In this study the response to culture in liquid medium of axillary shoots of two woody species, chestnut and willow, has been compared. Both species differ in their recalcitrance to micropropagation, especially in their rooting and acclimatization abilities. Parameters such as explant type, supporting material, bioreactor type, number of immersions and/or aerations were tested. Continuous and temporary immersion systems have been applied to both species and several differences were detected. Hyperhydricity was not observed in willow shoots cultured in liquid medium with aeration, but this disorder affected chestnut cultures unless supporting materials as rockwool cubes were used. Besides, willow shoots rooted spontaneously in liquid culture, whereas chestnut shoots required an auxin treatment. In spite of these differences, both species showed better performance in liquid culture than in semi-solid medium, and shoots from an adult willow genotype and from eight selected chestnut genotypes (hybrids of European and Asian chestnuts) were successfully rooted and acclimatized.

Peer reviewed