利用Sobel算子和跟踪虫（tracking bug)法所得到的柑桔边缘,发现跟踪虫法寻找边界的速度比用Sobel算子快,且不需要进行细化处理．为了适应实际生产中柑桔方向的随机性和外形的不规则性的要求,使柑桔尺寸检测的方法有更好的适应性,设计了一种利用柑桔的最小外接矩形（MER）求最大横径的方法,并在柑桔的外形尺寸检测中进行了验证,实际最大横径Dr与预测最大横径的相关性为0．9982,利用此方法估测果径的最大误差在1．30mm以内,最大相对误差为2.64％,平均相对误差为1.35％,GB／T12947-91鲜柑桔分级标准中均以5mm为分等标准差,故MER法的精度能满足实际生产中柑桔分级精度的要求．本研究结果不仅为进一步研究开发基于图像处理技术的柑桔品质检测系统打下了基础,而且可用于对其他农产品进行检测．     

硝酸银对常见呼吸道病原体的抑制作用

目的证实硝酸银对常见呼吸道病原体具有抑制作用。方法采用血凝试验和鸡胚培养法观察硝酸银对副流感病毒的抑制作用;采用细胞培养法观察硝酸银对腺病毒的抑制作用;采用细菌培养法观察硝酸银对肺炎链球菌和乙型溶血型链球菌的抑制作用。结果硝酸银对副流感病毒和腺病毒有明显的抑制作用,对肺炎链球菌和乙型溶血型链球菌有极强的杀菌作用。结论硝酸银对常见呼吸道病原体有明显的抑制作用。     

同工酶分析在柑桔研究中的应用

本文概述了同工酶分析在柑桔分类、亲缘关系鉴定、遗传育种、病理检测和离体培养等研究领域的应用,并对同工酶分析在柑桔上的应用前景提出了一些看法。     

柑桔植物的数值分类学研究

本文用系统聚类法和对应分析法对59份柑桔及其近缘植物枳和金柑三个属的分类群进行了数值 分类学研究。 结果表明,在栽培柑桔中,枸橼Citrus medica、柚Citrus grandis、宽皮柑桔Citrusreticulata是三大基本类型。 本文还对些种类的分类地位作了探讨。     

恒温扩增芯片法在重症监护病房肺部感染患者诊断中的应用

目的评价恒温扩增芯片法在重症监护病房肺部感染患者下呼吸道感染病原体检测中的效果。方法收集合格痰标本146例,通过恒温扩增芯片法和细菌培养法检测病原体,对两种方法检测结果进行分析。结果 146例痰液标本中,恒温扩增芯片法检出阳性标本114例(阳性率为78.1%),其中单一致病菌感染42例,2种及以上致病菌混合感染72例。45例标本检测到mecA基因,其中13例为耐甲氧西林金黄色葡萄球菌。146例痰标本中,有109例痰标本同时进行了痰培养检测,痰培养阳性率为67.9%(74/109),相应的恒温扩增芯片法检测阳性率为82.6%(90/109);痰培养结果阴性共计35例,与之相符合的恒温扩增芯片法检测阴性共计16例(阴性符合率45.7%)。恒温扩增芯片法对肺炎链球菌、肺炎克雷伯菌、铜绿假单胞菌、嗜麦芽窄食单胞菌、流感嗜血杆菌的阳性检出率明显高于痰培养,差异具有统计学意义。恒温扩增芯片法检测到2例结核分枝杆菌复合群、1例军团菌、1例肺炎支原体,痰培养检测到3例奇异变形杆菌。结论本实验室所开展的恒温扩增芯片法在重症监护病房肺部感染者下呼吸道病原体检测方面的优势体现在阳性率高、检测时间短,可为临床肺部感染诊断提供及时准确的参考依据。     

