The embryogenic capacities of flower explants from one- and two-week-old male inflorescence buds from Musa acuminata Cavendish, AAA, genotypes ‘Williams’ and ‘Grand Naine’ were investigated. Explants of hands with immature flowers were excised and induced for embryogenesis. Highly significant differences were found in the embryogenic response, depending on the genotype and the developmental stage of the buds from which the explants were excised. After four months of induction, the total percentage of callus formed ranged from 97.81% in explants of two-week-old ‘Williams’ buds to 52.11% in explants of two-week-old ‘Grand Naine’ buds. Embryogenic callus formation was, on average, higher in the two-week-old ‘Williams’ explants (10.01%) than in the one-week-old explants (0.78%). The opposite was true for ‘Grand Naine’, with 7.51% embryogenic callus produced in explants of one-week-old buds compared to 2.49% in two-week-old buds. Selected embryogenic calluses that were successfully established on proliferation medium led to embryogenic cell suspensions with good regeneration capacities. Fifteen to thirty-five percent of the embryos germinated, demonstrated high plant-conversion capacity (99%). The effect of the interaction between the developmental age of explant and the genotype on the embryogenesis response is discussed.

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.

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.