Abstract

Mungbean [Vigna radiata L. (Wilczek)] is a valuable legume crop in Bangladesh. However, it faces severe difficulties forming viable roots during the growth stage. The successful root production of mungbean through an efficient tissue culture system has not been well established. Therefore, this study aims to investigate the problem of unsuccessful root formation in mungbean plants and to develop a very efficient method of in vitro regeneration using micropropagation. The BARI Mung-3 mungbean variety was used as an explant. Several shoots were produced from cotyledonary node (CN) explants obtained from 3-day-old seedlings that were germinated in vitro. The plant samples were cultivated on MSB5 medium enriched with 5.0 μM BAP. Shoot generation efficiency per plant was 5.36 ± 0.56 (80.08%). However, the viable root generation in a regulated setting was unsuccessful despite employing multiple combinations of rooting media, including full and half-strength MSB5 medium with different concentrations and combinations of auxins. To resolve this issue, a micrografting approach was applied with scion 3.0 cm in length and 14-day-old mungbean rootstocks. This system resulted in efficient shoots where the viable root generation efficiency rate was 55%. Interestingly, the micro-grafted plantlets successfully produced viable seeds. The successful micropropagation with viable root generation in mungbean plants successfully overcomes the difficulties in rooting and offers an efficient method for successful mungbean production. These new findings open new options for efficient plant generation with mass propagation for ready-smart mungbean production.

Key words: Legumes, In vitro shoot regeneration, Micrografting, Cotyledonary node, Rooting.