In vitro phytosanitary control and improvement, as well as micropropagation of peach rootstocks and cultivars

• Published in: Acta horticulturae no. 962; pp. 187 - 193
• Main Authors: Balla, I, Kirilla, Z, Laimer, M, Kriston, E
• Format: Journal Article
• Language: English
• Published: International Society for Horticultural Science 01-01-2012
• Subjects: bioassays; clones; cultivars; health status; iron; meristems; micropropagation; new methods; pathogens; peaches; photoperiod; Phytoplasma; Plum pox virus; polymerase chain reaction; Prunus; rootstocks; shoots; sugars; viability; viruses
• ISSN: 0567-7572; 2406-6168
• DOI: 10.17660/actahortic.2012.962.27

Continuously growing demand for healthy planting material of new stone fruit cultivars resulted in the development of efficient micropropagation procedures. Different rootstocks and cultivars have different requirements, even under in vitro conditions. Optimal levels of macroelements, iron and sugar were determined for successful plant production. The health status also has an important influence on the viability of in vitro cultures. Molecular techniques offer new methods for the detection of the most dangerous pathogens of Prunus to control the health status. Tissue cultures were examined by IC-RT-PCR and PCR for the absence of Plum pox virus (PPV) and European Stone Fruit Yellow phytoplasma (ESFY), which cause the most serious losses for the producers and cannot be cured after infections occur. In vitro cultures of infected clones were cured by thermotherapy in a growth chamber at 38/36°C under a 16/8 photoperiod for 15-20 days. Meristem tips of surviving shoots were excised following thermotherapy and regenerated to vigorously growing plantlets. The phytosanitary status of heat-treated cultures originating from single meristems were tested by IC-RT-PCR and by bioassays with acclimatized plants grown under in vivo conditions in a screenhouse. Examinations ensured the success of in vitro thermotherapy, since both the IC-RT-PCR as well as the bioassays yielded negative results. The use of sensitive methods for virus and phytoplasma detection decreases the time required for virus elimination procedures. These methods are valuable for reducing the impact of virus or phytoplasma infections in European stone fruit planting material.