EVALUATING THE THREAT POSED BY FUNGI ON THE APHIS LIST OF REGULATED PLANT PESTS

Authors: Rossman, Amy; BRITTON, KERRY - USDA-FOREST SVC,WASH,DC; Luster, Douglas - Doug; PALM, MARY - USDA-APHIS-BELTSVILLE,MD; ROYER, MATT - USDA-APHIS-BELTSVILLE,MD; SHERALD, JIM - DUDA-DOI-NPS

Submitted to: Plant Health Progress
Publication Type: Review Article
Publication Acceptance Date: 5/3/2006
Publication Date: 5/5/2006
Citation: Rossman, A.Y., Britton, K., Luster, D.G., Palm, M., Royer, M., Sherald, J. 2006. Evaluating the threat posed by fungi on the APHIS list of regulated plant pests. Online. Plant Health Progress doi:10.1094/PHP-2006-0505-01-PS. Available: http://www.plantmanagementnetwork.org/pub/php/perspective/2006/fungi/

Interpretive Summary:

Technical Abstract: The fungi on the APHIS List of Regulated Plant Pests were recently reviewed providing an accurate scientific name as well as the disease, plant hosts and geographic distribution for each species. The authors remained neutral on which of these fungi pose a threat to U.S. agriculture and forest resources because such an evaluation was beyond the scope of that project. An evaluation of the potential threat of fungi on the APHIS list of regulated plant pests was conducted by the federal interagency Invasive Terrestrial Arthropods and Pathogens (ITAP) Subcommittee on Plant Pathogens. The pathogens are divided into the following groups: 1) dangerous threat to crop plants and forests, 2) threat to plants of horticultural plants or crops/plants of minor economic importance, 3) already established in the U.S., 4) threat to crops not grown in U.S., and 5) not enough known to determine threat. Out of the 51 species listed, 23 of the fungi on the APHIS Regulated Plant Pest List fall into the first two groups. Attention should be paid to preventing the entry of these fungi. Interestingly, almost 60% of these are rust fungi. In synthesizing the geographic distribution of these fungi, all of these species occur in Asia except the two species of Uromyces on Gladiolus. It would appear that Asia serves as a source for pathogens that threaten U.S. agriculture although many occur elsewhere in the world as well especially in Europe where the fungi are more well-known. Many of these pathogens could enter the U.S. on nursery stock particularly those on horticultural crops. A number of these fungi occur on living forest trees. The cause of Karnal bunt, Tilletia indica, on wheat has a restricted distribution in the United States and Mexico as well as Asia and causes limited lost of quality. The fungal species about which not enough is known to determine if they are a threat should be the subject of research.