Improvement of Psidium guajava']java L. Using Micropropagation

Here we describe an innovative, reproducible, and inexpensive method for in vitro cloning of guava using nodal stems segments. A novel process was established for completely inhibiting phenol-based browning by coating the explants at their cut ends with commercial silicon. A high regeneration frequency (98.33%) was achieved on MS medium supplemented with 4 mg/L BA and 0.4 mg/L IAA, with a maximum average number of 76.17 shoots per explant produced on the third subculture. The highest rooting percentage (95.83%) was obtained on shoots growing on half strength MS medium and supplemented with 4 mg/L IAA. The plantlets were acclimatized and successfully established in soil. RAPD analysis was used to compare the regenerated plants with their donor parents: the analysis showed a high similarity (94.50% on average) among the regenerated plants and their donor parents. Taking advantage of such highly regenerative technique in a woody plant like guava, an exponential increase in the number of in vitro produced plantlets can be achieved by utilizing the resulting shoots as nodal explant starting material to commercially propagate guava in vitro.