AFLP-based genetic diversity assessment of global sweetpotato (Ipomoea batatas (L.) Lam.) germplasm resources progress toward the development of a sweetpotato core collection /

by 1978- Bruckner, Adam Wesley

Bruckner, Adam Wesley. AFLP-based Genetic Diversity Assessment of Global Sweetpotato (Ipomoea batatas (L.) Lam.) Germplasm Resources: Progress Toward The Development of a Sweetpotato Core Collection (Under the direction of Craig Yencho and Bryon Sosinski). Sweetpotato (Ipomoea batatas (L.) Lam) is an extremely diverse and important crop ranking seventh in terms of global production. It is grown throughout the world as a staple crop, and is particularly important in tropical developing countries due to its wide adaptability as well as its enormous potential for preventing malnutrition. The International Potato Center (CIP) in Lima, Peru and the USDA-ARS Plant Genetic Resources Conservation unit (PGRCU) in Griffin, Georgia are the most important sweetpotato gene banks worldwide. Roughly 7,000 and 750 accessions are present in each, respectively. Both collections have been characterized for many phenotypic traits of economic importance, and they are very important in terms of germplasm conservation, as they represent a vital resource for breeders seeking future genetic improvement of sweetpotato. The molecular genetic diversity present in each collection, however, is poorly understood. In this study, 775 accessions from the PGRCU collected from various countries were sampled and fingerprinted using AFLP markers derived from 10 primer pair combinations. A total of 183 polymorphic and clearly scorable bands were generated. Using polymorphisms and phylogenetic software (PAUP and NTSysPC), we were able to clearly distinguish a different banding pattern for each of the 775 accessions. A Neighbor-Joining phylogram was constructed and revealed 6 base clades with no region specificity. Analysis of molecular variance (AMOVA) was carried out using the software program Arlequin. The within-region variation at 97.94% was the major source of molecular variance. Pairwise genetic distances between regions were calculated and the smallest distance was between the Caribbean and Central America and the greatest distance was between the Pacific Islands and South America. Principle coordinate analysis (PCO) was performed by NTSysPC and several clusters of germplasm were noted. This research indicates that there is an abundance of genetic diversity present in sweetpotato. AFLP-based Genetic Diversity Assessment of Global Sweetpotato (Ipomoea batatas (L.) Lam.) Germplasm Resources: Progress Toward The Development of a Sweetpotato Core Collection. By Adam Wesley Bruckner A thesis submitted to the Graduate Faculty of North Carolina State University In partial fulfillment of the Requirements for the Degree of Master in Science Department of Horticultural Science Raleigh, NC 2004 Approved by: _______________________________________________________________ Craig Yencho, Ph.D. Co-Chair of Advisory Committee _______________________________________________________________ Bryon Sosinski, Ph.D. Co-Chair of Advisory Committee _______________________________________________________________ Jenny Xiang, Ph.D. Personal Biography Adam Wesley Bruckner was born on September 27th, 1978 in Richmond County in Augusta, Georgia. He was a student in the public school system there until the age of 10, when he moved to a small town in Western North Carolina, where he was enrolled in a small public school where kindergarten through high school were taught. Adam then transferred to a private high school in Asheville, North Carolina. He graduated from The Asheville School in June of 1997. From there he attended North Carolina State University for his Bachelors of Science in Biological Sciences and his Masters of Science in Horticultural Science. While an undergraduate student, Adam took part in many on campus activities, getting involved in the Turlington Hall Council where he served a term as Secretary and two terms as President. He did some work in the NCSU Genome Research Lab, where Adam worked under Bryon Sosinski, who later became one of his co-chairs along with Craig Yencho. They along with his other committee member, Jenny Xiang, have guided Adam and given advice along the way. ii