2018 ASHS Annual Conference

The American persimmon (Diospyros virginiana) is a tree fruit native to the forests of Kentucky. The golden orange fruit are sweet when fully ripened and astringency is reduced. There are two races of persimmon, a tetraploid (60 chromosome) race is centered in the southern Appalachian mountains and adjacent areas, and a hexaploid (90 chromosome) race occupies the range north and west of the tetraploid range. Many current American persimmon varieties have been selected in the wild and are thought to be in the 90 chromosome race. American persimmon improvement began in the late 19th century with the work of Dr. James Troop at Purdue University. In 1880, the first named American persimmon cultivar, Early Golden, was selected out of the wild in Illinois. James Claypool continued breeding of American persimmon in the 1970’s. Over the course of 20+ years Claypool evaluated over 2,000 trees and has made a number of cultivar releases. The objective of this study was to examine the ploidy level of Claypool selected American persimmon germplasm to determine if these varieties contain both the 60 and 90 chromosome races of persimmon as compared to commercially available varieties using flow cytometry. Leaf samples were collected from 18 Claypool selections and 10 commercially available cultivars from the budwood mother blocks at England's Orchard and Nursery in McKee, Kentucky. Flow cytometer analysis of the leaf samples showed all Claypool selections, including Dollywood, Elmo (A-118), F-34, F-62, H-118 Early Jewel, H-120, H-55a, H-55a, H-63a Claypool, I-115, J-127, J-59 Claypool, K1, K2, K6, Prairie Star, Prairie Sun, as well as the non-Claypool selected cultivars Early Golden, Garretson, Golden Supreme, Meader, Mohler, NC-10, and Yates were all from the 90 chromosome strain. Three non-Claypool selected commercial cultivars were from the 60 chromosome strain: Enis Seedless, Weeping, and Sugar Bear. This data supports that the 90 chromosome strain is also strongly represented in the high quality material of the Claypool germplasm that was selected.