In vitro regeneration of peanut (Arachis hypogaea L.) through organogenesis: Effect of culture temperature and silver nitrate

The effect of culture temperature on the morphogenetic response of Arachis hypogaea was studied. Cotyledons were cultivated on MS medium supplemented with 110 μM 6-benzyladenine. Leaf explants were cultivated in the presence of the same growth regulator at 22 μM. Cultures were incubated at temperatures of 25, 28, and 35 ± 5°C. Both direct organogenesis from cotyledons and development of organogenic calluses from leaves showed optimal rates at 35 ± 5°C. The highest frequency of elongation of buds into shoots from leaf-derived calluses occurred in the presence of 5 μM AgNO3. At the best culture temperature, an average of 95% of shoots formed roots on growth-regulator-free MS medium. Plants were successfully transferred to soil, showing normal phenotypes.