SOMATIC EMBRYOGENESIS AND EMBRYO MATURATION IN PERSIAN WALNUT

Embryogenesis potential of different tissues (anther, cotyledon, endosperm, leaf, and petiol) of Persian walnut (Juglans regia L.) was studied.
Different tissues had various callus production potential, however calluses from immature cotyledons were embryogenic under our experiment conditions.
Cotyledons derived from nuts harvested 6 weeks after pollination produced embryogenic calluses in most studied cultivars. ‘Vina’ cotyledons had the highest rate of embryogenesis (28.5%) followed by ‘Chandler’ (28.5%), ‘Serr’ (18.2%), ‘Hartly’ (15.4%), ‘Z60’ (6.6%) and ‘Z67’ (0%), respectively.
Z67 genotype produced embryogenic calluses only when cotyledons were derived from nuts harvested 9 weeks after pollination.
Since walnut somatic embryos usually do not produce both normal roots and shoots, effect of abscisic acid on maturation of embryos was also investigated.
Abscisic acid concentrations more than 2 mg/l could led to normal maturation of embryo.
Early stage of embryo development was recognized as the best stage for abscisic acid treatment.

V International Walnut Symposium

K. Vahdati, M. Jariteh, V. Niknam, M. Mirmasoumi, H. Ebrahimzadeh

walnut, Juglans regia, embryogenesis, embryo, maturation, germination, abscisic acid

https://doi.org/10.17660/ActaHortic.2005.705.24