Development of advanced technologies for germplasm conservation of tropical species.
Drew R., Azimi M., Ashmore S.
Author Affiliation: School of Biomolecular and Biomedical Science, Griffith University, Nathan Campus, Nathan, QLD 4111, Australia.
: 97-100
Abstract : Pawpaw (cultivars 70 and K18) shoot tip and mango (cv. Kensington) somatic embryo (SE) cryopreservation was evaluated, and the effects of the following factors were studied: age of in vitro-cultured plants, duration of pre-culture of shoot tips prior to vitrification treatment, duration and temperature of PVS2-treatment, and concentration of growth regulators (BAP [benzyladenine] and GA3 [gibberellic acid]) in the recovery medium after cryopreservation. The effects of light on the recovery of shoots after cryopreservation were also investigated. Success rates were genotype-dependent, but shoot recovery of between 60 and 70% was obtained for some genotypes. The plant growth regulators improved the rate of recovery and growth rate of the recovered shoot tips. Dark storage (1, 2 and 4 days) resulted in 45% recovery, compared with 55% recovery in the absence of dark incubation. The shoot tips failed to recover when they were incubated in the dark for 6 days. For mango, SEs were induced from the nucellar tissue of immature fruits. The rapid proliferation of secondary SEs was achieved. Cryopreservation of SEs is at a preliminary stage; however, live SEs were recovered after liquid nitrogen treatments.