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

Abstract

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.

Ribosomal DNA analyses reveal greater sequence variation in Polymyxa species than previously thought and indicate the possibility of new ribotype‐host‐virus associations

“…tropicalis ). This ribotype had previously only been seen in tropical locations (India and West Africa), associated with crops such as sorghum, pearl millet and maize, although they have been reported to show very limited infection of barley and wheat (Legrève et al ., 2000; 2005; Dieryck et al ., ). Our work shows that these isolates are not restricted to tropical regions and have a wider distribution than previously thought.…”

“…colombiana). Ribotype IV transmits Peanut clump virus and is found in barley, maize, sorghum, pearl millet and wheat in the Indian subcontinent and West Africa (Dieryck et al, 2011). For some years, the only report of ribotype V was from rice in Colombia (Morales et al, 1999).…”

Polymyxa graminis Isolates from Australia: Identification in Wheat Roots and Soil, Molecular Characterization, and Wide Genetic Diversity

“…Each phase is initiated by the attachment o f zoo spores and penetration of epidermal or root hair cells. IPCV and PCV sometimes cause damaging diseases of wheat growing under subtropical conditions (11,31). These viruses oc cur in parts of Europe.…”

Occurrence ofPolymyxa graminisRibotypes in Germany and Their Association with Different Host Plants and Viruses

“…Dieryck et al (2011) have suggested the existence of a co-evolution mechanism between PCV, vector and host plant. This could lead to local adaptation, which could be a reason for differences in aggressiveness.…”

“…tepida -on wheat and other cereals (Ward et al 2005;Vaianopoulos et al 2007). Dieryck et al (2011) have shown that the PCV transmission efficiency depends on the P. graminis special forms. P. graminis f. sp.…”