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 mu M 6-benzyladinine. Leaf explants were cultivated in the presenc e of the same growth regulator at 22 mu M. Cultures were incubated at tempe ratures of 25, 28, and 35 +/- 5 degrees C. Both direct organogenesis from c otyledons and development of organogenic calluses from leaves showed optima l rates at 35 +/- 5 degrees C. The highest frequency of elongation of buds into, shoots formed ed calluses occurred in the presence of 5 mu M AgNO3. A t the Lest culture temperature. an average of 95% of shoots formed roots on growth-regulator-free MS medium. Plants were successfully transferred to s oil, showing normal phenotypes.