In vitro plant regeneration of Artocarpus heterophyllus Lam. using shoot tips of mature trees

Abstract

Abstract Jackfruit (Artocarpus heterophyllus Lam.) belonging to the family Moraceae is the largest fruit in the world. Jackfruit is a cross-pollinated species exhibiting wide genetic variation resulting in heterozygosis and degradation of the quality of seedlings. Additionally, due to the recalcitrant nature of the jackfruit seed, its storage, even for a short time, results in loss of viability and poor germination. Hence, propagation of the jackfruit plant from seeds is not recommended for commercial cultivation. Traditional ex vitro vegetative propagation methods such as budding, grafting, and cutting, show a slow growth rate, and the process is cumbersome and time consuming. To overcome these challenges and to produce true-to-type jackfruit plants for quality maintenance and sustenance, in vitro propagation using shoot tips from mature jackfruit trees was undertaken. The actively growing shoot tips from mature jackfruit trees were excised, washed, and sterilized with 70% ethanol and 0.1% HgCl2. This was followed by inoculating the explants on MS medium supplemented with various combinations of plant growth regulators to induce shoot proliferation and subsequent rooting. In the present study, the highest rate of shoot initiation (93.33%) with the highest number of shoots (5.93) per shoot explant was achieved on MS medium fortified with 3.0 mg/L BAP and 2.0 mg/L TDZ. The excised microshoots rooted on half-strength MS medium with 2.0 mg/L IBA induced the highest number of roots (8.07) per shoot. The in vitro obtained jackfruit plantlets were acclimatized the best in vermicompost-containing potted plants with a 95% survival rate. The gradually acclimatized jackfruit plants were further transferred to natural conditions, where 90% of the plants survived successfully.