Author
BIDANI, AMIRA - Faculty Of Sciences Of Gabes | |
Hummer, Kim | |
LYRENE, PAUL - University Of Florida | |
OLMSTEAD, JIM - University Of Florida | |
Bassil, Nahla |
Submitted to: Acta Horticulturae International Symposium on Vaccinium Culture
Publication Type: Abstract Only Publication Acceptance Date: 2/23/2017 Publication Date: N/A Citation: N/A Interpretive Summary: The United States Department of Agriculture (USDA)-Agricultural Research Service (ARS)-National Clonal Germplasm Repository (NCGR) in Corvallis Oregon preserves genetic resources of many temperate fruit crops. This genebank contains more than 1750 cultivars and wild relatives of blueberry from 39 countries. Wild species representatives from northwestern, central and south Florida, and neighboring US states were collected in multiple USDA expeditions and are being preserved at the NCGR-Corvallis. This invaluable germplasm is vulnerable to loss in the wild due to encroachment of human development. The objective of this study was to evaluate genetic diversity in 67 individuals from these southeastern US expeditions using DNA-based techniques. Fourteen of 44 tested DNA-based markers detected genetic variation in the 67 individuals representing four species. The cultivars Everblue and Johnblue were closely related. Florida 4B, a well-known breeder selection used for introducing the economically valuable low chilling trait into the highbush blueberry cultivars, was obtained from two sources. The two Florida 4B samples had different fingerprints, while two individuals with different New Jersey selection numbers had identical fingerprints. This work illustrates the importance of DNA fingerprinting in maintaining accurate and diverse germplasm collections to ensure scientific and breeding utility. Future analyses will include confirming the identity of the Florida 4B genotypes and evaluating the genetic diversity and population structure of these wild accessions. Technical Abstract: The United States Department of Agriculture (USDA)-Agricultural Research Service (ARS)-National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, USA preserves genetic resources of many temperate fruit crops, including blueberry. This genebank contains > 1,750 Vaccinium accessions from 39 countries, with cultivars and selections stored as living plants, and wild relatives stored as seed. Wild species representatives from northwestern, central and south Florida, and neighboring US states collected during multiple USDA expeditions, are preserved at the NCGR-Corvallis. This invaluable wild germplasm is vulnerable to loss due to habitat encroachment from human development. The objective of this study was to evaluate genetic diversity in 67 accessions from several domestic US expeditions. More than 44 primer pairs flanking microsatellite or simple sequence repeats (SSRs) identified in V. corymbosum were screened for polymorphism in 14 accessions of four species. Fourteen SSRs proved polymorphic and easy to score in these species and were used to estimate genetic diversity of the 67 individuals including 35 V. darrowii, 19 V. elliottii, 12 V. fuscatum, and one V. myrsinites accessions. Genetic distance was closest among the two named cultivars: V. darrowii ‘Everblue’ and ‘Johnblue’. Vaccinium darrowii Florida 4B, a well-known breeder selection used for introducing the economically valuable low-chilling trait into the cultivated highbush gene pool, was obtained from two sources. The two Florida 4B samples had dissimilar fingerprints, while two accessions of V. darrowii with different New Jersey selection numbers had identical fingerprints. Cluster analysis separated the wild accessions into species groups. This work illustrates the importance of DNA fingerprinting in maintaining accurate and diverse germplasm collections to ensure scientific and breeding utility. Future analyses will include confirming the identity of the Florida 4B genotypes, and evaluating the genetic diversity and population structure of these wild accessions. |