Specific Polymerase Chain Reaction-Based Assay for the Identification of the Arbuscular Mycorrhizal Fungus Glomus intraradices

2008 ◽  
Vol 8 (3) ◽  
pp. 563-569 ◽  
Author(s):  
J.F. Gomez-Leyv ◽  
J. Lara-Reyna ◽  
L.V. Hernandez- ◽  
J.P. Martinez-S
2003 ◽  
Vol 93 (2) ◽  
pp. 229-235 ◽  
Author(s):  
M. Filion ◽  
M. St-Arnaud ◽  
S. H. Jabaji-Hare

The capacity of the arbuscular mycorrhizal fungus Glomus intraradices in reducing the presence of Fusarium solani f. sp. phaseoli in bean plants and the surrounding mycorrhizosphere soil was evaluated in a compartmentalized experimental system. Quantification of the pathogen and the symbiont in plant tissues, the soil regions of the mycorrhizosphere (rhizosphere and mycosphere), and the bulk soil was accomplished using specific polymerase chain reaction (PCR) primers in real-time PCR assays, culture-dependant methods, and microscopic determination techniques. Nonmycorrhizal bean plants infected with the pathogen had distinctive Fusarium root rot symptoms, while infected plants previously colonized by G. intraradices remained healthy. The amount of F. solani f. sp. phaseoli genomic DNA was significantly reduced in mycorrhizal bean plants and in each mycorrhizosphere soil compartment. The presence of G. intraradices in the mycorrhizosphere was not significantly modified, although the mycorrhizal colonization of roots was slightly increased in the presence of the pathogen. The results suggest that the reduced presence of Fusarium as well as root rot symptoms are caused by biotic and/or abiotic modifications of the mycorrhizosphere as a result of colonization with G. intraradices.


2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.


Plant Disease ◽  
2002 ◽  
Vol 86 (11) ◽  
pp. 1237-1239 ◽  
Author(s):  
R. H. Brlansky ◽  
V. D. Damsteegt ◽  
J. S. Hartung

Citrus variegated chlorosis (CVC) is an economically important, destructive disease in Brazil and is caused by the bacterium Xylella fastidiosa Wells. The bacterium has been found to be transmitted in Brazil by sharpshooter leafhoppers (Cicadellidae). Sharpshooters are present in most citrus growing areas of the United States. The sharpshooter leafhopper, Oncometopia nigricans Walker, frequently is found feeding on citrus in Florida. This sharpshooter transmits the X. fastidiosa strains that cause Pierce's disease of grape and ragweed stunt. Research was initiated to determine if O. nigricans was capable of vectoring the X. fastidiosa that causes CVC. In 59 different transmission tests, using 1 to 57 insects per test, transmission of the bacterium was observed 12 times (20.3%). Symptom development in the greenhouse was not a reliable indicator of transmission. Transmission was verified by specific polymerase chain reaction-based assays. Individual insects were able to transmit the bacterium. This information on sharpshooter transmission of CVC is needed to assess the threat posed by the CVC disease to the citrus industries in the United States.


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