Molecular Approaches to Improved Breeding for Blight Resistance in Castanea

Open Access
Author:
Deitrick, Kelly Ann
Graduate Program:
Forest Resources
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
July 14, 2008
Committee Members:
  • John Edward Carlson, Thesis Advisor
Keywords:
  • chestnut blight
  • bulked segregant analysis
  • dot blot analysis
  • linkage analysis
  • Castanea
Abstract:
In 1904 the chestnut blight, caused by Cryphonectria parasitica, was introduced to North America from Asia and has devastated the chestnut population in America. The current goal of The American Chestnut Foundation is to successfully cross breed American chestnuts and Chinese chestnuts to adapt trees with resistance to the blight while retaining all other American chestnut characteristics. Molecular approaches are being employed to improve breeding techniques. This study includes Dot Blot analysis, segregation analysis, and linkage analysis of filial populations. The Dot Blot approach was used to estimate the amounts of Chinese and American chestnut DNA present in individual samples from the BC3F2 generation. Bulked Segregant Analysis was used to identify markers that are linked to blight resistance. The six new markers obtained were added to the existing F2 genetic linkage map of American by Chinese chestnut (Kubisiak et.al, 1997). Linkage analysis was also conducted on an F1 population of chestnut to compare linkage groups with the F2 linkage map. Sixteen RAPD and 2 SSR markers were used for linkage analysis on the F1 population, none of which were placed in the same arrangement as on the F2 map. These results provide new tools and insights for breeding blight resistant American chestnuts.