Use of Jasmonate for conditioning of potato plantlets and microtubers in greenhouse production of minitubers

A two-year study was conducted to determine the effects of (1) jasmonic acid (JA) pre-treatment, (2) JA supplement in culture media, (3) cultivar (Amisk, Atlantic, Russet Burbank, Shepody, and Umatilla Russet), (4) fight (0 h, 8 h), and (5) dormancy breaking treatment (Rindite, gibberellic acid) on greenhouse production of minitubers from microtubers and in vitro plantlets. The microtubers were produced under short day (8 h) fight conditions and in darkness, from stock plantlets pre-treated with JA and untreated, and on tuberization media with or without JA. In vitro plantlets (the industry choice in nuclear seed potato production) of all five cultivars performed well, meeting the standard criteria for greenhouse production of minitubers. Production of minitubers from microtuber-derived plants of cvs Amisk, Russet Burbank, and Umatilla Russet was similar to that of plantlet-derived plants with regard to number of minitubers. Yields (weight), however, were lower than those from plantlets. Microtuber responses to JA varied with cultivar. Amisk produced the highest number of minitubers per plot from microtubers derived from JA pre-treated plantlets. Jasmonic acid-pretreated microtubers also gave significantly more minitubers in Russet Burbank and Umatilla Russet than the microtubers from other treatments. Shepody did not benefit from JA treatments and JA pre-treated Atlantic microtubers performed poorly, producing significantly lower yields of minitubers than other cultivars. Independently of cultivar, microtubers produced under 8-h photoperiod gave significantly higher yields of minitubers than microtubers produced in the dark. Dormancy release was the key factor influencing microtuber performance. Rindite proved to be a much more effective dormancy breaking treatment than gibberellin. JA conditioning of stock plants prior to tuberization is being proposed as a treatment in production of microtubers for greenhouse production of minitubers.