In vitro PROPAGATION OF GUAVA SELECTIONS (Psidium guajava']java L.)

In vitro propagation of guava (Psidium guajava L.) shoots by direct organogenesis is an alternative to quickly obtain productive plants. This work optimized a protocol for in vitro regeneration from apexes and nodal segments of five different guava genotypes with high commercial potential Paluma 12 (PM12), Paluma 6 (PM6), 17-06, Roja Exterior Redonda (RER) and Roja Chapeada Grande (CHRG). The effect of polyvinylpyrrolidone (PPVP) was evaluated as an antioxidant. Genotypes RER and CHRG showed low phenolization problems of 10 y 0 %, respectively. In the multiplication phase, genotypes PM6 and PM12 showed the best results when their shoots were grown on Murashige y Skoog medium (MS) supplemented with 0.5 mg L-1 BAP and 30 mg L-1 adenine; meanwhile var. 17-06 developed better by addition of 15 mg L-1 of adenine sulfate. Addition of 40 mg L-1 of adenine sulfate resulted in the best treatment for vars. RER and CHRG. Rooting was induced by 24 h of shoot incubation on MS medium supplemented with 2.54 mg L-1 IAA for var. 17-06, while IBA at 1.34 mg L-1 induced rooting in cvs. PM6 and RER; IBA concentration had to be increased to 2.94 mg L-1 for better rooting in var. CHRG and PM12.