Callus induction from in vitro leaves of Juglans regia ‘Lvbo’

The effects of walnut (Juglans regia L.) culture in the dark and the types and ratio of plant growth regulators on callus induction were studied.
In vitro leaves were used as explants.
There was a significant influence of dark incubation time on leaf callus formation.
After 2 weeks of dark, the rate of leaf callusing was 100%. Increasing the period in darkness, inhibition of callus formation was observed.
Low concentration of TDZ (2.0 to 4.0 mg L^-1) promoted the formation of leaf callus but high concentrations (8.0 to 10.0 mg L^-1) inhibited the formation and browning of leaf callus and made the structure of the callus more porous.
In addition, formation of callus was promoted by 2,4-D, IBA and NAA, but responses were opposed at low or high concentrations.
These suggest that darkness and hormone changes the direction of leaf development.
By changing the proportion of endogenous hormones in explants, development of explants changed from vegetative growth to reproductive growth, so that cell differentiation went toward dedifferentiation.

XXIX International Horticultural Congress on Horticulture: Sustaining Lives, Livelihoods and Landscapes (IHC2014): International Symposium on Micropropagation and In Vitro Techniques

H.X. Li, S.Y. Cao

dark culture, 2,4-diclorofenoxyacetic acid, indole butyric acid, naphthylacetic acid, plant growth regulators, dark culture, thidiazuron

https://doi.org/10.17660/ActaHortic.2016.1113.19