Production and cryoconservation of embryogenic cultures of mandarin and mandarin hybrids

Assays were performed to obtain embryogenic callus lines from nine mandarin and mandarin hybrid cultivars by in vitro culture of ovules collected from immature fruits six weeks after anthesis. All cultivars produced embryos a nd loose friable callus. The small proliferations of nucellar callus from c ultured ovules were suitable to recover embryogenic callus lines by periodi cal subculturing to fresh medium. The embryogenic callus cultures were subj ected to cryoprotection with 10% (v/v) (DMSO), freezing by slow cooling, st orage in liquid nitrogen and thawing by fast warming. Whole plants from the se cryopreserved cultures were recovered through embryogenesis.