Seed Gall of Wheat

Seed gall of wheat is one of the earliest wheat diseases and the first disease caused by a plant pathogenic nematode described. It's caused by the seed gall nematode Anguina tritici. Rye and wheat are both hosts for this disease, but wheat is most often affected. Seed gall can be found in Asia, India, Yugoslavia, Southeastern Europe, and the Middle East. In the past it was found in the Southeastern United States, but has since been declared not to occur in the U.S.

Infected wheat kernels called galls or cockles either fall to the ground where they serve as an inoculum source for the following season or are harvested with healthy kernels. Unclean seed containing galls planted the following season can also serve as an inoculum source. In either case second stage juveniles emerge from galls in soil and climb up wheat seedlings via water films feeding on plant tissue along the way. Eventually, the juveniles penetrate undifferentiated flower tissue stimulating gall formation. Several galls can form per kernel. Juveniles within the galls mature, mate, and produce and lay eggs there. These eggs hatch and the second stage juveniles remain in galls for infection next season. In the case of dry environmental conditions, the juveniles can remain quiescent and survive for several years. This disease is favored during wetter conditions.

• Anguina tritici can vector a bacterium Clavibacter tritici which causes yellow ear rot of wheat and is toxic to cattle and sheep.
• Anguina tritici is reported to no longer exist in the U.S. due to seed cleaning procedures which remove galls from normal wheat seed. In lesser developed countries without these seed cleaning procedures, A. tritici can cause losses up to 35-65% in rye and 20-50% in wheat.

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Disease Cycle

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Symptoms

Plant Health Management

Use clean seed. Separate galls from seed via seed cleaners and/or floatation.

Two years rotation with a non-host crop. This allows juveniles to be released from galls with moisture.

Avoid wet soil conditions.

References

Wiese, M. V. Seed-Gall Nematode in Compendium of Wheat Diseases, Second Edition. 1987 by APS Press.

Useful Links

University of Nebraska
UC Davis

Caveat

Material contained on the Links from the page are the responsibility of the linked page's author(s).

This page was researched and drafted by: Jennifer Fleer, Department of Plant Pathology, University of Nebraska-Lincoln

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This page is authored and maintained by:
Dr. J.E. Partridge, Department of Plant Pathology, University of Nebraska-Lincoln

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Copyright (C)2003 J.E. Partridge, University of Nebraska-Lincoln. All Rights Reserved.