Materials and Methods
2.1. Explant Material
Seed material of guava cultivar “Lucknow 49” was obtained from a seven year old tree growing in a greenhouse.
Seeds were surface sterilized in 70% ethanol for 1 min, washed in 10% (v/v) commercial bleach solution for 15
min and then rinsed three times, 5 min each, in sterile distilled water. Seeds were then germinated on MS medium
[17] supplemented with 3% sucrose, 2.5 g∙L−1phytagel, 1.0 ml∙L−1 plant preservation mixture (Plant Cell
Technology, Inc., Washington DC) and 0.4 μM 6-benzylaminopurine (BA). Test tubes were incubated in the
dark at 25˚C ± 2˚C for three weeks following which the seedlings were maintained under a 16 h photoperiod (50
μmol∙m−2∙s−1) for 5 - 6 weeks. Two nodal explants from a single seedling were transferred to MS medium supplemented
with 8.8 μM BA and 9.3 μM kinetin (KIN) for shoot proliferation. Cultures were maintained as described
previously [18]. After shoot establishment, explants were grown in G7 Magenta boxes (Magenta Corporation,
Chicago, IL, USA.) containing 50 ml MS medium for two weeks prior to root induction.