Blueberry cultivars have traditionally been identified based on the evaluation of sets of morphological characters; however, distinguishing closely related cultivars remains difficult. In the present study, we developed DNA markers for the genetic fingerprinting of 45 blueberry cultivars, including 31 cultivars introduced from the United States Department of Agriculture. We obtained 210 random amplified of polymorphic DNA (RAPD) markers using 43 different primers. The number of polymorphic bands ranged from three (OPG-10 and OPQ-04) to eight (OPR-16), with an average of five. A cluster analysis performed with the unweighted pair group method using arithmetic averages produced genetic similarity values among the blueberry cultivars ranging from 0.53 to 0.85, with an average similarity of 0.68. A dendrogram clustered the 45 blueberry cultivars into two main clusters, with a similarity value of 0.65. Cluster I consisted of four rabbiteye cultivars (Pink Lemonade, Alapaha, Titan, and Vernon) and the Ashworth northern highbush cultivar. Cluster II consisted of 31 northern highbush cultivars, eight southern highbush blueberry cultivars, and Northland half-highbush blueberry cultivar. Fifty five RAPD fragments selected were sequenced to develop sequence-characterized amplified region (SCAR) markers, resulting in the successful conversion of 16 of 55 fragments into SCAR markers. An amplified polymorphic band has the same size as the RAPD fragment or smaller according to the primer combinations in the 16 SCAR markers. Among these markers, a combination of 11 SCAR markers provided sufficient polymorphisms to distinguish the blueberry cultivars investigated in this study. These newly developed markers could be a fast and reliable tool to identify blueberry cultivars.
Grapevine cultivars have traditionally been identified based on the morphological characteristics, but the identification of closely related cultivars has been difficult because of their similar pedigree backgrounds. In this study, we developed DNA markers for genetic fingerprinting in 37 grapevine cultivars, including 20 cultivars bred in Korea. A total of 180 randomly amplified polymorphic DNA (RAPD) markers were obtained using 30 different primers. The number of polymorphic bands ranged from three (OPG-08 and OPU-19) to nine (OPV-01 and UBC116), with an average of six. RAPD markers were used in cluster analysis performed with the unweighted pair-group method of arithmetic averages (UPGMA). The average similarity value was 0.69 and the dendrogram clustered the 37 grapevine cultivars into five clusters. The relationships among the grapevine cultivars were consistent with the known pedigrees of the cultivars. The 50 RAPD fragments selected were sequenced for the development of sequence-characterized amplified region (SCAR) markers. As a result, 16 of 50 fragments were successfully converted into SCAR markers. A single polymorphic band, the same size as the RAPD fragments or smaller, was amplified depending on the primer combinations in the 14 SCAR markers, and codominant polymorphisms were detected using the SCAR markers G119_412 and GB17_732. Among these markers, combination of 11 SCAR markers, GG05_281, G116_319, G146_365, G119_412, GW04_463, G169_515, G116_539, GV04_618, GV01_678, GG05_689, and GB17_732, provided sufficient polymorphisms to distinguish the grapevine cultivars investigated in this study. These newly developed markers could be a fast and reliable tool for identifying grapevine cultivars.