GENETIC VARIABILITY AMONG ACCESSIONS OF GARLIC IN THE USDA NATIONAL PLANT GERMPLASM SYSTEM

Authors: Volk, Gayle; Henk, Adam; Richards, Christopher

Submitted to: American Society of Plant Biologists
Publication Type: Abstract Only
Publication Acceptance Date: 1/20/2002
Publication Date: 3/20/2002
Citation: VOLK, G.M., HENK, A.D., RICHARDS, C.M. GENETIC VARIABILITY AMONG ACCESSIONS OF GARLIC IN THE USDA NATIONAL PLANT GERMPLASM SYSTEM. American Society of Plant Biologists. 2002. Pp25.

Interpretive Summary: The USDA National Plant Germplasm System (NPGS) maintains more than 200 clonal accessions of garlic (Allium sativum) in its collection. Garlic plants rarely produce seed and must be propagated by cloves. Garlic bulbs rarely store for more than a season using the current storage conditions so accessions are harvested and replanted in the field each year. Although a back-up collection for most seed-propagated crops is maintained at the USDA National Center for Genetic Resources Preservation in Ft. Collins, Colorado, the garlic collection is not currently backed up within the NPGS. A cryopreservation method to provide a long-term back-up for garlic has been developed and implementation will begin with the 2002 crop. The process of cryopreserving garlic is very labor intensive. By determining the extent of genetic duplication within the garlic collection, we can eliminate the effort involved in cryopreserving duplicate accessions. Since garlic exhibits a high degree of environmentally induced phenotypic plasticity, a molecular fingerprinting approach was used to identify duplicate accessions. Amplified fragment length polymorphism (AFLP) methods display between 20 and 30 informative characters per primer pair on a gel. Seven primer sets were used in this study. The repeatability of banding patterns was determined by extracting replicate samples of DNA from different cloves. Analyses have revealed duplicates in the collection. The NPGS garlic accessions were compared with more than 100 varieties of garlic that are commercially available to identify if additional accessions should be included in the national collection.

Technical Abstract: The USDA National Plant Germplasm System (NPGS) maintains more than 200 clonal accessions of garlic (Allium sativum) in its collection. Garlic plants rarely produce seed and must be propagated by cloves. Garlic bulbs rarely store for more than a season using the current storage conditions so accessions are harvested and replanted in the field each year. Although a back-up collection for most seed-propagated crops is maintained at the USDA National Center for Genetic Resources Preservation in Ft. Collins, Colorado, the garlic collection is not currently backed up within the NPGS. A cryopreservation method to provide a long-term back-up for garlic has been developed and implementation will begin with the 2002 crop. The process of cryopreserving garlic is very labor intensive. By determining the extent of genetic duplication within the garlic collection, we can eliminate the effort involved in cryopreserving duplicate accessions. Since garlic exhibits a high degree of environmentally induced phenotypic plasticity, a molecular fingerprinting approach was used to identify duplicate accessions. Amplified fragment length polymorphism (AFLP) methods display between 20 and 30 informative characters per primer pair on a gel. Seven primer sets were used in this study. The repeatability of banding patterns was determined by extracting replicate samples of DNA from different cloves. Analyses have revealed duplicates in the collection. The NPGS garlic accessions were compared with more than 100 varieties of garlic that are commercially available to identify if additional accessions should be included in the national collection.