Establishment of tissue culture protocol of Brassica Juncea var. BARI Sarisha-11

Abstract

Brassica sp., commonly known as mustard, holds significant economic importance as a crop with high oil content, particularly in Bangladesh. Despite widespread demand, obstacles in production such as insufficient germination and various biotic and abiotic factors persist, biotechnological methods, including tissue culture, gene transfer, and genome editing systems, are increasingly employed to enhance this crop quality. This study focuses on improving Brassica juncea, specifically the variety BARI Sarisha-11, a vital mustard variety in Bangladesh. The primary objective is to refine a tissue culture-mediated regeneration procedure, laying the groundwork for future applications in micropropagation. In this study, to achieve high-frequency, uncontaminated germination, a seed sterilization protocol was established. Various combinations and durations of 70% ethanol, 0.1% mercury chloride, and 10% Clorox solution were tested. Among them, the highest optimal uncontaminated germination was obtained when seeds were sterilized with 70% ethanol for one minute and 0.1% mercury chloride for ten minutes. For shoot regeneration, 7 days old- cotyledonary leaves with petiole explants were used in nutrient media enriched with plant growth regulators, specifically 6-benzylaminopurine (BAP), 6-furfurylaminopurine (Kinetin/Kn), and naphthalene acetic acid (NAA). The highest regeneration (75%) was achieved with 1.0 mg/L BAP, 0.1 mg/L NAA, and 0.5 mg/L Kn. Rooting was examined using hormone less half-strength MS media, and acclimatization of plantlets was done in sterilized potted soil. Only one plantlet was produced following transplantation. In summary, given the crucial role of mustard as the primary oilseed crop in Bangladesh, this study represents a vital initial step in implementing mustard crop improvement techniques. The establishment of a practical, efficient, and replicable regeneration process, as demonstrated in this study, holds significant importance for the future of mustard cultivation.