Influence of zeatin, glutamin and auxins on root and shoot organogenesis of Guava (Psidium guajava L.) cv. safeda seedling explants

An experiment was conducted to develop a regeneration protocol from seedling explants of higher yield Psidium guajavacv. safeda. Initially surface sterilized guava seeds were germinated inside the conical flasks. Explants taken from 49-day old seedlings were cultured on MS-medium modified with different concentration of plant growth regulators. Maximum explants showing shoot response (48%) was observed on MS-medium supplemented with 6-benzyladanin (BA) 1.0 mgl-1combined with 0.5 mgl-1ziatin. On the same media after 38-days of culturing, maximum number of 3.6 shoots per explant, 2.6 cm long was also recorded. On MS containing combination of BA (2.0 mgl-1) and zeatin (1.0 mgl-1), 37% explants responded which produced 2.3 shoot per explant after 42 days of culturing. Whereas on MS containing glutamin 250 mgl-1, 25% explants responded and gave 2.2 shoots per explants after 46-days. However, when the concentration of glutamin alone was increased from 250 to 500 mgl-1 the shoot formation potential of explant decreased to 10%. Addition of BA, glutamin and zeatin alone to MS medium was less effective. However, combination of BA with zeatin was effective in shooting response, number of shoot/explants and shoot length. Maximum number of explants (76.6%) responded to rooting with 1.5 mgl-1 IAA in combination with 1.0 mgl-1 NAA. On average, maximum of (2.5) roots were also recorded per explants in 42 days. In vitro plantlets were acclimatized and shifted to soil successfully. Keywords: Psidium guajava L; Micropropagation; Zeatin; Glutamin and auxins http://dx.doi.org/10.19045/bspab.2017.60014