The invasion of native forest by Phytophthora cinnamomi. I. Brisbane Ranges, Victoria

1971 ◽  
Vol 19 (3) ◽  
pp. 281 ◽  
Author(s):  
GM Weste ◽  
P Taylor
Keyword(s):  
Water Stress ◽  
Phytophthora Cinnamomi ◽  
Eucalyptus Species ◽  
Native Forest ◽  
Symptom Expression ◽  
Root Pathogen ◽  
Disease Symptoms ◽  
Sclerophyll Forest ◽  
Drainage Channels

Disease within an open sclerophyll forest dominated by Eucalyptus species of relatively low stature (15-20 m) was shown to be caused by Phytophthora cinnamomi Rands, an introduced root pathogen. Diseased sites were mapped and measured. The rate of advance of the pathogen over a period of 5 months was calculated at 4 m per month through moderately drained soils compared with 7 m per month through soils subject to waterlogging. Areas showing disease symptoms increased from 10.8 to 90%, the major extensions occurring along gullies. Spread of the fungus was associated with road-making activities, waterlogging, and the presence of drainage channels. Symptom expression in the different species was studied and shown to be similar to that associated with water stress. Most of the 42 species comprising the woody flora were susceptible to the disease, those particularly susceptible including the dominants. During a period of 8 months mortalities occurred in 50% of the species. Grasses, sedges, and Eucalyptus goniocalyx appeared to be field-resistant, but were uncommon in the Aora of the sites studied.

The Invasion of Native Forest by Phytophthora cinnamomi. II. Post-Infection Vegetation Patterns, Regeneration, Decline in Inoculum and Attempted Control

1973 ◽  
Vol 21 (1) ◽  
pp. 13 ◽  
Author(s):  
G Weste ◽  
D Cooke ◽  
P Taylor
Keyword(s):  
Phytophthora Cinnamomi ◽  
Soil Disturbance ◽  
Vegetation Patterns ◽  
Native Forest ◽  
Disease Symptoms ◽  
Sclerophyll Forest ◽  
Successful Control ◽  
Woody Shrubs ◽  
Spread Of Infection ◽  
Barrier Zone

Further investigations of die-back in sclerophyll forest have shown that the disease continued to spread, averaging 171 m per year over periods of 3 years. Soil disturbance and gravel removal did not result in disease when no P. cinnamomi was present. P. cinnamomi was isolated from areas showing disease symptoms, but not from unaffected areas. The pathogen was confined to the A horizon of the soil and did not penetrate the clay or B horizon. Susceptibility of eucalypts was experi- mentally demonstrated at germination, at the seedling stage, and at maturity. More than 40% of mature stringybarks (of three species) were killed on some severely diseased sites. The eucalypts of the area were rated in order of susceptibility or tolerance to the pathogen. A decline in the disease potential of infected soil with time was demonstrated, and was associated with decreased population density of the pathogen. Changes in both type and composition of the plant community were noted. The sclerophyll forest with its woody understorey became a grassy woodland. A number of woody shrubs disappeared and a variety of herbs, such as grasses, bulbs, and composites, colonized the space made available by the death of woody shrubs and die-back of the eucalypt canopy. The most successful control of the disease was achieved by injecting infected areas with Vapam. This killed everything, and a barrier zone 4 m wide injected with Vapam prevented the spread of infection over a period of 18 months.

The Invasion of Native Forest by Phytophthora cinnamomi. III. Threat to the National Park, Wilson's Promontory, Victoria

1973 ◽  
Vol 21 (1) ◽  
pp. 31 ◽  
Author(s):  
G Weste ◽  
C Law
Keyword(s):  
Plant Community ◽  
National Park ◽  
Phytophthora Cinnamomi ◽  
Free Water ◽  
Native Forest ◽  
Symptom Expression ◽  
Field Observations ◽  
Ecological Significance ◽  
Maximum Root ◽  
Old Trees

Diseased vegetation was first reported from the northern slopes of the Vereker Range at Wilson's Promontory National Park in September 1970. Phytophthora cinnamomi was isolated from plants in diseased areas but not from unaffected localities. The pathogen has since invaded three types of plant community-dry sclerophyll woodland, heaths, and swamps-and can be isolated at all depths to 80 cm in deep sands. High inoculum potentials are found at depths of maximum root concentration, i.e, to about 32 cm. Except where free water occurs, the rate of extension of the disease is slow. Dominants of both tree and shrub strata are susceptible and have been killed. Highly susceptible shrubs of the understorey, such as Xanthorrhoea australis and Isopogon ceratophyllus, are destroyed first. These are followed 6-12 months later by less susceptible shrubs, and at least 12 months later symptoms appear in trees. This variation in time may be responsible for the characteristic mosaic appearance of diseased areas. Inoculation experiments on 9-month-old trees of Banksia serrata and Eucalyptus obliqua confirmed field observations of susceptibility and symptom expression. The origin of the disease at Wilson's Promontory and its ecological significance are examined. Experiments in control of the pathogen are reported and recommendations discussed for control within the National Park.

