Effect of boron and jasmonic acid on in vitro production of potato microtubers

الملخص EN

The present study was conducted in Tissue Culture Laboratory of Agric.

Bot.

Department, Fac.

Agric, Ain Shams Univ., during the period from March 2005 to May 2007 to study the effect of jasmonic acid (JA) at 10"6, 10-5 and 10"4 M and Boron (B) at 9.1 and 12.4 mg/1 and their combinations on in vitro tuberization of two potato cultivars; Spunta and Diamont.

Single node cuttings were used for microtuber production using MS medium supplemented with 0.7 % agar, 80 g/1 sucrose and kinetin at 2 mg/1 and was incubated in dark at 15° C.

Control medium was free from JA and contained the basic concentration of B (6.2 mg/1 boric acid) in Murashige and Skoog (MS) medium.

Application of B to the medium greatly affected microtubers induction and growth.

The additional B in the medium showed an increase in microtubers number, fresh and dry weights, percentage of microtuberized explants and microtubers size.

These effects were directly proportion with the concentration.

Adversely, JA showed significant reduction in the previously mentioned parameters at 10"6, 10"5 M and at 10"4 suppressed microtubers induction completely.

Boron treatment showed an increase in total soluble carbohydrates and plant growth promoters IAA, GA3 and zeatin concentrations and reduced ABA in the resultant microtubers.

The opposite trend was true with JA treatments.

The presence of B with J A at 10"6 and 10"5 M in the medium reduced the harmful effect of JA on the developed microtubers especially when the low concentration of J A (10"6 M) was accompaned with the high concentration of B (12.4 mg/1).

The effects of B and JA on microtubers induction and development, as well as, the correlated changes in total soluble carbohydrates and endogenous phytohormones were discussed.

Key words: Tissue culture, Potato, Solarium tuberosum L., Tuberization induction, Microtubers, Jasmonic acid, Boron.