Author
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Thomas, Peter |
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Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/26/2004 Publication Date: 7/1/2004 Citation: Thomas, P.E. 2004. Black and hairy nightshade, the first weedy hosts of potato virus a (pva; genus:potyvirus; family:potyviridae) in the usa. Plant Disease. 88:905. Interpretive Summary: Potato virus A (PVA) occurs wherever potatoes are grown and may reduce tuber yields up to 40%. Its prevalence has increased markedly in potato growing regions of the nation. Until now, the virus had only two known natural hosts, potato itself and tree tomato Solanum betaceae, a host confined to tropical and subtropical regions. Thus, we believed that survival and spread of PVA in temperate climates depended entirely on the potato crop. Now we know that two weed species, perhaps the most important and difficult to control weeds of potato crops, are excellent hosts of PVA. Strategies to control the virus must take this new knowledge into account. Technical Abstract: We have isolated PVA from Black Nightshade (Solanum nigrum L.) and Hairy nightshade (S. sarrachoides Sendt.) weeds growing in PVA-infected potato fields and expressing mild mosaic symptoms. We have fulfilled the requirements of Kochs postulates to prove that the virus isolated is the cause of the disease observed in the weeds and that it is PVA. This establishes that two predominate and difficult to control weeds of potato crops are the first known natural weedy hosts of PVA in temperate climates. |
