ISHS Acta Horticulturae 596: VIII International Symposium on Pear
IN VITRO PRODUCTION OF VIRUS-FREE PEAR PLANTS |
| Authors: | S. Zilka, E. Faingersh, A. Rotbaum, Y. Tam, S. Spiegel, N. Malca |
| Keywords: | Pyrus communis, tissue culture, thermotherapy, virus elimination |
| Abstract:
Under plant protection regulation the introduction of virus-infected cultivars is not permitted. In most cases, the only way to introduce new imported distinguished cultivars, found infected under the quarantine indexing procedures, is virus elimination and production of virus-free plants. Pear (Pyrus communis cvs. Bon Rouge and Cascade) were imported to Israel and indexed on several plant indicators under the quarantine procedures. ‘Bon Rouge’ induced virus symptoms on Spy 227 (Malus pumila) indicator. ‘Cascade’ plants showed symptoms indicative of a viral infection. The viruses were not identified. Apical parts of new flush stem, containing 2 axillary buds, were disinfected and cultured on Almehdi and Parfitt establishment medium, at efficiency of 75% for ‘Bon Rouge’ and 67%, for ‘Cascade’, respectively. The cultures were adapted to proliferation medium at proliferating rate of 7-8 shoots in subculturing intervals of 4-6 weeks. Thermotherapy (20 days of 42/31°C, 16/8h photoperiod, respectively) was applied to elongated shoot cultures. Tips of  5 mm of the survived shoots were proliferated, rooted at efficiency of 84 % for ‘Bon Rouge’ and 79 % for ‘Cascade’ and acclimated.
The regenerated plants were reindexed on the same series of plant indicators that had been used before the procedures taken for virus elimination.
All the reindexed clones were found free of virus infection and have been used as plant material source for certificate virus free plants.
| |
Download Adobe Acrobat Reader (free software to read PDF files) | |
