Indirect Effect of Floristic Composition on Production of Sporangia by Phytophthora cinnamomi in Jarrah Forest Soils

1985 ◽  
Vol 33 (1) ◽  
pp. 109 ◽  
Author(s):  
DIL Murray ◽  
DD Darling ◽  
LR Mcgann
Keyword(s):  
Direct Effect ◽  
Forest Soils ◽  
Indirect Effect ◽  
Physical Environment ◽  
Phytophthora Cinnamomi ◽  
Floristic Composition ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Per Se ◽  
Zoospore Discharge

Production of sporangia and zoospore discharge by Phytophthora cinnamomi were investigated in jarrah forest soils collected beneath Acacia pulchella, Banksia grandis and Eucalyptus marginata and incubated under conditions which excluded a direct effect of these species on the soil physical environment. Sporangium production was always significantly greater in soils from B. grandis than in soils from A. pulchella; soils from E. marginata gave intermediate results. There was also evidence that discharge of zoospores was suppressed in soils from A. pulchella. Although three isolates of P. cinnamomi differed in their abilities to sporulate per se, they responded similarly to different treatments.

Distribution of Phytophthora cinnamomi in the northern jarrah (Eucalyptus marginata) forest of Western Australia in relation to dieback age and topography

2002 ◽  
Vol 50 (1) ◽  
pp. 107 ◽  
Author(s):  
K. L. McDougall ◽  
G. E. St J. Hardy ◽  
R. J. Hobbs
Keyword(s):  
Spatial Distribution ◽  
Western Australia ◽  
Aerial Photography ◽  
Phytophthora Cinnamomi ◽  
Ex Situ ◽  
Patchy Distribution ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Almost All

The spatial distribution of Phytophthora cinnamomi Rands at seven dieback sites in the jarrah (Eucalyptus marginata Donn. ex Smith) forest of Western Australia was determined by the following two baiting techniques: in situ baiting with live Banksia grandis Willd. seedlings and ex situ baiting of sampled soil and root material. Four areas within each site were sampled, reflecting dieback age and position in the landscape. Approximate dieback ages of 50, 20 and 5 years were determined by aerial photography. The 50-year-old age class was divided into wet valley floor and dry gravelly slope. Phytophthora cinnamomi was recovered most frequently from the 5-year-old (dieback fronts) and wet 50-year-old areas by both baiting techniques. It was recovered from more than twice as many areas and about five times as many samples when in situ B. grandis baits were used compared with ex situ soil and root baiting. Almost all recoveries from in situ baits were made between October and December. From both methods, it appears that P. cinnamomi has a patchy distribution within dieback sites in the northern jarrah forest. It is easily detected only on dieback fronts and wet valley floors. On dry gravelly sites affected 20 years or more ago, P. cinnamomi is rare and may even be absent at some sites. This makes confident detection of the pathogen difficult. In situ baiting at least allows a temporal component to the sampling and will be a useful method of detection in areas where P. cinnamomi is rare or transient.

Rhizosphere Microorganisms From the Jarrah Forest of Western Australia and Their Effects on Vegetative Growth and Sporulation in Phytophthora cinnamomi Rands

1987 ◽  
Vol 35 (5) ◽  
pp. 567 ◽  
Author(s):  
DIL Murray
Keyword(s):  
Vegetative Growth ◽  
Mycelial Growth ◽  
Phytophthora Cinnamomi ◽  
Inhibitory Effect ◽  
The Other ◽  
Microbial Competition ◽  
Eucalyptus Marginata ◽  
Rhizosphere Microflora ◽  
Dual Cultures ◽  
Zoospore Discharge

