SATURATED CARBOXYLIC ACID-INDUCED IN VITRO TUBERIZATION IN POTATO (SOLANUM TUBEROSUM L.)

Abstract

Two saturated carboxylic acids, viz., formic and acetic acids (0.0, 1.5, 3.0, 4.5 and 6.0 mM) were added to microtuber induction medium (MS medium plus 80 gl-1 sucrose), and their role in microtuberization was studied using single node cuttings under continuous darkness at 20 °C in three potato (Solanum tuberosum L.) genotypes. Both the carboxylic acids induced early tuberization compared to control induction medium containing only 80 gl-1 sucrose. Although formic acid did not have any promoting effect on microtuber number, acetic acid significantly increased the microtuber number in cvs Kufri Badshah and Kufri Jawahar. However, both the carboxylic acids had a detrimental effect on average microtuber fresh weight, and this inhibitory effect on microtuber development progressively attenuated with their increasing concentrations. In general, they increased the percentage of microtuber dry matter. Acetic acid was more effective than formic acid in enhancing the dry matter; about 5-6 % increase in dry matter, compared to control induction medium, occurred in microtubers when they were induced in medium supplemented with 4.5-6.0 mM acetic acid. The results showed that saturated carboxylic acids had a mode of action on potato microtuberization identical to that of antigibberellin agents. High dry matter in microtubers induced by carboxylic acids, especially acetic acid, may improve the quality of microtubers in terms of storage, dormancy breaking and sprout emergence.