An approach towards induction of double haploids in okra (Abelmoschus esculentus L. Moench)

Abstract

Okra (Abelmoschus esculentus L. Moench), also known as “lady’s finger”, belonging to the Malvaceae family, is an alloploid. Availability of haploids and doubled haploid lines are essential for the development of improved okra hybrid varieties. Anthers were excised from flower buds at different stages. The ability to produce haploid callus or somatic embryogenesis and thereby, regenerate into haploid plants was investigated. Several factors, such as flower bud initiation time, type of media and plant growth regulator combinations have been evaluated. The flower buds of different sizes were dissected to determine stages of development before subjecting to various pre-treatments and then the anthers. These were cultured on different PGR combinations (NAA, IAA, 2,4-D, KIN, BAP, IBA, ZTN, 2iP, GA3 and TDZ) and various concentrations. The cultures were incubated in both dark and light conditions. The suitable developmental stage of microspore for callus induction was obtained from 12 mm length of flower buds in okra for calli and root development. The effect of flower bud initiation time was an important factor in anther cultures. The media, MSNB, gave highest percentage (95 %) of callus induction. Incubation for 28 days in dark gave highest percentage (92.5 %) of callus induction. The ultimate aim of this study was to investigate the potential of okra anther culture. The study will ultimately help in double haploid development for faster crop improvement.