Early performance of micropropagated trees of several Malus and Prunus cultivars on their own roots

Early performance (6–8 yr) of Macspur McIntosh, Golden Delicious, and Spartan apple (Malus domestica Borkh.); Fairhaven peach [Prunus persica (L.) Batsch.]; Montmorency sour cherry (P. cerasus L.); and Lambert sweet cherry (P. avium L.) trees, tissue cultured (TC) on their own roots, was compared with that of the same cultivars budded on commercially used rootstocks. TC trees of all apple cultivars were similar in size to trees budded on Antonovka seedling or M.4 and exceeded the size of trees budded on M.26. They were delayed in flowering and in cropping compared with trees budded on M.26 and M.4. No difference in titratable acidity, soluble solids, flesh firmness, weight, flavor, and color between fruit from TC trees and from trees on M.4 and Antonovka seedlings was detected in 1 yr of measurement. However, fruit from TC Golden Delicious was more russeted and fruit from TC Spartan had more soluble solids. The difference in fruit appearance between TC and budded trees may result from a root-stock effect or a difference in budwood source, because Spartan fruit from trees on M.4 was more russeted than Spartan fruit from TC trees, but was not different from Spartan fruit from trees on Antonovka seedling. Trees of Macspur McIntosh on TC M.26 and on stool-layered M.26 were similar in size and yield efficiency. TC Fairhaven was larger in size than Fairhaven on Siberian C seedling, but was less yield efficient. No difference in fruit size, flesh firmness, or color was detected between fruit harvested from peach trees on the different roots. Montmorency and Lambert TC and on F12/1 were similar in tree size, respectively, but Montmorency and Lambert TC were more yield efficient than on F12/1. Fruit of TC Lambert was lighter in color and had higher titratable acidity than that of Lambert on F12/1, perhaps a result of earlier fruit maturity. Key words: Apple, peach, sweet cherry, sour cherry, self-rooted, rootstocks