过氧化氢酶基因CsKat01与柑橘溃疡病相关性分析

为了探究过氧化氢酶基因CsKat01在柑橘抵御溃疡病过程中的作用,对感病品种'晚锦橙'和抗病品种'四季橘'中CsKat01进行了生物信息和表达分析,并探究了溃疡病菌接种处理后两品种中CAT酶活性和H2O2含量的关系.克隆CsKat01的编码序列并对该基因及其编码蛋白进行结构和功能分析,发现CsKat01编码框全长为1 ...     

叶片微形态结构特征与柑橘溃疡病抗性相关性研究

为了研究叶片微结构特征与柑橘溃疡病抗性的关系。选用罗浮金柑、新生系3号椪柑、纽荷尔脐橙及星露比葡萄柚这四个分别被认为是对柑橘溃疡病具有高抗、抗、耐和高感特性的品种,通过涂抹接种法来在实验室验证其抗病性;采用扫描电镜及树脂包埋半薄切片等技术对上述品种的成熟叶片下表皮气孔及叶片显微解剖结构进行观察测量;将健康叶片浸泡在菌液中,采用细菌分离法来观察同样条件下通过气孔进入不同柑橘品种叶片体内的活细菌数。结果：四个品种对溃疡病抗性存在显著差异;不同品种间气孔密度、气孔大小、叶片厚度、栅栏组织厚度、海绵组织厚度、下皮层厚度也存在差异,其中气孔密度差异达到极显著;健康叶片浸泡接种溃疡病后,分离到的单菌落数的顺序依次是星露比葡萄柚>纽荷尔甜橙>新生系3号碰柑>罗浮金柑。因此,气孔密度对柑橘品种抗病性的解释量极高。     

Symptom development of the resinous stem canker caused by inoculation withCistella japonica ontoChamaecyparis obtusa

Cistella japonica was inoculated onto the stems of youngChamaecyparis obtusa trees, and the development of external and internal symptoms was investigated for five years. Most lesions started exuding resin from May to July during the first growing season after inoculation, while a few lesions started exuding resin during the second growing season. Resin exudation lasted for two successive years on most lesions, and during successive three, four, or five years on some lesions. Resin exuded excessively in the secondary phloem of the lesions and resin cysts frequently developed there. The lesions where cambial tissue was necrosed occupied 18% of all the lesions and the resinous areas expanded to a larger size than those where resin simply exuded in the phloem.Ci. japonica was reisolated from some inoculated lesion tissues at a high frequency. The isolation frequency of the fungus from some lesion tissues two and more years later was zero or low and that ofCryptosporiopsis abietina was high. This work was supported by a grant from the Forest Agency of the Japanese Government.     

The Influence of Fungicide Sprays on Infection Of Apple cv. Bramley's Seedling By Nectria galligena

In 1990, a long-term trial was initiated by planting young apple trees, cv. Bramley's Seedling, inoculated, at single sites in the leader shoots, with Nectria galligena. The effect of spring–summer and autumn fungicide spray programmes, applied during 1991–1993, on the development of new cankers was assessed up to May 1994. Spring–summer fungicide programmes, applied as for the control of apple scab, reduced numbers of new cankers by between 65% and 76% compared with the untreated control. Sterol demethylation inhibiting fungicides (hexaconazole, myclobutanil, penconazole) had a similar effect on canker to dithianon. Autumn application of copper oxychloride at 5% and 50% leaf-fall further reduced numbers of new cankers. The combination of a spring–summer benzimidazole (carbendazim or thiophanate-methyl) with a scab fungicide (dithianon) and autumn copper oxychloride did not improve canker control compared with applying copper oxychloride after spring–summer myclobutanil+mancozeb. The percentage of fruit which developed rots in long-term storage was decreased by spring–summer benzimidazole application, but not by other fungicide programmes even those which achieved similar levels of canker control.     