The Distribution of Phytophthora cinnamomi Rands at Two Sites in Southern Western Australia and at Durras in South-Eastern New South Wales.

1982 ◽  
Vol 30 (2) ◽  
pp. 139 ◽  
Author(s):  
WM Blowes ◽  
WA Heather ◽  
N Malajczuk ◽  
SR Shea
Keyword(s):  
Western Australia ◽  
Phytophthora Cinnamomi ◽  
New South ◽  
New South Wales ◽  
Native Forest ◽  
Prevention Strategies ◽  
South Eastern ◽  
Isolation Techniques ◽  
South Wales ◽  
Western Australian

Native forest at Durras in south-eastern New South Wales and Jarrahdale in south-western Western Australia was examined for the presence of Phytophthora cinnamomi by two sampling and isolation techniques. With the lupin seeding baiting technique, randomly selected samples of soil and fine roots collected from the New South Wales site yielded P. cinnamomi when baited, while similar baiting of comparable samples from Western Australia failed. Direct plating of samples of upper roots and root collars of recently dead Banksia grandis from Western Australian sites yielded P. cinnamomi, while this organism was not isolated from comparable samples of chlorotic Macrozamia communis collected at the New South Wales site. The results suggest that the form of occurrence of P. cinnamomi and its association with disease in Australia vary in different situations. Viewing each situation independently might ensure the adoption of control/prevention strategies appropriate to all.

Proteomic analyses unraveling water stress response in two Eucalyptus species originating from contrasting environments for aridity

2020 ◽  
Vol 47 (7) ◽  
pp. 5191-5205
Author(s):  
Rayana de Sá Martins ◽  
José Marcio Rocha Faria ◽  
Bruno César Rossini ◽  
Celso Luís Marino ◽  
Lucilene Delazari dos Santos ◽  
...  
Keyword(s):  
Water Stress ◽  
Stress Response ◽  
Eucalyptus Species ◽  
Proteomic Analyses

Vegetation Changes as a Result of Invasion of Forest on Krasnozem by Phytophthora cinnamomi

1980 ◽  
Vol 28 (2) ◽  
pp. 139 ◽  
Author(s):  
G Weste
Keyword(s):  
Pinus Radiata ◽  
Phytophthora Cinnamomi ◽  
First Year ◽  
Acacia Dealbata ◽  
Sclerophyll Forest ◽  
Lower Height ◽  
Leaf Spot Fungus ◽  
Future Status ◽  
Reduced Water ◽  
Increased Susceptibility

Disease caused by Phytophthora cinnamomi was studied for 5 years in native and planted forest growing on krasnozem in the northern foothills of the Great Dividing Range at Narbethong, 100 km northwest of Melbourne. Changes in species composition were recorded for three sites carrying mature dry sclerophyll forest of Eucalyptus obliqua and Eucalyptus radiata, young plantations of E. obliqua, and young plantations of Pinus radiata. The mature ecualypts were diseased in 1974 and now are gradually dying. The young E. obliqua showed greater resistance than the older trees to the pathogen but infected trees were characterized by lower height, small leaves with reduced water potential, and an increased susceptibility to the leaf spot fungus Aulographina eucalypti. Susceptible understorey species such as Tetratheca ciliata and Epacris impressa died, but seedling regeneration of these has since occurred on one site. No species has disappeared from all three sites but T. ciliata and Daviesia latifolia almost disappeared from site 2, and the total number of plants was reduced. Species such as Leptospermum juniperinum and Platylobium formosum developed fluctuating cycles of chlorosis and die-back followed by either recovery or death. Resistant plants such as sedges, grasses and Acacia dealbata invaded the diseased forest. During the first year of the investigation 13% of the 4-year-old Pinus radiata died, but this particular site was well drained, warmer and drier than the others and the surviving pines later grew vigorously and crowded out other species. Symptoms are no longer evident on this site. The future status of the mature forest and the probable effects of disease on the young E. obliqua plantation are discussed.

