Embryo culture and embryo rescue studies in wild Musa spp. (Musa ornata)

Abstract: Seed set in Musa spp. is known to vary greatly among seed-fertile cultivars, but germinate at an intractably low rate in soil thus making breeding of plantains and bananas difficult. Hence, there is an increased interest in in vitro germination of both intact seeds and excised zygotic embryos. The present work deals with the influence of maturity and hormonal factors on germination and regeneration of Musa ornata seeds through embryo culture and embryo rescue. Embryos extracted from seeds harvested at various maturity stages were cultured in MS media with different concentrations of plant growth regulators. Good embryo recovery was seen in seeds from 80 and 100% mature fruits. Maturity status of embryos played a key role in direct and indirect regeneration. Medium rich in auxins led to callus (M₈) formation at all maturity levels, leading to indirect regeneration. Good direct regeneration was observed from 100% mature embryos, in media supplemented with 6-benzylaminopurine (M₄). Study revealed that zygotic embryos of M. ornata could be rescued and regenerated through callus when harvested at 80% maturity and media augmented with Kinetin (M6) gave the best regeneration. In general, medium rich in auxins led to callus formation at all maturity levels. Therefore, in vitro embryo culture and embryo rescue provide a potential tool for recovery and perpetuation of wild Musa species.