Nuclear DNA integrity of cryopreserved embryonic axes of Anadenanthera colubrine (Vell.) Brenan

Abstract

Storage in liquid nitrogen is an useful method for the preservation of plant species for unlimited periods of time. The objective of this work was to evaluate the nuclear DNA content of embryonic axes of Anadenanthera colubrine upon storage in liquid nitrogen. Embryonic axes were stored in the absence and presence of different concentrations of DMSO and glycerol. Nuclear DNA content and integrity were evaluated using flow cytometry. Intact nuclei were observed in all treatments (%G1). Axes stored in cold chamber were not perfectly cryopreserved because a relatively high percentage of nuclei showed a reduction in DNA content compared to the control (standard). In contrast, axes stored in liquid nitrogen in the absence and presence of cryoprotectants were much better preserved. The use of chemical cryoprotectants resulted in an increase of intact nuclei from cryopreserved embryonic axes. High concentrations of the cryoprotectant may therefore be beneficial for the conservation of the nucleus integrity of A. colubrine embryonic axes.