Temporal spore dispersal patterns of grapevine trunk pathogens in South Africa

The airborne inoculum of Fusarium circinatum, the fungal pathogen causing Pine Pitch Canker (PPC), is one of the main means of spread of the disease in forest stands and forest nurseries. Since this world-wide known pathogen was introduced in Europe, its biology in this newly infected area still remains scarcely known. To shed more light on this topic, we set an experiment on a naturally PPC infected forest of Monterey pine in Galicia (NW Spain) with the following two goals: (i) to describe the seasonal spore dispersal pattern during one year of regular sampling and (ii) to assess the spatial spore dispersal pattern around the infested plot. Portable rotating arm spore traps were used and complemented with meteorological measurements. The abundance of F. circinatum spores in the samples was evaluated by quantitative PCR (qPCR) with hydrolysis probe. The results showed almost permanent occurrence of the air inoculum throughout the whole year, being detected in 27 of the 30 samplings. No clear temporal trends were observed, but higher air inoculum was favoured by previous lower air temperatures and lower leaf wetness. Conversely, neither rainfall nor air humidity seemed to have any significant importance. The spatial spread of the inoculum was noted to be successful up to a distance of 1000 m in the wind direction, even with winds of just 5 m s-1. Our study shows that rotating arm spore traps combined with qPCR may be an efficient tool for F. circinatum detection.

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Molecular Methods to Detect and Quantify Botryosphaeriaceae Inocula Associated With Grapevine Dieback in Australia

Plant Disease ◽

10.1094/pdis-11-17-1854-re ◽

2018 ◽

Vol 102 (8) ◽

pp. 1489-1499 ◽

Cited By ~ 11

Author(s):

Regina Billones-Baaijens ◽

José Ramón Úrbez-Torres ◽

Meifang Liu ◽

Matthew Ayres ◽

Mark Sosnowski ◽

...

Keyword(s):

Fungal Species ◽

Molecular Tools ◽

Spore Dispersal ◽

Dispersal Patterns ◽

Spore Trap ◽

Synthetic Dna ◽

Qpcr Method ◽

Botryosphaeria Dieback ◽

Grapevine Dieback ◽

Rain Splash

Botryosphaeria dieback, caused by species of Botryosphaeriaceae, is an important grapevine trunk disease in Australia. Inocula produced by the pathogens are primarily dispersed by rain splash and wind and infect pruning wounds leading to cankers, dieback, and eventually death of vines. The objective of this study was to develop molecular tools to detect and quantify Botryosphaeriaceae inocula from the environment. These tools are essential for investigating spore dispersal patterns of Botryosphaeriaceae pathogens in Australian vineyards. DNA extraction protocols were evaluated and one modified protocol was found suitable for extracting Botryosphaeriaceae DNA from artificially and naturally inoculated Burkard volumetric spore sampler tapes. Multispecies primers and a hydrolysis probe for quantitative PCR (qPCR) were further developed to detect and quantify Botryosphaeriaceae inocula from environmental samples. Specificity tests showed that the multispecies primers were able to amplify the DNA of 10 Botryosphaeriaceae species (58 isolates) found in Australia while none of the 27 nontarget fungal species (90 isolates) tested were amplified. The qPCR assay was suitable for amplifying purified DNA, synthetic DNA fragments (gBlocks), and mixed DNA from spore trap tapes. The qPCR method developed in this study was shown to be rapid and sensitive in detecting Botryosphaeriaceae inocula from the environment using spore traps.

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Spore Dispersal Patterns of Fusarium circinatum on an Infested Monterey Pine Forest in North-Western Spain

Forests ◽

10.3390/f8110432 ◽

2017 ◽

Vol 8 (11) ◽

pp. 432 ◽

Cited By ~ 10

Author(s):

Miloň Dvořák ◽

Patrik Janoš ◽

Leticia Botella ◽

Gabriela Rotková ◽

Rafael Zas

Keyword(s):

Pine Forest ◽

Fusarium Circinatum ◽

Spore Dispersal ◽

Dispersal Patterns ◽

Monterey Pine ◽

Western Spain ◽

North Western

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Meteorological Factors Affecting Airborne Conidia Concentrations and the Latent Period of Podosphaera clandestina on Sweet Cherry

Plant Disease ◽

10.1094/pdis.1998.82.7.741 ◽

1998 ◽

Vol 82 (7) ◽

pp. 741-746 ◽

Cited By ~ 14

Author(s):

Gary G. Grove

Keyword(s):

Latent Period ◽

Meteorological Parameter ◽

Type I ◽

Bud Burst ◽

Spore Dispersal ◽

Dispersal Patterns ◽

Factors Affecting ◽

Random Dispersal ◽

Early Afternoon ◽

Airborne Conidia

Conidia of Podosphaera clandestina were trapped beginning about 1 month after bud burst and continuing through the majority of the fruit development period and beyond. The presence of airborne conidia generally followed a diurnal pattern, with peak concentrations occurring in late morning to early afternoon. The three general spore dispersal patterns described by Sutton and Jones for P. leucotricha were observed: diurnal dispersal with concentrations peaking about midday (type I dispersal); random dispersal in which the spore concentrations were not correlated with any measured meteorological parameter (type II dispersal); and dispersal associated with the onset of rain (type III dispersal). Positive correlations with wind speed and temperature, and negative correlations with relative humidity, were characteristic of days when spore dispersal was diurnal. Consistent correlations with meteorological parameters were not detected on days with random or rain-onset dispersal. The latent period of P. clandestina on cherry foliage was found to be shortest at 20 to 25°C and was influenced by temperature and incubation time.

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Time and Latitude in South Africa

International Astronomical Union Colloquium ◽

10.1017/s0252921100026816 ◽

1972 ◽

Vol 1 ◽

pp. 27-38

Author(s):

J. Hers

Keyword(s):

South Africa ◽

Cape Town ◽

Astronomical Observations ◽

Royal Observatory ◽

The Republic ◽

Astronomical Determination ◽

Limited Accuracy ◽

Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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Indirect Rule in South Africa

10.1017/upo9781580467421 ◽

2009 ◽

Author(s):

J. C. Myers

Keyword(s):

South Africa ◽

Indirect Rule

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Combining Professional Interests and Travel: People to People Citizen Ambassador Program

Perspectives on Global Issues in Communication Sciences and Related Disorders ◽

10.1044/gics1.2.47 ◽

2011 ◽

Vol 1 (2) ◽

pp. 47-54

Author(s):

Alex Johnson ◽

Amanda Hitchins

Keyword(s):

South Africa ◽

Health Education ◽

Communication Disorders ◽

Social Conditions ◽

Speech Language Pathologists ◽

Exchange Program

Abstract This article summarizes a series of trips sponsored by People to People, a professional exchange program. The trips described in this report were led by the first author of this article and include trips to South Africa, Russia, Vietnam and Cambodia, and Israel. Each of these trips included delegations of 25 to 50 speech-language pathologists and audiologists who participated in professional visits to learn of the health, education, and social conditions in each country. Additionally, opportunities to meet with communication disorders professionals, students, and persons with speech, language, or hearing disabilities were included. People to People, partnered with the American Speech-Language-Hearing Association (ASHA), provides a meaningful and interesting way to learn and travel with colleagues.

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