Ex vitro rooting of minicutting of Carica papaya L. single shoot from tissue culture

Papaya ( Carica papaya L.) is an important economic crop. An efficient and low-cost propagation ex vitro process is required for commercial papaya plantlet production. In this study, a propagation process of papaya was established by minicutting and evaluating parameters affecting survival. Individual shoots (1.5 cm) were cut from papaya multiple shoots in vitro as the minicuttings. After dipping in 400.0 mg L −1 indole-3-butyric acid (IBA), they were planted into the nursery pro trays with 104 holes containing vermiculite, perlite, and King Root® substrate at 1:1:1 ratio, and then covered with a lid to keep the ratio of humidity (RH) at 100% for root development. After a 3-wk treatment in a growth chamber (28°C), the rooting rate, root number, root length, and stem length were promoted to 91.1%, 2.9, 3.71 cm, and 1.88 cm, respectively. Combining the treatment with 400 mg L −1 IBA and 1/2 Murashige and Skoog (MS) salt solution supplemented at the 14th day after cutting gives the best growth potential for papaya plantlets, especially increasing root length to 4.55 cm. It also effectively enhances the survival rate of plantlets to 93.3%. This process saves the rooting initiation medium and time cost and avoids the complicated procedure of cleaning medium from root surface, which results in root damage. Under this minicutting process, the papaya plantlets thrived and were optimally suited to field cultivation.