Development of Crape Myrtle Germplasm OF with Resistance to Cercospora Leaf Spot (CLS) and Powdery Mildew
Southern Horticultural Research
2012 Annual Report
1a.Objectives (from AD-416):
To screen crape myrtle germplasm for host plant resistance to Cercospora Leaf Spot (CLS) and powdery mildew. Emphasis will be placed on maintaining germplasm under ambient field conditions and other horticultural necessities.
1b.Approach (from AD-416):
Crape myrtle controlled crosses and commerical clones will be placed at the cooperator's location and will be screened for CLS and powdery mildew. Evaluations will be made by the cooperator and by ARS scientists throughout the evaluation season each year. Germplasm with host plant resistance will be tested further in subsequent experiments.
Screening for resistance to powdery mildew and Cercospora Leaf Spot (CLS) continues on 110 elite seedlings selected from 2,000 original crape myrtle seedlings. Selections are rated for disease symptoms at least two times during growing season. Three selections were made and propagated during the 2011 growing season as potential candidates for release, and also had a dry spring which delayed flowering. Little powdery mildew was observed on other crape myrtle clones growing in proximity to the test area but CLS pressure in the fall was severe. Selections will be screened again and compared to plants selected at Poplarville, MS.