Improved Shoot-tip Micropropagation of Pistacia Vera L. and the Beneficial Effects of Methyl Jasmonate

Abstract

Micropropagation of Pistacia vera `Mateur' was improved by adding MeJA to the multiplication and rooting media. Shoot-tip cultures established from grafted trees were maintained on a modified Murashige and Skoog medium containing 5 μm BA and 0.05 μm IBA. Adding 0.3, 1, or 3.2 μm MeJA improved shoot multiplication rates 2.5, 3.0, and 2.3, respectively. There was a significant interaction between the effects of auxin and temperature on the percentage of shoots forming roots. At 25C, the percentage of shoots forming roots was higher in the presence of NAA than IAA or IBA, whereas, at 28C, there was no difference among the auxins. Adding MeJA to the best auxin treatments-31.6 μm NAA at 25C and 31.6 μm IAA at 28C-increased the percentage of shoots forming roots and number of roots per shoot but decreased root length. More than 80% of the shoots rooted at 25C when 1 μM MeJA was added to the root induction medium, which contained 31.6 μm NAA, and the root elongation medium, without auxin. The large number of short roots induced by MeJA facilitated plantlet transfer to soil and acclimation. Chemical names used: methyl jasmonate (MeJA); N6-benzyladenine (BA), indole-3-butyric acid (IBA), α-naphthaleneacetic acid (NAA), indole3-acetic acid (IAA).