Co-Authors:
Zilkah, S., Institute of Horticulture, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
Faingersh, G., Institute of Horticulture, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
Rotbaum, A., Institute of Horticulture, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
David, I., Institute of Horticulture, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
Spiegel, S., Institute of Plant Protection, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
Tam, Y., Institute of Plant Protection, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
Rieger-Stein, A., Institute of Plant Protection, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
Abstract:
'Hermosa' is one of the major mid-season peach cultivars in Israel. This cultivar has been found widely infected with prunus necrotic ring spot virus (PNRSV). Usually, no conspicuous phenomena have been noticed by the growers. The present work has been aimed to examine, under controlled comparison, whether the performance of the infected 'Hermosa' trees differs from that of virus-free trees. Shoot culture system, including establishment, propagation and rooting, have been developed for 'Hermosa'. In vitro thermotherapy and shoot-tip culturing have been applied for virus eradication. Virus-free (as determined by ELISA) cultures were regenerated to intact plants. Scions derived from virus-free or virus-infected cultures, and scion derived from virus-infected cut-wood were grafted on virus-free rootstocks, creating three types of plants. Two years after planting in the field the virus-free trees started to show an advantage at tree growth, as was shown by measurements of trunk circumference. This advantage continued for the following 4 years, in comparison to the virus-infected trees, from both in vitro and ex vitro sources. In 1999, results showed a significant increase in yield and fruit size for the virus-free trees in comparison to the infected ones derived from the corresponding in vitro sources. After 7 years of growth, the virus-free trees remained uninfected by PNRSV. These data confirmed the favorable performance of the virus-free 'Hermosa' peach trees over the infected ones.