May 15, 2006
From: ProMED-mail<promed@promedmail.org>
Source: plantmanagementnetwork.org and Plant Health Progress doi:10.1094/PHP-2006-0505-01-PS [edited] <http://www.plantmanagementnetwork.org/pub/php/perspective/2006/fungi/>
 

Evaluating the threat posed by fungi on the APHIS List of Regulated Plant Pests
Amy Y. Rossman, Systematic Botany & Mycology Laboratory, USDA Agricultural Research Service, Beltsville, MD 20705 and Chair, Federal Interagency Committee on Invasive Terrestrial Animals and Pathogens Subcommittee on Plant Pathogens; Kerry Britton, USDA Forest Service, Arlington, VA 22209; Doug Luster, Foreign Disease-Weed Science Research Unit, USDA Agricultural Research Service, Ft. Detrick, MD 21702; Mary Palm, Systematic Botany & Mycology Laboratory, USDA Animal and Plant Health Inspection Service, Beltsville, MD 20705; Matthew H. Royer, Emergency and Domestic Programs, USDA Animal and Plant Health Inspection Service, Riverdale, MD 20737-1234; and Jim Sherald, US Department of the Interior, National Park Service, Center for Urban Ecology, Washington, DC 20007 Corresponding author: Amy Y. Rossman. <arossman@nt.ars-grin.gov>

Drs. Erica Cline and David Farr recently [May 2006] reviewed the fungi on the APHIS Regulated Plant Pest List, providing an accurate scientific name as well as the disease, plant hosts, and geographic distribution for each species. In presenting these data they 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. However, the purpose of such a document is so that someone or some organization can do just that -- evaluate the threat posed by these fungi. Once the fungi that threaten U.S. agriculture are known, activities can be directed at preventing the entry of
those organisms. An evaluation of the potential threat of fungi on the APHIS Regulated Plant Pest List was conducted by the federal interagency Invasive Terrestrial Arthropods and Pathogens (ITAP) Subcommittee on Plant Pathogens using the data provided in Cline and Farr (1). Each species was evaluated based on the!
importance of the plant host, geographic distribution, and state of knowledge. Fungi that cause serious diseases of plants of major economic value and forest trees were considered a threat if the fungus does not occur in the United States. If the species is reported more than once in the United States and these reports are in the literature or backed by voucher specimens, the species is considered to be established in the United States. Some fungal pathogens occur on crops that are not grown in the United States but are important to the U.S. economy. For some fungi not enough is known to make an evaluation; in fact, some species have not been seen since their original description often decades ago. The pathogens that are a threat to major crop plants are as follows;

_Elsinoe australis_ on citrus; South America
_Monilinia fructigena_ on apples, pears, and peaches; Europe, Asia, South America
_Peronosclerospora maydis_ on corn; Asia, Australia, South America
_Peronosclerospora sacchari_ on sugarcane; Asia, Australia, Central America
_Peronosclerospora philippinensis_ on corn (select agent), Asia, Africa
_Scerophthora rayssiae var. zeae_ on corn (select agent), Asia
_Synchytrium endobioticum_ on potato (eradicated from US, select agent); Europe, Asia, Africa, North America (Canada)
_Thekopsora areolata_ on Prunus; Europe, Asia, Caribbean
_Urocystis agropyri_ on wheat (possibly in US); Europe, Asia, Africa, South America, Australia

Pathogens for which there is not enough known to determine threat are as follows;

_Diaporthe mali_ on apples
_Guignardia pyricola_ on apples and pears
_Gymnosporangium asiatica_ (_Roestelia koreensis_) on pear (in US based on old specimens, possible misidentifications)
_Melanomma glumarum_ on rice
_Oospora oryzetorum_ on rice (not a fungus)
_Pestalotiopsis disseminata_ on banana
_Pseudopezicula tracheiphila_ on grapes
_Rhacodiella vitis_ on grape (known only from type)
_Septoria melanosa_ on grape (reported in North America?)

Attention should be paid to preventing the entry of these fungi. Interestingly, many of these are rust fungi. In synthesizing the geographic distribution of these fungi, all of these species occur in Asia. 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. 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 loss of quality. The fungal species about which not enough is known to determine if they are a threat should be the subject of research.

Literature Cited
1. Cline, E. T. and Farr, D. F. 2006. Synopsis of fungi listed as regulated plant pests by the USDA Animal and Plant Health Inspection Service: Notes on nomenclature, disease, plant hosts, and geographic distribution. Online. Plant Health Progress
doi:10.1094/PHP-2006-0505-01-DG.

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ProMED-mail
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[An evaluation of fungal pathogens that could pose a potential threat to crops in the USA and which are of interest to ProMED-mail is provided above. It was edited down from the full article (see main link) which is based on the APHIS Regulated Plant Pest List. The full article included fungal pathogens of trees and ornamental plants. The evaluation was conducted by the federal interagency Invasive Terrestrial Arthropods and Pathogens (ITAP) Subcommittee on Plant Pathogens using the data provided in Cline and Farr. Fungi that cause serious diseases of plants of major economic value were considered a threat if the fungus does not occur in the United
States. The authors comment on the fact that many of the pathogens are rust fungi and that all can be found causing diseases in Asia. The only previous posting found in ProMED-mail using 'APHIS' and 'Regulated' deal with karnal bunt, and they have not been included here.

Links:
<http://www.aphis.usda.gov/ppq/regpestlist/ >
<http://www.plantmanagementnetwork.org/php/elements/sum.asp?id=5218&photo=2935>
- Mod.JAD]