Plant regeneration from leaf explants of Adromischus nussbaumerianus Poelln. and Echeveria laui Moran et Meyran
Wojciechowicz, M., K.; Kazimierczak-Grygiel, E.; Olejnik, S.; Zenkteler, E.
Biological Bulletin of Poznan 38(1): 71-78
Leaf fragments of Adromischus nussbaumerianus and Echeveria laui were placed on the Murashige and Skoog (MS) medium with various combinations of growth regulators. The best growth of callus was observed on the MS medium supplemented with 4 mg l-1 6-benzylaminopurine and 2 mg l-1 2,4-dichlorophenoxyacetic acid. The most effective leaf and root induction was achieved for of A. nussbaumerianus callus on the MS medium with macronutrient content reduced four times, with the addition of 1 mg l-1 zeatin, 1 mg l-1 beta-indoleacetic acid and 1% sucrose. On the other hand, the most effective for E. laui callus was the half-strength MS medium supplemented with 6 mg l-1 zeatin or 2 mg l-1 zeatin and 1 mg l-1 beta-indoleacetic acid for leaf and root development, respectively. Histological analysis of explants cultured in vitro showed that cell divisions leading to callus formation were initiated in the subepidermal layer of the leaf. Subsequent cell divisions were observed in deeper layers of the mesophyll. In A. nussbaumerianus cell divisions were also noticed in some epidermal cells. Additionally, in E. laui multinucleate cells were noticed in meristematic regions of callus. Transverse sections of callus showed that the first leaf primordia were initiated in callus after 2 and 8 weeks of culture in A. nussbaumerianus and E. laui, respectively. This experiment resulted in full regeneration of both species. After acclimation, young plants were planted in the soil.