茶藨生柱锈菌锈孢子形态分化研究

本研究从我国辽宁、云南、四川、山西等4省6地的五针松疱锈病发病林分中采集茶藨生柱锈菌锈孢子,对其形态分化进行了系统的研究。结果表明:我国茶藨生柱锈菌在形态上存在分化现象。锈孢子大小为21.10~40.10×14.97~29.40μm之间,变幅较大,其中辽宁清原红松上的锈孢子最小(18.72~30.73×16.04~24.07μm)。锈孢子的超微形态结构也存在差异,红松上的锈孢子的疣突基部和顶部基本一样宽,而华山松上锈孢子疣突的基部比顶部稍宽;不同病区华山松疱锈菌环纹数、疣突的排列和间距不一。寄主在病原菌的变异中发挥着积极的促进作用。     

华山松疱锈病菌锈孢子萌发试验

华山松疱锈病病原菌ＣｒｏｎａｒｔｉｕｍｒｉｂｉｃｏｌａＪ．Ｃ，ＦｉｃｈｅｒｅｘＲａｂｅｈｏｒｓｔ的锈孢子在灭菌水、２％葡萄糖液、２％蔗糖液及２％麦芽糖液中均能萌发。萌发的最适温度为１０－１５℃，ｐＨ为６－７，ＲＨ为２５％－７５％，光暗交替较之全暗条件更利于锈孢子的萌发。锈子器自然破裂放出的锈孢子较未裂锈子器中的锈孢子萌发率高１－２倍。     

华山松疱锈病菌锈孢子萌发试验

华山松疱锈病病原菌Ｃｒｏｎａｒｔｉｕｍ ｒｉｂｉｃｏｌａ Ｊ．Ｃ．Ｆｉｃｈｅｒ ｅｘ Ｒａｂｅｈｏｒｓｔ的锈孢子在灭菌水、２％葡萄糖液、２％蔗糖液及２％麦芽糖液中均能萌发。萌发的最适温度为１０－１５℃，ｐＨ为６－７，ＲＨ为２５％－７５％。光暗交替较之全暗条件更利于锈孢子的萌发。锈子器自然破裂放出的锈孢子较未裂锈子器中的锈孢子萌发率高１￣２倍。     

茶藨生柱锈菌寄主遗传多样性研究

运用随机扩增多态DNA (RAPD)标记对分布于我国4省6病区63份茶藨生柱锈菌寄主红松和华山松进行遗传多样性分析.用6个随机引物对寄主松针进行PCR扩增,共得到138个DNA位点,其中多态位点117个,多态位点比率为84.78%,RAPD的Shannon指数遗传多样性为0.315 5,RAPD的Nei指数基因分化系数为0.525 5.不同来源寄主的遗传多态性规律顺序:辽宁清原红松＞云南洱源华山松＞山西沁水华山松＞云南巧家华山松＞四川广元华山松＞云南东川华山松.从RAPD聚类分析树状图可以看出,先将63个松针样品分成2个不同的RAPD组群(红松组群和华山松组群),然后又将不同地理来源的华山松组群按地理区域分成5个亚群,同一采集的华山松亚群中又分成感病组和抗病组.研究表明,种间的遗传多样性是由种的遗传属性所决定的,而地理因素只是影响种内遗传多样性的一个因子.     

茶藨生柱锈菌致病性分化的初步研究

采用交互接种的方法对华山松疱锈病、红松疱锈病的病原菌茶藨生柱锈菌的致病性分化进行了研究。结果表明:(1)红松疱锈病的病原菌锈孢子只能侵染其本地的转主寄主植物东北茶藨子;(2)华山松疱锈病的病原菌锈孢子能转主侵染多种不同地区的茶藨子植物;(3)所有华山松疱锈病病原菌的锈孢子均不能转主侵染东北茶藨子;(4)初步认定马先蒿属植物不是华山松疱锈病病原菌的转主寄主。     

菊花白锈病菌冬孢子萌发的生物学特性

菊花(Dendranthema × grandiflorum(Ramat) Kitam.)是中国传统名花,其花色丰富,花型各异,深受人们的喜爱.同时菊花也是世界四大切花之一,在国际花卉贸易中占有重要的经济地位.     

