Panicum mosaic virus

Panicum mosaic virus
Virus classification
Group: Group IV ((+)ssRNA)
Family: Tombusviridae[1]
Genus: Panicovirus[1]
Species: Panicum mosaic virus

Panicum mosaic virus (PMV) is a pathogenic plant virus noted for causing the grass disease St. Augustine Decline. It is a positive-sense ssRNA virus and the type species of the genus Panicovirus, readily spread by humans through tools such as lawn mower blades, but not known to be spread via biological vectors such as insects. PMV was identified in 1953, and is known to infect switchgrass, centipedegrass and St. Augustine Grass.

Contents

History

PMV was first observed in Kansas in 1953. It was originally noted to infect switchgrass (Panicum virgatum), and was observed infecting St. Augustine Grass (Stenotaphrum secundatum) in Texas in 1966. The strain specific to St. Augustine Grass has since been observed in Arkansas, Louisiana, Mississippi and South Carolina in the United States, as well as in Mexico. Other strains have been identified infecting centipedegrass (Eremochloa ophiuroides).[1] Foxtail millet (Setaria italica), white proso millet (Panicum miliaceum) and pearl millet (Pennisetum glaucum) have also been used to propagate PMV and panicum mosaic satellite virus (SPMV), and mechanical transmission can occur to maize and some cultivars of common wheat (Triticum aestivum).[2]

Classification

Further information: Tombusviridae

Panicum mosaic virus is the type species of the genus Panicovirus, a member of the plant virus family Tombusviridae.[1] Members of Tombusviridae are transmitted as positive sense single-stranded non-enveloped RNA viruses, with an icosohedral capsid.[3] PMV itself has a genome of 4,326 nucleotides, encapsulated into 30-nm particles by a capsid protein of 26 kDa.[1] PMV was placed in the genus Panicovirus because of its limited monocot host range and lack of an additional 5'-ORF. PMV is serologically related to Molina streak virus and Maize mild mottle virus.[2]

St. Augustine Decline

St. Augustine Decline (SAD) is a viral disease of St. Augustine Grass (Stenotaphrum secundatum), and is the only economically important viral disease in turf management. Research into SAD has implicated PMV, though panicum mosaic satellite virus plays an unknown role in the disease.[1] In SAD, grass blades taken on a mottled, chlorotic appearance, and the disease can spread across large sections of turf.[4] Early SAD may be confused with iron chlorosis, however the latter is characterized by either uniform yellowing or characteristic yellow striping parallel to the mid-vein of the leaf.[5]

There is no cure for SAD, and the most common solution is to replace diseased areas with disease resistant cultivars of St. Augustine Grass, such as Floralawn, Floratam, Raleigh and Seville.[4][5] Resistant grass will crowd out diseased grass over a period of one or more years. Transmission is believed to occur by mechanical means, such as lawn mower blades.[1][5]

References

  1. ^ a b c d e f g Cabrera, Over; Karen-Beth G. Scholthof (October 1999). "The complex viral etiology of St. Augustine decline" (PDF). Plant Disease 83 (10): 902–904. doi:10.1094/PDIS.1999.83.10.902. http://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS.1999.83.10.902. 
  2. ^ a b Lapierre, Hervé; Pierre A. Signoret (2004-10-05). Viruses and virus diseases of Poaceae (Gramineae). Inra. p. 798. ISBN 2738010881. 
  3. ^ ICTVdB - The Universal Virus Database, version 3 00.074. Tombusviridae
  4. ^ a b Christians, Nick (2004). "Fertilization". Fundamentals of Turfgrass Management (2 ed.). John Wiley & Sons. pp. 260, 266. ISBN 0471454788. 
  5. ^ a b c Duble, Richard L. "St. Augustine Decline". Texas Cooperative Extension. http://aggie-horticulture.tamu.edu/archives/parsons/turf/publications/Staugdecline.html. Retrieved 8 August 2010.