Addition of Blue Mold Resistance to KTTII Burley Tobacco Varieties

The Kentucky-Tennessee Tobacco Improvement Initiative (KTTII) has made considerable progress in variety development since its inception in 1999, with six new burley varieties having been released since the year 2002. These new varieties have been readily accepted by tobacco growers, comprising approximately 75-80% of the US crop annually. As a result of consolidation and increased production that has occurred over the last 10 years, without these disease resistant varieties it would be difficult for producers to maintain crop rotation practices that are a vital part of the management strategies for soil-borne diseases. Most of the burley varieties released by KTTII have high resistance to black root rot, wildfire, tobacco mosaic virus, tobacco etch virus, tobacco vein mottling virus, and potato virus Y; they also have moderate to high resistance to race 1 black shank. Some of these varieties also contain high resistance to race 0 black shank and moderate to high resistance for fusarium wilt. However, among these varieties, only KT 206LC has moderate resistance to blue mold. Blue mold is generally a sporadic disease in the United States but it can cause substantial economic damages when epidemics occur under ideal weather conditions. Even in seasons when a blue mold epidemic does not occur, the use of preventative fungicide sprays can cost tobacco growers thousands of dollars. Although the sporadic nature of the disease makes the release of a blue mold resistant variety that is inferior in terms of yield or other desirable disease resistance impractical, the addition of blue mold resistance to otherwise outstanding varieties that have high resistance to black shank and fusarium wilt is highly desirable. The proposed research project would use marker assisted selection techniques and an early flowering trait to add blue mold resistance to TN 90, KT 204, KT 206, KT 209, KT 210, and KT 212; all of these varieties are well adapted, black shank resistant varieties that are already being utilized by burley growers. The successful completion of this project would greatly reduce the risk of catastrophic losses due to a blue mold epidemic, and eliminate the stress and economic burden of applying fungicides when a potential blue mold outbreak is forecast.