Phenotypic and molecular studies for genetic stability assessment of cryopreserved banana meristems derived from field and in vitro explant sources

Explants used for cryopreservation of banana ( Musa L. spp.) are mainly sourced from tissue culture. Here, we demonstrate the successful use of sucker meristems (SM) obtained from field-raised plants for cryopreservation of Indian Musa ABB cv. ‘Karpura Chakkarakeli’. In addition, the genetic stability of plants recovered from cryopreserved and regenerated meristems after hardening and transfer to field conditions was studied using 11 phenotypic (biometric) characters and 21 simple sequence repeat (SSR) markers. The regenerative potential of cryopreserved SM was compared with two types of routinely employed explants of banana germplasm: in vitro -raised single-shoot meristems (IVM) and proliferating meristems (PM). The regeneration frequency of SM was high (60.0 ± 11.5%) and statistically comparable to PM (68.3 ± 4.4%) and IVM (55.6 ± 11.1%) after using the droplet vitrification cryopreservation technique. The total time required for cryopreserving plants from SM (∼2 mo) was substantially less than that for PM (14 mo) and IVM (8 mo). The SSR profiles of plants recovered from cryopreserved PM, IVM, and SM and compared with control plants had a similarity coefficient of 0.92. Data on phenotypic traits revealed that cryopreserved plants were statistically comparable to the mother plants raised from suckers for all important growth and yield parameters. This study broadens the possibilities to cryopreserve Musa germplasm, by applying the droplet vitrification method to a new type of explant, the SM. The results presented in this paper show that Musa meristems can be effectively cryopreserved for storage and regeneration of true-to-type plants.