ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00327.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryRhizoctoniafungi were isolated from the roots of 2‐year‐old nursery‐grown Norway‐spruce seedlings displaying root‐dieback symptoms. The most frequently isolated species, a uninucleateRhizoctoniasp., was found to co‐exist with binucleateRhizoctoniain the same root system of several seedlings. All the uninucleate isolates anastomosed with each other forming a single anastomosis group with common cultural characteristics. BinucleateRhizoctoniaisolates were divided into several, morphologically dissimilar anastomosis groups (AG‐I, R. spp.). In a pathogenicity test under sterile conditions, isolates belonging to the uninucleateRhizoctoniasp. infected all root regions, particularly the root tips, resulting in a stunted root‐system morphology, as was also observed in the isolation material.BinucleateRhizoctoniaspp. colonized only basal root regions, occasionally infecting cortical cells with monilioid hyphae, and had no effect

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00328.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe pathogenicity ofColletotrichum dematiumwas evaluated as the agent causing post‐emergence damping‐off of current‐year beech (Fagus crenata) seedlings. Current‐year beech seedlings inoculated withC. dematiumdied within 20 days after both wound and non‐wound inoculation, indicating that this fungus is pathogenic to current‐year seedlings.C. dematiumwas frequently isolated from hypocotyls exhibiting damping‐off at five different sites. The incidence of isolation was high and little variation occurred between sites and years.C. dematiumwas also detected in all litter samples examined although the incidence of detection differed depending on sites and/or detection methods.These results strongly indicate thatC. dematiumplays an important role in rapid seedling death during the early stages of beech

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00329.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryHaustorial morphology of the cone‐rust pathogen,C. conigenum, was investigated among naturally infected female strobili of three Guatemalan pines,P. maximinoi, P. pseudostrobus, andP. oocarpa. Among the three pine species, haustorial shapes and sizes were more variable inP. maximinoiandP. oocarpathan inP. pseudostrobus. The haustorial shapes and sizes were more variable in parenchyma cells of the cortex, xylem, and pith than in the cells in the phloem, xylem rays, and tracheids. The haustoria were also present in larger numbers in the parenchyma cells of the cortex, xylem, and pith than in phloem parenchyma cells and tracheids. In living cells, the tips of some haustoria were appressed to the host nucle

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00330.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryGremmeniellaabietinaisolates fromPinus contortain northern Sweden produced, in vitro, shorter conidia with fewer septa compared with isolates fromPinus sylvestrisin the southern part of the country. After mycelial inoculation of shoots withG. abietinaisolates from both host species, the resulting necroses were longer inP. sylvestristhan inP. contorta. Keeping seedlings in artificial mild winter climate or detaching shoots from the seedling before inoculation caused longer necroses. No host specificity in colonization was found. Isolates fromP. sylvestriscaused longer necroses than did isolates fromP. contorta, and both types of isolates caused longer necroses inP. sylvestristhan inP. contorta. The differences found between the twoG. abietinapopulations probably reflect regional variation in the fungus.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00331.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe occurrence and accumulation of β‐1, 3‐glucanase and chitinase in seedling roots of spruce (Picea abies) following challenge by the root‐rot pathogenHeterobasidion annosumwere studied. Chitinase activity increased 2–3 fold following inoculation, whereas no significant increase in the activity levels of glucanase was recorded during infection. With TEM immunogold labelling, the enzymes were localized in protein aggregates in host tissues and in the cell walls of intercellular hyphae. Gold particles were sparse and irregularly distributed within host‐cell walls. Only minor labelling was observed on hyphal walls coated with electron‐dense materials. The labelling intensity increased with infection time and was always higher than in non‐infected seedling roots. When this experiment was repeated using root samples inoculated with the saprophytePhlebiopsis gigantea, a similar labelling pattern was observed. The cross reactivity of antisera raised against sugar‐beet chitinase and glucanase with spruceroot enzyme extracts was demonstrated using dot‐blo

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00332.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryEpicoccum purpurascenswas applied to stem wounds of Norway spruce for a preliminary assessment of its potential as a biological protection against decay fungi.E. purpurascenshad a significant influence on the composition of the mycoflora of the wounds, analysed 8 months after inoculation.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00333.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb00334.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY