In vitro germination and chemical composition of Zantedeschia aethiopica Callus

Abstract

Zantedeschia aethiopica is often used for cut flowers. However, seedling production is very limited, mainly due to diseases. The objective of this work was to develop an in vitro propagation protocol for the species and to analyse its callus chemical composition. Seeds obtained from mature and immature fruits were inoculated in half-strength MS and WPM culture media supplemented with 15 g L-1 sucrose. Different GA3 concentrations (0.0, 0.2, 0.4, 0.6 and 0.8 mg L-1) were added to the MS medium in the presence of 15.0 g L-1 sucrose. For callus induction, nodal segments were inoculated on MS medium supplemented with 2,4-D (0.0, 1.0, 2.0 and 3.0 mg L-1) and 15 g L-1 sucrose. For callus chemical analysis, total phenols, starch, total soluble sugars, reducing and non-reducing sugars, lipids and protein were quantified. Seeds from immature fruits presented 33% germination in WPM medium while seeds from mature fruit presented 24% germination on MS medium. Regarding the use of MS medium plus 15 g L-1 sucrose with different GA3 concentrations, the higher germinated rate, using immature (20%) or mature fruit seeds (10%), were obtained with 0.8 or 0.2 mg L-1 GA3, respectively. The callus induction occurred in media supplemented with 1.0 mg L-1 (53%) and 2.0 mg L-1 (47%) of 2,4-D. The callus chemical composition was as follows: total phenols (802.47 mg 100 g-1), starch (19.8 g 100 g-1), total soluble sugar (3.1 g 100 g-1), reducing sugar (1.2 g 100 g-1), non-reducing sugar (1.8 g 100 g-1), ether extract (1.0%) and protein (20%). These compounds may help the understanding of cellular dedifferentiation processes that take place in Z. aethiopica species.