银鹊树溃疡病病原菌的研究

通过分离培养、人工接种和病原鉴定,确定银鹊树溃疡病的病原为茄腐皮镰孢菌(Fusarium solani(Martius)App. etWr.),有性世代未见。病菌菌丝生长适温25～33℃,低于10℃、高于38℃均不能生长,且大孢子的产生量与温度有关;对pH值要求不严,在pH为2～10时均可生长;其菌丝在PDA 和马丁氏培养基上生长最佳,大型分生孢子产生量多,在银鹊叶煎汁和清水洋菜培养基上生长一般。在利用碳源上以葡萄糖、蔗糖和鼠李糖生长最好,半乳糖、果糖次之,木糖最差。分生孢子萌发的适宜温度为25～30℃,大孢子萌发以10% 银鹊叶煎汁及2% 葡萄糖液最好(达98% ),6h 达到萌发盛期;小孢子10h为萌发盛期,且在上述两种营养液中的萌发率仅为40.3% 和36.0% 。     

Differentiation of Seiridium species associated with virulent cankers on cypress in the Mediterraneanregion by PCR-SSCP

A rapid and sensitive method was developed to discriminate between Seiridium cardinale and Seiridium cupressi , the fungi causing severe cankers on common cypress in the Mediterranean area. The method amplified sequence variants in the ITS2 region of ribosomal DNA using the polymerase chain reaction (PCR), followed by polyacrylamide gel electrophoresis, to reveal single-strand conformation polymorphism (SSCP) between the two species. The greatest separation pattern was obtained with a gel matrix containing 7–10% formamide and 3–5% glycerol under optimized running conditions, which were found to be 30–40 V at 4–5°C for 4–8 h. Sequence homology among isolates within each of the two species caused no mobility shifts, with all isolates displaying the same migration pattern. A few base differences between S. cardinale and S. cupressi caused markedly different migration patterns, allowing differentiation of the two pathogens. Differences between these fungi at the genetic level are consistent with known data on morphological, physiological and pathogenic characteristics. SSCP analysis constitutes a rapid and easy-to-perform method by which to recognize and distinguish closely related organisms, and has considerable potential for use in diagnosis and taxonomy.     

割面宝控制橡胶树树皮溃疡病扩展试验

割面宝是一种新型橡胶树割面保护剂。通过在橡胶品系RRIM60 0 ,2～ 3年生离体和活体材料上的试验 ,对橡胶割面条溃疡病 (病原Phytophthoracitrophthota)病斑扩展有显著的抑制作用 ,抑制能力和生产上使用的有效农药治疡灵相近 ,差异不显著     

基于栽培管理措施的猕猴桃细菌性溃疡病防治技术

对陕西猕猴桃种植区的栽培管理技术措施与猕猴桃枝干溃疡病发病关系的研究发现,栽培管理措施及水平直接影响溃疡病的发生程度,管理精细的果园发病较轻.为有效控制病害,冬季修剪应在落叶后至元月中旬之间进行;冬灌不能晚于11月底,春灌不早于4月;合理施肥,控制春季萌芽的早晚、伤流的多少和树木生长势,降低病害发生程度.     

苹果树腐烂病菌分生孢子萌发及其影响条件研究

由于苹果树腐烂病菌分生孢子在清水中不能萌发,因此采用在PDA培养基上涂布孢子悬浮液使其萌发的方法,研究了不同温度、湿度、pH及光照对其分生孢子萌发的影响。结果表明,苹果树腐烂病菌分生孢子在15~28℃的温度范围内都可以萌发,最佳的萌发温度为25~28℃。分生孢子的萌发需要饱和的相对湿度。分生孢子萌发的酸碱度范围为pH 2.14~7.10,最适pH为5.10~6.10。营养条件对腐烂病菌分生孢子的萌发有明显的影响。虽然在连续黑暗条件下,腐烂病菌分生孢子的萌发率较连续光照和光暗交替条件下略高,但各种光照处理对孢子萌发率的影响不明显。     

桃树溃疡病侵染循环的研究

本文报道了昆明地区由扁桃壳梭孢(Fusicoccum amygdali Dalacr. )侵染而引起的桃溃疡病。这一病害主要发生在桃树一年生枝条上。在叶痕和当年生枝条基部形成深褐色病斑。据1987年观察,病害在6月初开始发生,到10月发展至高峰。病原菌于11月进入休眠期。接种试验表明,病原菌只能从寄主受伤组织侵入,潜育期约为10天。研究结果认为这一病害具有潜伏侵染现象。病原菌以菌丝体和分生孢子在病枝上越冬,也能在果园内脱落在地面的病枝上存活。分生孢子在雨季内随雨滴飞溅大量传播,以7月后期至8月初数量最多。