Soil dilution plate techniques were used to compare the numbers of bacteria, actinomycetes and fungi in the rhizospheres of Acacia pulchella, Banksia grandis and Eucalyptus marginata (jarrah). The most frequently isolated microorganisms and those detected in significantly different numbers in the rhizospheres of the three species were tested for their effects on sporangium production, zoospore discharge, zoospore germination and mycelial growth of the jarrah dieback pathogen Phytophthora cinnamomi. The total population of fungi in rhizosphere soil from B. grandis was much greater than that found in the rhizospheres of the other two species while the convesse was true for bacteria and actinomycetes, of which the largest populations were associated with A. pulchella. Penicillium spinulosum outnum- bered the combined population of other fungi in the Banksia rhizosphere but formed a much smaller proportion of the jarrah and Acacia rhizosphere microfloras, particularly the latter. P. spinulosum had no effect on mycelial growth or zoospore discharge in P. cinnamomi; it had some ability to stimulete sporangium production and, although it partly suppressed spore germination, the inhibitory effect was less pronounced than that noted for most other microorganisms. In contrast, microorganisms which strongly inhibited mycelial growth, zoospore discharge and germination represented a greater proportion of the Acacia rhizosphere microflora compared with the other microfloras, especially that of B. grandis. While some actinornycetes and fungi produced antibiotics that inhibited vegetative growth of P. cinnamomi in dual cultures, mycelial inhibition was often attributable to nutrient depletion of agar media by the test microorganisms. Similarly, nutrient deprivation resulting from microbial competition for substrates was also considered to be the stimulus for sporangium production in liquid media. The results are discussed in relation to previously reported suppression of P. cinnamomi in forest soils beneath stands of A. pulchella and the associated implications of this for biological control of jarrah dieback.

Vegetation of Phytophthora cinnamomi-infested and adjoining uninfested sites in the northern jarrah (Eucalyptus marginata) forest of Western Australia

2002 ◽  
Vol 50 (3) ◽  
pp. 277 ◽  
Author(s):  
K. L. McDougall ◽  
R. J. Hobbs ◽  
G. E. St Hardy
Keyword(s):  
Western Australia ◽  
Phytophthora Cinnamomi ◽  
Annual Plants ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Number Of Species ◽  
Trees And Shrubs ◽  
Lower Cover

The vegetation of seven sites in the northern jarrah forest of Western Australia infested with Phytophthora cinnamomi was recorded and compared with adjoining vegetation. The number of species per quadrat was found to be the same in vegetation affected by P. cinnamomi as in healthy vegetation, although there were more species overall in affected vegetation. Vegetation of uninfested sites had a higher cover and more species per quadrat of trees and shrubs and lower cover and fewer species per quadrat of annual plants than vegetation of infested sites. Although many species that are known to be highly susceptible to infection by P. cinnamomi were rare at infested sites, only two (Banksia grandis and Tetratheca hirsuta) were absent from all of the 50-year-old infested parts of sites. Several species that are known to be highly susceptible to infection by P. cinnamomi were as common at infested as at healthy sites. The presence of such species at infested sites and the capacity of P. cinnamomi to infect species it does not kill suggest that this pathogen will persist and continue to influence future vegetation in the jarrah forest.

Distribution of understorey species in forest affected by Phytophthora cinnamomi in south-western Western Australia

2005 ◽  
Vol 53 (8) ◽  
pp. 813 ◽  
Author(s):  
K. L. McDougall ◽  
R. J. Hobbs ◽  
G. E. St J. Hardy
Keyword(s):  
Western Australia ◽  
Phytophthora Cinnamomi ◽  
Spatial Relationship ◽  
Common Species ◽  
Random Sets ◽  
Tree Cover ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Resistant Species ◽  
Study Sites

The introduced soil-borne pathogen Phytophthora cinnamomi Rands infects and kills a large number of species in the jarrah (Eucalyptus marginata Donn. ex Smith) forest of Western Australia, causing great floristic and structural change. Many of the floristic changes can be explained simply by the known susceptibility of species to infection. Some common species, however, are rarely found at infested sites but are thought to be resistant to infection. It has been postulated that such species may be affected by the change in habitat caused by the death of trees, and not by P. cinnamomi directly. If this were the case, such species should cluster around surviving trees at infested sites. The occurrence of a susceptible species in the vicinity of trees surviving at infested sites has also been reported. To investigate the spatial relationship between trees and understorey species, the positions of trees and selected perennial understorey species were mapped at two sites in jarrah forest long-affected by P. cinnamomi. Random sets of plants and trees were generated and used in simulations to test whether understorey species grew closer to trees than expected. Many understorey species, both resistant and susceptible to infection by P. cinnamomi, were found to grow closer than expected to trees currently growing at the sites and closer to the trees that would have been present at the time of infestation. This suggests that not only do these trees enable some resistant species to persist at infested sites but that they also offer protection to some susceptible species against damage by P. cinnamomi. The proximity of many understorey species to trees that are likely to have appeared at the study sites since the first infestation indicates that the maintenance and enhancement of tree cover at infested sites in the jarrah forest may limit the damage caused by P. cinnamomi and assist in the protection of biodiversity.