柑橘生物技术研究进展

综述了近年来国内外柑橘生物技术的研究进展,主要涉及到以下4个方面:(1)组织培养(包括胚培养、胚珠培养、胚乳培养、花药培养和营养器官培养)与快繁、脱毒和种质资源保存;(2)原生质体培养、再生和融合及体细胞杂种在柑橘砧木及接穗品种改良中的应用;(3)分子标记技术在柑橘遗传多样性检测、基因定位、亲缘关系分析及体细胞杂种鉴定等方面的应用;(4)转基因技术。目前,现代生物技术是柑橘传统育种的有效补充,已成为柑橘遗传改良、种质资源创新和科学研究的重要技术。     

体细胞胚胎发生在柑桔生物技术中的应用

本文概述体细胞胚胎发生在柑桔原生质体培养、花药培养、苗木脱毒、胚乳培养、快速繁殖、抗盐突变体筛选和基因工程等研究领域的应用,并对胚胎发生在柑桔生物技术上的应用提出一些看法。     

Production of pectin lyase by Penicillium griseoroseum as a function of the inoculum and culture conditions

Optimum activity of an extracellular pectin lyase produced by Penicillium griseoroseum in submerged culture was after 120 h using 0.1% (w/v) citrus pectin as substrate. Sucrose at 0.1% (w/v) stimulated enzyme production and citrus pectin gave the highest activity of enzyme per unit growth.     

Establishment of Asian citrus psyllid (<Emphasis Type="Italic">Diaphorina citri</Emphasis>) primary cultures

The Asian citrus psyllid (AsCP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a highly competent vector of the phloem-inhabiting bacterium Candidatus Liberibacter asiaticus associated with the citrus disease huanglongbing (HLB). Commonly referred to as citrus greening disease in the USA, HLB causes reduced fruit yields, quality, and ultimately tree death and is considered the most serious citrus disease. HLB has become a major limiting factor to the production of citrus worldwide. Studies of HLB have been impeded by the fact that C. Liberibacter has not yet been cultured on artificial nutrient media. After being acquired by a psyllid, C. Liberibacter asiaticus is reported to replicate within the psyllid and is retained by the psyllid throughout its life span. We therefore hypothesized that C. Liberibacter asiaticus could be cultured in vitro using psyllid cell cultures as the medium and investigated the establishment of a pure culture for AsCP cells. Several commercially available insect cell culture media along with some media we developed were screened for viability to culture cells from AsCP embryos. Cells from psyllid tissues adhered to the plate and migration was observed within 24 h. Cells were maintained at 20°C. We successfully established primary psyllid cell cultures, referred to as DcHH-1, for D. citri Hert-Hunter-1, with a new media, Hert-Hunter-70.     

Accumulation of Elsinochrome Phytotoxin does not Correlate with Fungal Virulence among Elsinoë fawcettii Isolates in Florida

Citrus scab caused by Elsinoë fawcettii is cosmopolitan in humid citrus-growing areas. We have previously demonstrated that production of non-host selective elsinochrome phytotoxin is a prerequisite for fungal full virulence and lesion formation. In this study we evaluated 71 field-collected isolates from Florida for pathogenicity and toxin production and found most of the isolates to be pathogenic to rough lemon, grapefruit and sour orange and able to produce elsinochromes in axenic culture. Elsinochromes were recovered, for the first time, from leaf lesions infected by 21 isolates, including four isolates that did not produce any measurable toxin in culture. There was no direct correspondence between the level of elsinochrome production in culture and virulence among the isolates. However, Elsinoë isolates failed to produce elsinochromes in culture and in planta were non-pathogenic to citrus hosts tested. Several isolates were non-pathogenic or only moderately virulent to the citrus hosts tested even though they could produce elsinochromes in culture, a phenotype not previously described in Florida.     

柑桔园生草栽培的生态效应研究

柑桔园生草栽培的生态效应研究李国怀章文才刘继红胡德文（华中农业大学园艺系,武汉４３００７０）ＳｔｕｄｉｅｓｏｆＥｃｏｌｏｇｉｃａｌＥｆｅｃｔｓｏｆＳｏｄＣｕｌｔｕｒｅｉｎＣｉｔｒｕｓＯｒｃｈａｒｄ．ＬｉＧｕｏｈｕａｉ,ＺｈａｎｇＷｅｎｃａｉ,ＬｉｕＪ...     

