Resistance to Take-all is Not Expressed in Wheat-Alien Chromosome Addition and Substitution Lines

Abstract

Stalk and petiole rot of herbaceous ornamental perennials, caused by S. rolfsii var. delphinii, is a widespread disease in landscape plantings and nursery production fields in the Midwest United States. A better understanding of perennation of the pathogen could aid in development of more effective management recommendations. Sclerotia of S. rolfsii var. delphinii were produced on strips of inoculated cotton batting placed on moistened sand in a plastic crisper. After one week at 27°C, sclerotia were removed, sealed in nylon mesh bags, and the bags were buried immediately below the soil surface and at 15-cm and 30-cm depths at two locations in Iowa in September 2001. Germination of sclerotia was quantified in October and November 2001 and in April, May, June, and July 2002 by plating recovered, surface-sterilized sclerotia on carrot agar amended with antibiotics. Survival was highly variable but in June and July was greatest at the soil surface (~50%). This is the first documented evidence that S. rolfsii var. delphinii will overwinter in the Midwest and survive a sufficient length of time to cause disease in the next growing season. Accepted for publication 6 October 2003. Published 24 November 2003.