Acquisition and Transmission of Peanut clump virus by Polymyxa graminis on Cereal Species

• Published in: Phytopathology 2011-10, Vol.101 (10), p.1149-1158
• Main Authors: Dieryck, Benjamin, Weyns, Jeannine, Doucet, Diane, Bragard, Claude, Legrève, Anne
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biological Evolution; Burkina Faso; coevolution; Edible Grain - parasitology; Edible Grain - virology; Fundamental and applied biological sciences. Psychology; grains; host plants; Host Specificity; Host-Pathogen Interactions; Niger; pathogenicity; Peanut clump virus; Pennisetum glaucum; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - parasitology; Plant Diseases - virology; Plant Roots - parasitology; Plant Roots - virology; Plant Viruses - isolation & purification; Plant Viruses - physiology; Plant viruses and viroids; Plasmodiophorida - growth & development; Plasmodiophorida - physiology; Plasmodiophorida - virology; Poaceae - parasitology; Poaceae - virology; Polymyxa; Polymyxa graminis; reverse transcriptase polymerase chain reaction; RNA Viruses - isolation & purification; RNA Viruses - physiology; sugarcane; virus transmission; viruses; zoospores
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/PHYTO-12-10-0335

The objective of this study was to investigate the specificity of the interactions between Polymyxa graminis, Peanut clump virus (PCV), and cereals, particularly the acquisition and the transmission of the virus by three P. graminis formae speciales. A new strategy has been developed: it involves using sugarcane as the common host for both the virus and its vector in order to produce the viruliferous zoospores of P. graminis f. sp. subtropicalis, temperata, and tropicalis that were then inoculated on cereal species. This experiment enabled the role of P. graminis f. sp. tropicalis and subtropicalis zoospores in PCV transmission to be demonstrated. The efficiency of this transmission was shown to vary, depending on the P. graminis special forms. Interestingly, the high transmission of the PCV isolate from Burkina Faso by an isolate of P. graminis f. sp. tropicalis from Niger on pearl millet suggests that there is a coevolution mechanism in this pathosystem. The study also provides evidence that the host plant species in which Polymyxa zoospores are produced could affect the infectivity of the vector. Finally, using Polymyxa quantitation by quantitative reverse-transcription polymerase chain reaction and in situ observations of the virus, the study demonstrates the independence of the development of PCV and its vector in the host plants.