MUTATION BREEDING BY ION BEAM IN LETTUCE (LACTUCA SATIVA L.) USING AN IN VITRO REGENERATION SYSTEM
Lettuce is one of the most important vegetable crops for factory production under artificial conditions. Because a shorter harvesting period is desirable, we tried to select fast-growing lines using ion beam mutation breeding, which is expected to generate many mutation effects. Among 27 lettuce genotypes, we selected two cultivars, Papa Lettuce (PL) and Red Salad S (RS), which had high organogenetic capacity on media containing 1 µM NAA and 1 µM BAP. Petri dishes with leaf explants were exposed to H+ and 12C6+ beams accelerated with a multipurpose synchrotron and tandem accelerators. The doses were 1, 3, 5, or 10 Gy. After 4 weeks in culture, the number of regenerated shoots was recorded, and plants were subcultured on hormone-free media. Shoot regeneration was suppressed by radiation higher than 5 Gy of H+ in RS, but less suppression was observed in PL. Low-dose irradiation with H+ enhanced shoot regeneration. 12C6+ irradiation had a higher suppression effect on shoot regeneration, and all RS explants died after 10 Gy irradiation. Some lines selected from the M2 generation showed faster growth than the original cultivars.
Ohki, S. and Hatashita, M. (2012). MUTATION BREEDING BY ION BEAM IN LETTUCE (LACTUCA SATIVA L.) USING AN IN VITRO REGENERATION SYSTEM. Acta Hortic. 961, 285-290
H+, 12C6+, organogenesis, growth enhancement, plant factory