primary inoculum
Recently Published Documents


TOTAL DOCUMENTS

85
(FIVE YEARS 4)

H-INDEX

20
(FIVE YEARS 1)

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2288
Author(s):  
Tao Ji ◽  
Irene Salotti ◽  
Chaoyang Dong ◽  
Ming Li ◽  
Vittorio Rossi

Ripe rot caused by Colletotrichum spp. is a serious threat in many vineyards, and its control relies mainly on the repeated use of fungicides. A mechanistic, dynamic model for the prediction of grape ripe rot epidemics was developed by using information and data from a systematic literature review. The model accounts for i) the production and maturation of the primary inoculum; ii) the infection caused by the primary inoculum; iii) the production of a secondary inoculum; and iv) the infection caused by the secondary inoculum. The model was validated in 19 epidemics (vineyard × year combinations) between 1980 and 2014 in China, Japan, and the USA. The observed disease incidence was correlated with the number of infection events predicted by the model and their severity (ρ = 0.878 and 0.533, respectively, n=37, P≤ 0.001). The model also accurately predicted the disease severity progress during the season, with a concordance correlation coefficient of 0.975 between the observed and predicted data. Overall, the model provided an accurate description of the grape ripe rot system, as well as reliable predictions of infection events and of disease progress during the season. The model increases our understanding of ripe rot epidemics in vineyards and will help guide disease control. By using the model, growers can schedule fungicides based on the risk of infection rather than on a seasonal spray calendar.


Plant Disease ◽  
2020 ◽  
Vol 104 (1) ◽  
pp. 255-259 ◽  
Author(s):  
Yanli Tian ◽  
Yuqiang Zhao ◽  
Jiaju Zhou ◽  
Ting Sun ◽  
Xue Luo ◽  
...  

Acidovorax citrulli is the causal agent of bacterial fruit blotch (BFB), a serious threat to cucurbit fruit and seed production worldwide. In recent years, the BFB has spread to many areas of China, mainly via the inadvertent distribution of contaminated commercial seeds. To assess the prevalence of seedborne A. citrulli in commercial watermelon and other cucurbitaceous seedlots in China, a 9-year survey was conducted between 2010 and 2018. A total of 4,839 seedlots of watermelon and other cucurbitaceous species were collected from 13 major seed production areas of China and tested by a semiselective media-based colony PCR technique for A. citrulli. Overall, A. citrulli was detected in 18.00% (871/4,839) of all cucurbitaceous seedlots. The bacterium was detected in 21.59% (38/176), 19.19% (33/172), 23.44% (214/913), 40.76% (247/606), 13.28% (85/640), 15.40% (95/617), 13.25% (73/551), 8.03% (48/598), and 6.71% (38/566) of all commercial seedlots tested from the 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, and 2018 growing seasons, respectively. Additionally, the prevalence of A. citrulli in cucurbit seedlots was determined for different seed production areas. The prevalence of A. citrulli in cucurbitaceous seedlots produced in Xinjiang, Gansu, Ningxia, Inner Mongolia, and 9 other provinces was 18.76% (582/3103), 26.34% (103/391), 21.47% (82/382), 11.11% (14/126), and 10.75% (90/837), respectively. This is the first survey for A. citrulli in commercial cucurbit seeds in China, and the relatively high prevalence suggests that commercial seeds represent a substantial source of primary inoculum that can threaten cucurbit seed and fruit production in China.


Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3209-3217 ◽  
Author(s):  
Natasha Akemi Hamada ◽  
Rafaele Regina Moreira ◽  
Cristiano Nunes Nesi ◽  
Louise Larissa May De Mio

Glomerella leaf spot (GLS) of apple is caused by three different Colletotrichum species complexes. This study evaluated the dispersal of Colletotrichum spores related to GLS temporal progress and defoliation. Spores were monitored by air and water runoff in different plant heights, and the temporal progress of GLS and defoliation were assessed. Spores of the pathogen were first cached in the lower part of the tree closer to the ground, confirming the importance of dead leaves on the ground as main source of primary inoculum. In plots with high primary inoculum, the disease increases exponentially during favorable weather conditions. The highest initial inoculum was found in the lower part of the tree, but the highest rate of the disease progress in the upper.


PLoS ONE ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. e0210871 ◽  
Author(s):  
Naama Levitzky ◽  
Elisheva Smith ◽  
Oded Lachman ◽  
Neta Luria ◽  
Yaniv Mizrahi ◽  
...  