Faktor-Faktor yang Mempengaruhi Minat Beli Produk Makanan Olahan Halal pada Konsumen

2018 ◽  
Vol 8 (3) ◽  
pp. 250
Author(s):  
Saniatun Nurhasah ◽  
Jono M Munandar ◽  
Muhammad Syamsun
Keyword(s):  
Food Safety ◽  
Direct Effect ◽  
Indirect Effect ◽  
Purchase Intention ◽  
Brand Image ◽  
Perceived Value ◽  
Perceived Quality ◽  
Market Potential ◽  
Purchasing Intention ◽  
Positive Direct

<p><em>ABSTRACT</em></p><p><em>Indonesia is one of the largest Moslem population countries in the world. It leads to the increasing of halal product demand in Indonesia. The awareness to consume halal product becomes a large market potential for producers to produce their halal products. Nowadays, halal is not only purely about religion matter, but also about business and trade. The objective of this study is to investigate the factors affecting customers on purchasing halal buying interest on processed food. We use a purposive sampling method with 109 respondents who are customers of the supermarkets and minimarkets in Bogor City/District, Indonesia. While data analysis is done by SEM-PLS method, this study uses brand image, perceived quality, perceived value, halal certification, health reason, halal awareness, and halal marketing as the factors which are affecting the halal purchase intention of the customers. The result showed that health reason, halal awareness, and perceived value have a significant and positive direct effect on purchasing intention. Halal marketing also shows a significant and positive effect on purchasing intention. While halal marketing shows a negative and significant effect on purchasing intention. The food safety, halal certification, brand image, and perceived quality show the same effect which has no direct effect on purchasing intention. Furthermore, food safety has an indirect effect on purchasing intention through health reason. Halal certification has an indirect effect on minat beli through brand image variable. Meanwhile, brand image and perceived quality have an indirect effect through perceived value variable on purchasing intention.</em></p><p><em><br /></em></p><p>ABSTRAK</p><p>Indonesia adalah salah satu negara dengan populasi Muslim terbesar di dunia. Hal ini menyebabkan meningkatnya permintaan produk halal di Indonesia. Kesadaran untuk mengkonsumsi produk halal menjadi potensi pasar yang besar bagi produsen untuk memproduksi produk halal mereka. Saat ini, halal tidak hanya murni soal agama, tapi juga soal bisnis dan perdagangan. Tujuan dari penelitian ini adalah untuk mengetahui faktor-faktor yang mempengaruhi minat pelanggan dalam membeli pada makanan olahan halal. Kami menggunakan metode voluntery sampling dengan 109 responden yang merupakan pelanggan supermarket dan minimarket di Kota/Kabupaten Bogor, Indonesia. Sedangkan analisis data dilakukan dengan metode SEM-PLS. Penelitian ini menggunakan citra merek, persepsi kualitas, persepsi nilai, sertifikasi halal, kesehatan, kesadaran halal, dan Pemasaran halal sebagai faktor yang mempengaruhi niat pembelian halal pelanggan. Hasil penelitian menunjukkan bahwa kesadaran halal, alasan kesehatan, dan persepsi nilai berpengaruh positif dan signifikan terhadap niat beli. Pemasaran halal juga menunjukkan efek positif dan signifikan terhadap niat beli. Sedangkan pemasaran halal menunjukkan efek negatif dan signifikan terhadap niat beli. Keamanan pangan, sertifikasi halal, citra merek, dan kualitas yang dirasakan menunjukkan efek yang sama yang tidak berpengaruh langsung pada niat beli. Selanjutnya, keamanan pangan berpengaruh tidak langsung terhadap niat beli melalui alasan kesehatan. Sertifikasi halal memiliki efek tidak langsung terhadap niat beli melalui variabel citra merek. Sedangkan citra merek dan persepsi kualitasmemiliki pengaruh tidak langsung melalui persepsi nilai variable terhadap niat beli.</p>

