In vitro propagation of Japanese pear (Pyrus serotina Rehd.) cvs. ‘Nijisseiki’, ‘Shinsui’, ‘Kosui’, ‘Hosui’ and ‘Yagumo’ was investigated.
1. Shoot tips (<0.5mm) of each cultivar were cultured in half-strength Murashige and Skoog medium (1/2MS) containing 1mg/l BA and 0.1mg/l IBA. Shoot growth and proliferation of ‘Shinsui’ and ‘Nijisseiki’ were less than with other cultivars at the culture establishment stage, but gradually became better after 4 subcultures.
2. The best agar for shoot growth and proliferation was powder agar. The best basal medium was woody plant medium (WPM) for ‘Nijisseiki’, and ‘Osa-nijisseiki’, and 1/2MS for the other cultivars.
3. Rooting from shoots occurred after the 7th subculture and the percentage of rooting gradually increased by repeated subcultures. The best rooting was obtained when shoots were pretreated on modified Linsmaier ahd Skoog medium (1/2 Macro-LS) supplemented with 162mg/l phloroglucinol (PG) and 2mg/l IBA and kept in the dark for 5 days, then transplanted to hormone-free 1/2 Macro-LS supplemented with 162mg/l PG.
4. Rooted plantlets were transferred to peatmoss in containers and were gradually acclimatized in a growth chamber under 24h photoperiod for 2 weeks. After being transplanted to soil, plantlets of each cultivar began to grow well.