松杨栅锈菌担孢子萌发的数学模型研究

由松杨栅锈菌Melampsora larici-populina Kleb.引起的落叶松—青杨叶锈病是一种广泛分布于苗圃和造林地的林木叶部病害,严重影响苗木的成活率。本研究根据线性拟合求出离散点间满足的相互关系,用最小二乘法求一个形如y=a+bx2的经验公式,使它与观测数据拟合,得到担孢子萌发模型:f(x)=a1x2+a2x+a3,为该病的流行病学、预测预报研究提供科学依据。     

松针锈病症状类型及锈孢子表面结构在分类学上的意义

作者通过对东北不同地区不同松树松针锈病Ｃｏｌｅｏｓｐｏｒｉｕｍｓｐｐ．的调查发现,单维松上可表现１种症状类型,双维松上可表现出３种症状类型;锈孢子表面纹饰与这４种症状类型有内在联系,这在研究鞘锈菌的系统发育和分类学上具有重要意义。     

小兴安岭地区东北茶藨子生物学特性观察

以伊春带岭当地的野生东北茶藨子为研究对象,通过对其的物候观测,来达到深入了解伊春带岭东北茶藨子的生物学特征和生态适应性,从而为该野生资源的引种栽培及开发利用提供科学依据。     

人参锈腐病病原菌生物学特性研究

为探究引起人参锈腐病致病菌的生物学特性,以人参锈腐病病株根部分离的菌株为试材,采用菌丝生长速率法研究了不同培养基、温度、p H值、光照、碳、氮条件对该菌菌丝生长的影响及其致死温度。结果表明:最适合该菌生长的培养基为改良马丁氏,其次是PDA;最适温度为20℃;最适生长pH值为7;在12 h光暗交替条件下菌丝生长最快;最适菌落生长碳源为甘露醇;最适氮源为硝酸钾;致死温度55℃。研究结果可为人参锈腐病发病规律的研究和病害防治提供科学依据。     

Finnish Cronartium ribicola does not infect alternate hosts of Cronartium flaccidum

Susceptibility of the main alternate hosts of Cronartium flaccidum, Vincetoxicum spp. and Melampyrum spp., to C. ribicola was investigated by artificial inoculations on detached leaves in the laboratory and on whole plants in the greenhouse. Neither uredinia nor telia developed on the leaves of either Vincetoxicum hirundinaria, Vincetoxicum nigrum, Melampyrum sylvaticum, Melampyrum pratense, Melampyrum nemorosum, Melampyrum arvense, Melampyrum cristatum or Melampyrum polonicum following inoculation by the 26 aeciospore sources collected from Pinus strobus, Pinus monticola, Pinus flexilis and Pinus peuce in 2000–2003. The results suggest that Finnish C. ribicola does not infect the main alternate hosts of C. flaccidum. Cronartium ribicola and C. flaccidum can thus be identified reliably by inoculations on their main alternate hosts.     

红松疱锈病病株的鉴别方法

根据红松疱锈病的危害症状及生物学特性，介绍了孢囊、蜜滴、树皮龟裂、虫瘿、团状树冠5种鉴别红松疱锈病株的方法。     

Effect of Cronartium quercuum on cell chromosome ofXingkai Lake pine

lntroductionXingkaiLakepine(PinustakahassiNakai)distributedoveraIittleregionbetweenSuifenRiverandXingkaiLakeinNortheastofChina.lnrecentyears,XingkaiLakepineisheavilyinfectedbyCronarfaimquercuum,theincidenceofthisdiseasehasincreasedto98%insomefof6stareas.Thediseasegreatlyaffectedtree'sfruitgrowingandnaturaIregeneration.Ac-cordingtotheinvestigation,each2~3year-oldhealthytreehas13oconesonaverage,itsnaturalregenerationrateis45%forhealthyforest,whiIethatofIightinfectedforestandnewlyinjectedfo…     

Variation of virulence of white pine blister rust

According to the literature the following evidence suggests racial variation in white pine blister rust: changes over site in general level of resistance; interaction of needle spot color types with crosses of western white pine; neutralization of specific resistance reactions; bark reactions and normal cankers on the same tree.     