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 102 ◽  
Author(s):  
Ann Hajek ◽  
Donald Steinkraus ◽  
Louela Castrillo

Many of the almost 300 species of arthropod-pathogenic fungi in the Entomophthoromycotina (Zoopagomycota) are known for being quite host-specific and are able to cause epizootics. Most species produce two main types of spores, conidia and resting spores. Here, we present a review of the epizootiology of species of Entomophthoromycotina, focusing on their resting spores, and how this stage leads to horizontal transmission and persistence. Cadavers in which resting spores are produced can often be found in different locations than cadavers of the same host producing conidia. Resting spores generally are dormant directly after production and require specific conditions for germination. Fungal reproduction resulting from infections initiated by Entomophaga maimaiga resting spores can differ from reproduction resulting from conidial infections, although we do not know how commonly this occurs. Reservoirs of resting spores can germinate for variable lengths of time, including up to several months, providing primary infections to initiate secondary cycling based on conidial infections, and not all resting spores germinate every year. Molecular methods have been developed to improve environmental quantification of resting spores, which can exist at high titers after epizootics. Ecological studies of biological communities have demonstrated that this source of these spores providing primary inoculum in the environment can decrease not only because of germination, but also because of the activity of mycopathogens.


2018 ◽  
pp. 275-280
Author(s):  
A. Boix-Ruiz ◽  
M.A. Gómez-Tenorio ◽  
C. Ruiz-Olmos ◽  
J.I. Marín-Guirao ◽  
F. Toresano-Sánchez ◽  
...  

Plant Disease ◽  
2018 ◽  
Vol 102 (4) ◽  
pp. 782-789 ◽  
Author(s):  
Dalia Aiello ◽  
Alessandro Vitale ◽  
Rafael F. Alfenas ◽  
Acelino C. Alfenas ◽  
Gabriella Cirvilleri ◽  
...  

Infested soil is the primary inoculum source for Calonectria spp. for initiating disease in ornamental and forestry crops. The effects of dazomet and metam-sodium on survival of microsclerotia of 28 isolates belonging to 19 Calonectria spp. were evaluated in this study under nursery conditions. Two experiments with exotic Calonectria spp. in plastic containers in a greenhouse and three trials with endemic species in field plots were performed during different seasons. The containers and plots were artificially infested with Calonectria microsclerotia differentiated on carnation leaf tissues. Basamid (dazomet) was applied at 100, 160, 200, 400, and 500 kg/ha, while Divapan (metam-sodium) was applied at 250, 350, 400, 700, and 1,000 liters/ha in both the containers and plots. The fumigants were applied under virtually and totally impermeable films. Fungal survival was evaluated after 21 days using leaf tissues collected from treated soil and plated on potato dextrose agar, and the ability of microsclerotia to cause infection was tested on red clover. The survival of Calonectria inocula and microsclerotia decreased with increasing fumigant rates. In the greenhouse trials, where Basamid was applied at 200, 400, and 500 kg/ha and Divapan at 400, 700, and 1,000 liters/ha, no viable microsclerotia were recovered for 14 exotic Calonectria spp., whereas viable inocula of Calonectria hongkongensis, C. naviculata, and C. sulawesiensis were retrieved from the fumigated plots. Low rates of Basamid (100 and 160 kg/ha) and Divapan (250 and 350 liters/ha) were less effective at reducing Calonectria viability and, for these treatments, the rate of microsclerotia survival was highly variable among the different isolates and species. Furthermore, totally impermeable film significantly enhanced fumigant performance. Relative to endemic Calonectria spp., all of the treatments killed microsclerotia of C. polizzii and C. pauciramosa independent from fumigant, rate, and film. This research demonstrated the possibility of reducing the application rates by up to 160 kg/ha for Basamid and 400 liters/ha for Divapan under low-permeability films (virtually impermeable film or totally impermeable film) for eradicating or reducing the primary inoculum of Calonectria spp. in soil.


2018 ◽  
Vol 19 (2) ◽  
pp. 129-130
Author(s):  
Shunwen Lu ◽  
Michael C. Edwards

Fusarium graminearum, the primary pathogen of Fusarium head blight (FHB), undergoes both asexual and sexual stages, and the ascospore is an important primary inoculum of FHB. Induction of the sexual stage under laboratory conditions is important for the study of FHB. Here we report a simple culture method that uses potato dextrose agar plates. This method works as well as the traditional procedure, which depends on carrot extracts and involves multiple steps in preparation.


2017 ◽  
Vol 67 (3) ◽  
pp. 610-618 ◽  
Author(s):  
H. Raveloson ◽  
I. Ratsimiala Ramonta ◽  
D. Tharreau ◽  
M. Sester

Sign in / Sign up

Export Citation Format

Share Document