Ca2+信号系统对低温下柑橘膜脂过氧化和抗氧化酶的影响

研究不同Ca2+处理对低温下柑橘愈伤组织膜脂过氧化和抗氧化酶的变化。结果表明,一定低浓度的Ca2+(5mmol/L)能明显减少柑橘愈伤组织膜伤害率和膜脂过氧化产物MDA的积累,增加渗透调节物质可溶性蛋白质的含量,提高膜保护性酶SOD和POD的活性,从而增强柑橘的抗寒性。采用Ca2+螯合剂乙二醇双乙胺醚-N,N′-四乙酸(ethylene glycol-bis-β-aminoethylether-N,N′-tetraacetic acid,EGTA)或钙调素(cal mod-ulin,Ca M)拮抗剂三氟拉嗪(trifluoperazine,TFP)处理会增加膜伤害率和MDA的积累,减少可溶性蛋白质的合成,降低SOD和POD的活性。说明钙信号系统参与调节柑橘抗寒中膜脂过氧化和保护性酶等生理生化反应。     

In vitro tetraploidy induction in Mexican lime and sour orange and evaluation of their morphological and physiological characteristics

Plant Cell, Tissue and Organ Culture (PCTOC) - In this research, the production of superior genotypes via the polyploidy induction method in two citrus species involved the tissue culture of stem...     

Citrus tissue culture employing vegetative explants

Citrus being a number one fruit of the world due to its high nutritional value, huge production of fruits and fruit products, the citrus industry may be considered a major fruit industry. Though citrus orchard area in India is comparable to USA, the produce is far less, while its export is nil. Biotechnology has played an outstanding role in boosting the citrus industry, e.g., in Spain, which is now the biggest exporter of citrus fruit with the application of micrografting. Amongst the fruit trees, perhaps the maximum tissue culture research has been done in citrus during the past four decades, however, the results of practical value are meagre. The shortfalls in citrus tissue culture research and some advancements made in this direction along with bright prospects are highlighted, restricting the review to vegetative explants only. Whilst utilization of nucellar embryogenesis is limited to rootstocks, the other aspects, like, regeneration and proliferation of shoot meristems measuring 200 microm in length--a global breakthrough--of two commercially important scion species, Citrus aurantifolia and C. sinensis and an important rootstock, C. limonia, improvement of micrografting technique, cloning of the same two scion species as well as some Indian rootstock species, employing nodal stem segments of mature trees, of immense practical value have been elaborated. A rare phenomenon of shift in the morphogenetic pattern of differentiation from shoot bud differentiation to embryoid formation occurred during the long-term culture of stem callus of C. grandis. Stem callus-regenerated plants of C. aurantifolia, C. sinensis and C. grandis showed variation in their ploidy levels and a somaclonal variant of C. sinensis, which produced seedless fruits was isolated. Tailoring of rooting in microshoots to a tap root-like system by changing the inorganic salt composition of the rooting medium, resulting in 100% transplant success, and germplasm preservation through normal growth culture of shoots of C grandis without loss of regeneration capacity during 31 years, observed so far, are some other significant results. Plants of C. aurantifolia and C. sinensis raised from shoot meristem and micrografting were grown in a nethouse and those from nodal stem segments in the field along with the in vitro-raised plants of rootstocks, namely, C. jambhiri, C. karna and C. limonia. All the plants showed normal healthy growth. Significantly enough, the meristem regenerated plants of C. aurantifolia attained the reproductive phase just in 1 year of transplantation to soil similar to those raised from nodal stem segments of mature trees, which also produced normal fruits in the subsequent year while growing under field conditions. Thus, a significant fundamental concept of a maturity factor, carried over through as small a shoot meristem as 200 microm in length to cloned plants has been demonstrated. The concept is of far-reaching significance in citrus industry besides production of pathogen-free orchards.