Assessments of rooting, vegetative growth, bulb production, genetic integrity and biochemical compounds in cryopreserved plants of shallot

Shallot (Allium cepa var. aggregatum), a small bulb onion, is widely grown in the world. We previously reported a droplet-vitrification for cryopreservation of in vitro-grown shoot tips of shallot genotype ‘10603’. The present study further evaluated rooting, vegetative growth, bulb production and contents of biochemical compounds, as well as genetic stability in cryo-derived plants. The results showed no significant differences in rooting, vegetative growth, bulb production and contents of soluble sugars and flavonols between the cryo- and in vitro-derived plants. Analyses of ISSR and AFLP markers did not detect any polymorphic bands in the cryo-derived plants. These results indicate rooting and vegetative growth ability, biochemical compounds and genetic stability were maintained in cryo-derived plants. The present study provides experimental evidences that support the use of cryopreservation method for long-term preservation of genetic resources of shallots and other Allium species.