IN VITRO PROPAGATION OF COMPACT PEAR CLONES

Compact growth habit in pear trees was obtained through in vitro irradiation and field selection.
Individuals that showed compact habit (small size, short internode, low vigor) were established in vitro and micropropagated.
Culture media were tested in order to find the most suitable medium for proliferation.
Performances of seven compact grown clones were compared with those of the two standard growth cultivars ‘Conference’ and ‘Doyenné d’Hiver’, in order to test if culture medium could be selective for compact genotypes.

Media tested contained MS salts and were supplemented with 2.2, 4.4, 8.8 or 17.6 μmol BAP. All compact clones, but STF8, had the highest proliferation rates with the highest tested concentration of BAP. This contrasted with standard cultivar response: ‘Conference’ had the highest proliferation with 4.4 or 8.8 μmol BAP. ‘Doyenné d’Hiver’ had the best results on the medium containing 4.4 µmol BAP. Both cultivars had poor results with 17.6 μmol BAP. At high levels of cytochinins the standard growth cultivars showed stress symptoms as vitrification.
Cytokinins proved to have a potential for a preliminary screening for compact mutants after mutagenesis.

VII International Symposium on Pear Growing

S. Predieri, M. Govoni

breeding, micropropagation, mutagenesis, Pyrus communis, selection, tissue culture

https://doi.org/10.17660/ActaHortic.1998.475.15