Somatic embryogenesis and plantlet regeneration on calluses derived from seedling explants of ‘Kinnow’ mandarin (<i>Citrus nobilis</i>Lour, ×<i>Citrus deliciosa</i>Tenora)

Abstract

SummaryCallus cultures of ‘Kinnow’ mandarin (Citrus nobilis Lour, × Citrus deliciosa Tenora) were established from a range of different somatic explants excised from three week old in vitro-grown nucellar seedlings. The explants tested included leaf, epicotyl, cotyledon and root segments. All cultured explants initiated callus from the cut ends after a week, when cultured on a modified Murashige and Tucker (1969) medium; cotyledon segments were the best explant for callus induction. The calli derived from epicotyl segments were also the best source of somatic embryos. Embryogenic calluses were subcultured on MS medium fortified with BAP (3 mg l−1) +NAA (0.5 mg l−1) + malt extract (500 mg l−1) showed further growth, development, budding and germination of somatic embryos. Root initiation took 7−10 d after culturing on various rooting media. The number of roots per shoot varied from 1−2 to 6−8 on MS medium containing NAA and/or IBA. Plantlet survival in vitro was directly related to the number of roots produced per shoot.