Multiple shoot regeneration from excised embryonic axis explants of jute, Corchorus capsularis cv. JRC321

Abstract

Interspecific hybrids development by traditional breeding is challenging because of the incompatibility between two cultivated species of genus Corchorus. Under this condition, plant genetic transformation is an alternative tool for the improvement of jute cultivar. In the present study, in vitro multiple shoot regeneration protocol has been developed in jute (Corchorus capsularis cv. JRC 321) from excised embryonic axis as an explants by removing cotyledons, radicle, and tip of epicotyl. The explant is cultured in medium shoot multiplication medium1 (SMM1) supplemented with BAP (1.0 mg/L) for one week and sub-cultured in SMM6 containing IBA (0.5 mg/L) and BAP (0.2 mg/L). Direct adventitious shoot bud formation was observed from cotyledonary nodes and the adjacent region of excised embryonic axis. Interestingly, shoot bud formation was reduced when excised explants with intact epicotyl were cultured in the media combination (SMM1+SMM6) indicating the presence of apical dominance might be the cause of fewer shoot bud formation. While, hypocotyl explants did not produce any shoot in this media combination because nodal meristem was removed. However, the shoot buds developed from the excised embryonic axis were differentiated successfully into multiple shoots and showed further elongation in SMM6 which ultimately rooted in MS-B5 medium (+ 0.5 mg/L IBA). The plants were transferred successfully in the glasshouse conditions and appeared phenotypically normal.