Fruits from the winter season crop of guava (Psidlum guajava L.) were harvested at the green mature stage and stored at ambient conditions in three postures: 1) natural, pedicel end vertically upward; 2) reverse, pedicel end vertically downward; and 3) horizontal, pedicel end sideways. Fruits in the natural posture showed minimum physiological loss in weight, ripening percentage, ethylene and CO2 evolution rates, and maximum soluble solids and ascorbic acid concentrations during storage. Organoleptic rating and other characteristics indicate that guava fruits should be packed in the natural posture to retain better quality for longer periods.
An efficient protocol has been established for generating somaclones in the Indian rose-scented geranium Pelargonium graveolens cv. Bipuli, which yields Reunion Island-type essential oil. Murashige and Skoog's (MS) medium supplemented with 4.5 mg·L-1 BA and 1.0 mg·L-1 NAA was found optimal for induction of callus from leaf explants. Callus regenerated shoots when transferred to MS medium with 2.5 mg·L-1 BA and 0.1 mg·L-1 NAA. The regeneration percentage as well as number of shoots per cm2 of callus was greatly improved by addition of ADS at a concentration of 3.0 mg·L-1. Regenerated shoots rooted within 20 days following transfer to half-strength MS medium with 0.1 mg·L-1 NAA. Plantlets were acclimatized under glasshouse conditions with 80% to 85% survival. Randomly selected 30 individual calliclones were subjected to field trial with wild-type parent in randomized block design, replicated three times with 90% survival for two successive years. Characterization of these calliclones for essential oil yield and quality traits demonstrated induction of variability in all the characteristics examined in negative and positive directions in comparison with the wild-type parent. This screening led to the identification of somaclone B22, which out-yielded the wild-type parent as well as the rest of the somaclones. The quality of the essential oil of B22 was similar to that of the parent. Chemical names used: N6-benzyladenine (BA); naphthalene acetic acid (NAA); adenine di-sulphate (ADS).