Grafting Techniques for Conservation of Endangered Prunus geniculata Harper and Other Native Prunus L. Species of the Southeastern U.S., Poster Board #153

The genus Prunus L. is economically important source of fruit such as plums, cherries, almonds, apricots and peaches. Grafting techniques are commonly used to propagate superior commercial cultivars. The desired scion genotype is grafted onto a rootstock. Native wild Prunus species have been previously used as rootstocks for grafting commercial cultivars. However, the use of grafting techniques for conservation, restoration, and maintenance of native wild Prunus species has been not previously reported. North America is a center of diversity for plum species. Several plum species are listed as endangered with seeds being the primary means of propagation. The use of different grafting techniques for the nondestructive sampling, preservation and propagation of wild native Prunus species was the main objective of this study. A total of 94 P. geniculata, 20 P. umbellata Elliot, 14 P. angustifolia Marsh., and 5 P. americana Marsh. genotypes, native to southeastern US, were grafted using a modified-veneer and T-budding techniques. Two rootstocks, ‘Sharpe’ plum and P. cerasifera plum previously grafted onto Okinawa peach, were used and evaluated. Percentage bud take was measured for each genotype. ‘Sharpe’ rootstock had 36.71% and 27.96% bud take on average for modified-veneer and T-budding, respectively. P. cerasifera / Okinawa rootstock had 3.70% and 3.57% bud take on average for modified-veneer and T-budding, respectively. Grafting proved to be a feasible method for propagation and maintenance of wild Prunus species, particularly of P. geniculata, a federally endangered species with low seedling recruitment.