A Reappraisal of the Importance of Cronartium ribicola on Pinus strobus in Great Britain

Because of the possibility of serious infection by Cronartiumribicola (White pine blister rust), Pinus strobus, the Weymouthpine, is now very rarely planted in British forests. An assessment,in 1962, in a number of experimental forest plots of P. strobusestablished in 1953 and 1954 showed that initial infection ofthe trees while growing in the nursery may be an important factorin causing later damage and losses in the forest. The resultsalso indicated that the risk of infection in plantation cropsas a result of spore dispersal from black currants in the localityis much lower than is generally thought. It is suggested thatif P. strobus is raised in nurseries which are relatively isolatedfrom currants and if protective chemical spraying against thedisease in the nursery is carried out, the incidence of infectionin plantations at least half a mile from the nearest currantsis likely to be low. The disease cannot spread within a pinecrop by direct transmission from tree to tree.     

Epicuticular wax content of western white pine is involved in Cronartium ribicola resistance

The introduction of Cronartium ribicola, the causative agent of white pine blister rust, has been devastating for white pines in North America, including western white pine. Among the observed partial resistance responses to white pine blister rust is a mechanism referred to as difficult-to-infect (DI), which is characterized by lower frequency of infection spots on needles and a lower incidence of branch and stem cankers than susceptible host plants. Parents with the DI trait were selected and bred to produce nine full-sib families. Progeny were propagated and cloned using in vitro techniques in controlled environmental conditions. Explants were inoculated with a single strain of C. ribicola and characterized by using a disease assessment index (DAI), which was used to compare DI full-sib families to several other full-sib families (from Idaho) selected for other partial resistance traits. Most DI families had significantly lower DAI scores and higher epicuticular wax content. When the wax was removed from the surface of needles, the DAI of all full-sib families increased. Scanning electron microscopy revealed that stomata in DI full-sib families are mostly occluded by epicuticular wax. The results of this study suggest that the DI resistance mechanism of western white pine is related to needle surface epicuticular wax, which likely hinders the penetration of stomata by fungal hyphae. The occurrence and magnitude of this trait in the breeding population remains unknown, and special assessment technique for large-scale screening will have to be developed.     

Anatomical and cellular responses of Pinus monticola stem tissues to invasion by Cronartium ribicola

White pine blister rust (Cronartium ribicola) causes extensive damage to white pines and their associated ecosystems across North America. The anatomical and cellular characteristics of C. ribicola colonization in Pinus monticola branch and stem tissues were studied as a basis for understanding host tree reactions that may be related to resistance. Samples examined showed typical fusiform swelling and some had produced aecia. The reaction of phloem and xylem tissues was compared with non-infected tissue using light and electron microscopy. Cortical parenchyma and phloem polyphenolic parenchyma cells underwent mitotic division, cell swelling, and ca sixfold greater accumulation of phenolic compounds in colonized vs. control stems. In the cortex and secondary phloem, haustoria were common in parenchymatous cells, and hyphae were abundant in the intercellular spaces, but cell death was rare, unless aecia had ruptured the stem cortex. Hyphae were also common in xylem rays, tracheids and between tracheids. Disease-induced changes in the cambial zone included development of cambium-derived xylem traumatic resin ducts. Results demonstrate that diverse host defence responses were activated in the bark of apparently susceptible trees, but lack of mechanical damage by C. ribicola to the phenol-containing host cells and the resin duct system allowed extensive colonization and development of aecia despite elicitation of these stem defences. Interactions between P. monticola and C. ribicola are discussed and compared with other conifer–fungus pathosystems.