Infection by Phytophthora cinnamomi Rands of Roots of Eucalyptus calophylla R.Br. and Eucalyptus marginata Donn. ex Sm

1977 ◽  
Vol 25 (5) ◽  
pp. 483 ◽  
Author(s):  
N Malajczuk ◽  
AJ Mccomb ◽  
CA Parker
Keyword(s):  
Phytophthora Cinnamomi ◽  
Light And Electron Microscopy ◽  
Inhibitory Effect ◽  
Lateritic Soil ◽  
Root Damage ◽  
Mature Trees ◽  
Cortical Cells ◽  
Eucalyptus Marginata ◽  
Seedling Roots ◽  
Loam Soil

On lateritic podzolic soils in Western Australia Eucalyptus calophylla is resistant to Phytophthora cinnamomi whereas Eucalyptus marginata is susceptible and eventually killed by the pathogen. On loam soils both eucalypts are resistant. Possible mechanisms for resistance of E. calophylla in lateritic soil and the inhibitory action of loam soils were investigated. Aseptically raised eucalypt seedlings succumbed to infection in liquid culture tubes. The mechanism of infection was compared by light and electron microscopy which showed similar fungal invasion and penetration into roots of both eucalypt species. Vegetative hyphae initially penetrated intercellularly and proliferated rapidly within cortical and stelar tissue. Intracellular invasion of these tissues occurred 48hr after initial infection through dissolution of the host cell wall. Chlamydospores were formed within a number of cortical cells. Unsuberized roots of mature trees produced aseptically showed reactions to invasion similar to those of the eucalypt seedling roots. Suberized roots were not invaded. The addition of small quantities of lateritic soil to sterile sand so as to introduce soil micro-organisms without altering the chemical and physical status of the sand, and subsequent inoculation of the sand with P.cinnamomi, resulted in a reduction of root damage on both eucalypts when compared with seedlings raised in sterile sand. Roots of E.calophylla were less severely damaged than those of E.marginata. The addition of small quantities of loam soil significantly reduced root damage in seedlings of both species. These results parallel both pot experiments and field observations, and suggest that microorganisms of the rhizosphere may be an important factor in the resistance of E.calophylla to infection, and in the inhibitory effect of loam soil on P.cinnamomi.

Tree Species Preferences of Foraging Birds in Jarrah Forest in Western Australia.

1985 ◽  
Vol 12 (3) ◽  
pp. 461 ◽  
Author(s):  
I Abbott ◽  
PV Heurck
Keyword(s):  
Western Australia ◽  
Tree Species ◽  
Bird Species ◽  
Selective Logging ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Silvicultural Treatments ◽  
Species Preferences

A study of foraging by 10 bird species suggests that selective logging of large Eucalyptus marginata will only have affected Melithreptus lunatus, but that proposed silvicultural treatments, including removal of Banksia grandis, may affect several other bird species.

Moral Disengagement About Cyberbullying and Parental Monitoring: Effects on Traditional Bullying and Victimization via Cyberbullying Involvement

2016 ◽  
Vol 38 (3) ◽  
pp. 303-326 ◽  
Author(s):  
Diana J. Meter ◽  
Sheri Bauman
Keyword(s):  
Direct Effect ◽  
Indirect Effect ◽  
Indirect Effects ◽  
Parental Monitoring ◽  
Moral Disengagement ◽  
Traditional Bullying ◽  
Traditional Victimization ◽  
And Gender

The indirect effects of moral disengagement about cyberbullying and parental monitoring on traditional victimization and bullying via cyberbullying involvement were examined in a diverse sample of 800 youth in Grades 3 to 8. After controlling for grade and gender, moral disengagement about cyberbullying and parental monitoring had an indirect effect on traditional victimization and bullying through cyberbullying involvement. Moral disengagement about cyberbullying and parental monitoring had a direct effect on traditional bullying. Results suggest that moral disengagement about cyberbullying and parental monitoring affect cyberbullying involvement and additionally impact experiences beyond the cyber context.

