A Two Step Process for the Regeneration of Arachis spp. by Shoot Tip Culture of Greenhouse-Grown Plants

Shoot-tips of peanut (Arachis hypogaea L.) cultivars Florunner and Pronto grown in the greenhouse, and the tips of A. villosulicarpa Hoehne from in vitro cultured plants were used for in vitro regeneration of peanut. The terminal and lateral buds excised from greenhouse grown plants were surface sterilized with 70% ethanol for 3 min followed by 0.525% sodium hypochlorite for 5 min. Shoot-tips (0.5–3 mm long) were isolated from the buds, transferred to a modified Murashige Skoog (MS) agar medium, and maintained at 26 C with a 16-h photoperiod. The modified MS medium contained MS mineral salts, B5 vitamins, and the hormones 1-naphthaleneacetic acid (NAA) and 6-benzyladenine (BA). The best growth of meristems (0.5–1 mm) was induced with 5.0 μM NAA and 5.0 μM BA. Rooting was induced with 5.0 μM NAA. Both shoot growth and rooting occurred on medium that contained 5.0 μM NAA when large tips (1–3 mm) were cultured. Plantlets regenerated from the tips were successfully transferred to pots and grown to maturity.