Exogenous gibberellin and cytokinin in a novel system for in vitro germination and development of African iris (Dietes bicolor)

Abstract

The availability of reliable and reproducible micropropagation systems is a decisive step to successfully propagate plant species with slow growth and low germination rate. The effect was investigated of gibberellin (GA) and cytokinin (CK) in the in vitro germination and development of Dietes bicolor (Steud.) Sweet ex Klatt. Seeds were inoculated in Water + Agar; in Murashige e Skoog (MS) medium without plant growth regulators (PGRs) and in MS medium supplemented with 1 or 2 mg L-1 gibberellic acid or 6-benzylaminopurine. The germination, growth, and architecture of the plants presented significant alterations according to the treatments. Germination percentage increased at 2 mg L-1 GA. Plants grown on the GA-supplemented medium also showed larger leaves. The presence of CK in the culture medium induced the activation of axillary shoot buds and reduced the root length. CK and GA had antagonistic effects on the thickness of the leaf tissues. The activation of multiple shoots in plants cultured with CK in the medium allowed the in vitro propagation of approximately three plants per germinated seed. The results obtained in the present study bring an unprecedented description of a germination system for a higher yield in D. bicolor micropropagation.

Micropropagation of Plum (Prunus domestica L.) in Bioreactors Using Photomixotrophic and Photoautotrophic Conditions

“…In the photomixotrophic using shoot clusters as initial explants, the shoot number and shoot length were the highest in treatments with BA 0.5 and IBA 0.5, whereas leaf size was negatively correlated. Typically, leaf size decreases with increasing cytokinin supplementation [42,63,64]. Increasing exposure of the plant material to more immersions of up to six per day increased plant growth, whereas using more frequent immersion produced hyperhydric shoots (data not shown).…”