THE EFFECT OF EXOGENOUS HORMONES ON AGGRESSIVE AND DEFENSIVE BEHAVIOUR IN THE RING DOVE (STREPTOPELIA RISORIA)

1966 ◽  
Vol 36 (1) ◽  
pp. 35-51 ◽  
Author(s):  
D. M. VOWLES ◽  
D. HARWOOD
Keyword(s):  
Direct Effect ◽  
Indirect Effect ◽  
Aggressive Behaviour ◽  
Breeding Cycle ◽  
Defensive Behaviour ◽  
Hormonal Effects ◽  
Streptopelia Risoria ◽  
Ring Dove ◽  
Second Peak ◽  
Model Predator

SUMMARY The aggressive and defensive behaviour of the ring dove was studied in response to a model predator and to another member of the same species. During a single breeding cycle defensive behaviour increased rapidly just before laying, reached a second peak at the time of hatching, and declined as the squabs became independent. Cocks showed aggressive behaviour to other doves throughout the cycle, but this response reached a peak soon after laying, and declined at the time of hatching. The effects of seven daily injections of oestrogen, progesterone, progesterone plus oestrogen, testosterone, and prolactin were studied. In both sexes prolactin and progesterone (with and without oestrogen) increased defensive behaviour towards a predator; in hens these hormones also increased defensive behaviour towards other birds. In cocks, however, prolactin had no effect on the response to other doves; progesterone (with and without oestrogen) increased aggressiveness, and oestrogen increased nest-cooing. Single injections of the same hormones produced similar effects, with the exception that testosterone and oestrogen in hens caused a temporary (1–5 hr.) increase in defensive behaviour. The latency of most hormonal effects was 30 min. to 2 hr., although the injections were intramuscular. This suggests a direct effect on central nervous mechanisms. Progesterone had a latency of 12–18 hr., suggesting an indirect effect.

Optimising smoke treatments for jarrah (Eucalyptus marginata) forest rehabilitation

2006 ◽  
Vol 54 (6) ◽  
pp. 571 ◽  
Author(s):  
Melanie A. Norman ◽  
Julie A. Plummer ◽  
John M. Koch ◽  
Greg R. Mullins
Keyword(s):  
Rehabilitation Program ◽  
Forest Species ◽  
Dormancy Breaking ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Bauxite Mining ◽  
Application Methods ◽  
Forest Rehabilitation ◽  
Irreversible Nature ◽  
Smoke Water

Alcoa is undertaking rehabilitation in the jarrah (Eucalyptus marginata D.Don ex Sm.) forest of Western Australia, following bauxite mining. One of the methods used in the rehabilitation program is broadcasting seeds; however, about two-thirds of species require seed-dormancy-breaking treatments. Smoke overcomes dormancy and enhances the germination of many jarrah forest species. Smoke-application methods were investigated to find the best seed treatment for 64 jarrah forest species. The optimum duration of seed imbibition in aqueous smoke and dilution of the aqueous smoke product were also investigated. The method of smoke application was important. Smoke water enhanced the germination of 12% of species, whereas aerosol smoke enhanced the germination of 6% of species. Both Grevillea pilulifera (Lindl.) Druce and Velleia trinervis Labill. had germination enhanced by both smoke-application methods. Aerosol smoke inhibited the germination of Clematis pubescens Endl. and Hypocalymma angustifolium (Endl.) Schauer. A total of 78% of species did not exhibit significantly enhanced germination when smoke treated, including the two species inhibited by smoke treatment. Germination was equivalent following 1- and 12-h imbibition in the aqueous smoke extract. Dilutions of the aqueous extract Regen 2000 Smokemaster from 1 to 3% were optimal for the germination of Marianthus bicolor (Putt.) F.Muell and Stylidium amoenum R.Br., even after subsequent washing with water, demonstrating the irreversible nature of smoke treatments. For species that did not exhibit smoke-enhanced germination, other dormancy-breaking treatments may be required before a response to smoke is elicited. These results have application to a wide variety of natural managed lands, disturbed and designed landscapes.

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