STIMULATORY EFFECTS OF JASMONIC ACID ON POTATO STEM NODE AND PROTOPLAST CULTURE

The effect of jasmonic acid (JA), in a wide range of concentrations (0.01-100-mu-M), on the development of potato plantlets (Solanum tuberosum L.cv. Vesna) was investigated in order to discriminate between physiological and supraoptimal effects of this growth regulator in vitro. Concentrations from 0.1-1-mu-M significantly increased the length of developed plants. Application of JA in these concentrations resulted in a very well differentiated root system with many lateral branches. With increasing JA concentrations, the main roots shortened and thickened. Concentrations higher than 10-mu-M led to the compaction of the stem, roots, and root hairs, giving a stunted appearance to the plants. The effect of JA on cell wall regeneration and callus formation was observed in potato leaf protoplast culture. JA at concentrations from 0.01-1-mu-M stimulated cell division and microcalli development.