Pathogenic Variability in Australian Isolates of Phytophthora cinnamomi

1993 ◽  
Vol 41 (6) ◽  
pp. 721 ◽  
Author(s):  
MJ Dudzinski ◽  
KM Old ◽  
RJ Gibbs
Keyword(s):  
Phytophthora Cinnamomi ◽  
Growth Period ◽  
Species Variation ◽  
Eucalyptus Marginata ◽  
Disease Symptoms ◽  
Horticultural Crops ◽  
Damage Reduction ◽  
Single Clone ◽  
Pathogenic Variability ◽  
Stable Characteristic

Forty-two isolates of Phytophthora cinnamomi were obtained from native vegetation and horticultural crops within Australia. They represented a broad spectrum of geographical and host origins, both mating types, and all identified Australian isozyme genotypes. All isolates were tested for their pathogenicity to a single clone of Eucalyptus marginata by inoculation of soil in which plants were growing. Differences in pathogenicity were expressed as extent of root damage, reduction of plant growth, period to first visible disease symptoms and time to plant death. Significant variation between isolates was detected. Pathogenicity was unrelated to mating type and isozyme properties. A subset of these 42 isolates encompassing a range of virulence gave generally consistent rankings for pathogenicity variates when re-inoculated twice into plants derived from the original clone. This suggests that pathogenicity is a relatively stable characteristic. Detection of differences in susceptibility to P. cinnamomi between three selected E. marginata. clones was influenced by the pathogenicity of isolates. Only the more pathogenic isolates were useful in this regard. Seedling stems of five eucalypt species were inoculated with virulent and less virulent isolates of P. cinnamomi. This method detected variation in both pathogenicity in the fungus and susceptibility in the host species. Variation in pathogenicity within Australian populations of P. cinnamomi should be taken into account by the choice of isolates of proven virulence when selecting for resistance in trees and other woody hosts.

Herbivore damage, resource richness and putative defences in juvenile versus adult Eucalyptus leaves

2005 ◽  
Vol 53 (1) ◽  
pp. 33 ◽  
Author(s):  
Emma K. Gras ◽  
Jennifer Read ◽  
Chantal T. Mach ◽  
Gordon D. Sanson ◽  
Fiona J. Clissold
Keyword(s):  
Dry Weight ◽  
Eucalyptus Species ◽  
Native Forest ◽  
Leaf Toughness ◽  
Resource Concentration ◽  
Mature Adult ◽  
Unit Leaf ◽  
Eastern Australia ◽  
Significant Difference ◽  
Different Levels

Eucalyptus species often show marked differences in morphology and ecophysiology between adult and juvenile leaves. Given these differences, it was hypothesised that juvenile and adult leaves would present different levels of resources to a herbivore, and potentially different levels of putative anti-herbivore defences. This hypothesis was tested in some eucalypts growing in native forest in south-eastern Australia. There were no significant differences in levels of water, protein or carbohydrates (per unit dry weight) between mature adult and juvenile leaves. No difference was recorded in concentration of total phenolics between leaf forms, but more protein was precipitated (an estimate of tannin activity) in extracts from juvenile leaves. Cyanogenic glycosides were absent from mature leaves, but present in young leaves of both leaf forms in E. polyanthemos. No significant difference in concentration of any terpene was recorded between adult and juvenile leaves in E. nitens and E. regnans. Specific leaf area was lower in adult leaves, and fibre concentration was higher in adult leaves of some species, suggesting that resources in the adult leaf may be less accessible to a herbivore. However, there was no difference in leaf toughness between leaf forms, even though toughness per unit leaf thickness was higher in juvenile leaves. Hence, no major trends in resource concentration were apparent between the leaf forms, and of the defences investigated, only tannin activity varied significantly between the leaf forms.

Protective Effect of an Ectomycorrhizal Fungus against the Root Pathogen Myceliumradicisatrovirens

1971 ◽  
Vol 1 (4) ◽  
pp. 246-251 ◽  
Author(s):  
Claude Richard ◽  
J.-André Fortin ◽  
Alain Fortin
Keyword(s):  
Protective Effect ◽  
Ectomycorrhizal Fungus ◽  
Phytopathogenic Fungus ◽  
Root Pathogen ◽  
Disease Symptoms

The ectomycorrhizal fungus Suillusgranulatus prevented the phytopathogenic fungus Myceliumradicisatrovirens from adversely affecting the growth of aseptically grown seedlings of Piceamariana. Disease symptoms caused by M. radicisatrovirens are summarized for aseptically grown pine and spruce seedlings.

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