Involvement of jasmonic acid and light periods on potato microtuber growth response

The present study was conducted to determine the effects of Jasmonic acid (JA) and light periods on performance of microtuber growth response in five potato cultivars (Diamant, Atlanta, All Blue, Shepody and Shilbilaty). Microtubers were produced from in vitro grown plantlets treated with or without 5µM JA on micropropagation and microtuberization media under 0 and 8 h light periods. Microtuberization was established in MS liquid media having 8% sucrose along with the above treatments. Among the investigated cultivars, the highest number of microtubers (12.97 microtubers per vessel) was obtained in All Blue. On the other hand, Diamant microtubers gave maximum fresh weight (106.7 mg) and Shilbilaty yielded the highest percentage (57.72%) and number of larger microtubers (8.25 larger microtubers out of total 12.78 microtubers per vessel) followed by Diamant and All Blue. Atlanta showed lower values at all investigated microtuber growth traits. Microtuber growth was better in 5µM JA supplemented microtuberization media with 8 h photoperiodic incubation than those were in micropropagation media with the same treatment. The 0 h period was found significantly inferior than 8 h at all growth traits.