Micropropagation of mature male pistachio Pistacia vera L.

Factors affecting the successful rapid proliferation and rooting of male pistachio (Pistacia vera L.) cv. Ath, were studied. The most suitable type of cytokinin [6 benzyladenine (BA), kinetin (Kin), or thidiazuron (TDZ)], and the effect of eight different concentrations of BA (0.0675, 0.125, 0.25, 0.5, 1.0, 2.0, 4.0, or 8.0 mg l(-1)) were evaluated to optimise shoot proliferation. The auxins alpha-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA), and indole-3-butyric acid (IBA), each at 2.0 mg l(-1), or different concentrations (0.5, 1.0, 2.0, 4.0, or 8.0 mg l(-1)) of IBA, and the effect of explant size (1.0, 2.0, 3.0, or 4.0 cm) were assessed for root induction. The highest number of new microshoots per explant (5.64 +/- 0.07) was obtained 4 weeks after culturing on Murashige and Skoog (MS) medium supplemented with 1.0 mg l(-1) BA. Again, shoot length was highest in 1.0 mg l(-1) BA, and decreased as the BA concentration increased. IBA was most effective in promoting root formation. The highest rooting frequency (73%) of microshoots was recorded for explants 4.0 cm in length, 4 weeks after culturing. In vitro-rooted plantlets were transferred to polyethylene pots filled with a 1:1:1 (v/v/v) mixture of soil, sand and peat. This treatment resulted in 90% survival of plantlets, which were acclimatised in a greenhouse.