A COMPREHENSIVE DESCRIPTION OF EX-VITRO ROOTING OF PISTACHIO ROOTSTOCKS GROWN IN PHOTOMIXOTROPHIC AND PHOTOAUTOTROPHIC CONDITION

As a basic principle, ex-vitro rhizogenesis increases the micropropagation efficiency of Micro propagation in any plant from both biological and economic viewpoints. In the current study, we surveyed the effects of number of air exchanges along with sucrose concentration on in-vitro rooting of two pistachio rootstocks consisting of UCB1 and Qazvini versus ex-vitro rooting. Based on our findings for the UCB1 rootstock, microshoot ex-vitro rooting reached the highest percentage (63.70 %) after six weeks' treatment with indole butyric acid (IBA) (5000 ppm) and free naphthalene acetic acid (NAA), while for Qazvini rootstock treated with NAA (6000 ppm) along with IBA (5000 ppm), rooting achieved 35.06%. Photomixotrophic resulted from decreasing sucrose concentration from 30 to 15 (g L-1) in corporation with ventilation condition increased UCB1 rooting (67.89%) as well as plant survival (58.34%). For Qazvini rootstock, maximum sucrose concentration (30 g L-1) improved rooting parameters. For in-vitro rooting experiment, rooting percentage of UCB1 plantlets as well as the main and lateral produced roots were higher in media supplemented with (1 mg l-1) IBA, free NAA, and BA. Regarding Qazvini rootstock, the highest in-vitro rooting percentage (43.75%) and root length were associated with the media supplemented with BA (0.5 mg l-1), IBA (2 mg l-1), and NAA (2 mg l-1). As a result, for both the studied rootstocks, better rooting parameters were observed in the ex-vitro rooted microshoots than in-vitro rooted.

Growth performance of Hydrangea macrophylla ‘glowing embers’ on culture medium with different macro-element concentrations and culture conditions

Hydrangeas are very popular shrubs thanks to their attractive, colorful flowers and foliage. Recently, they have been commercialized for cut-flower production. For mass propagation of this plant species using plant tissue culture, it is necessary to study the effects of culture medium and culture conditions on in vitro plant growth. In the first experiment, in vitro hydrangea shoots were cultured for 56 days on Murashige and Skoog (MS) media containing one among five different types of macro-elements. The half concentration of NH4NO3 on MS macro-elements significantly increased fresh and dry weights of hydrangea shoots in comparison with other treatments. The number of roots of in vitro plants in this treatment were the highest, resulting in better absorption of culture nutrient. Cross sections of the shoot base on day 14th showed that reducing only NH4NO3 on the MS medium enhanced the formation of adventitious roots. The experiment on culture conditions showed that photoautotrophic condition was suitable for the in vitro growth of hydrangea. Plants grown under photoautotrophic (PA) condition had increased fresh weight (341.39 mg/plt), increased dry weight (31.03 mg/plt) with leaf area (7.76 cm2) significantly greater than those grown under photomixotrophic (PM) condition (259.53 mg/plt, 38.22 mg/plt and 4.73 cm2 respectively). In addition, the net photosynthetic rate (Pn) of plants under PA condition was statistically higher and increased over the culture period while Pn of plants under PM condition remained constant. This study demonstrated that MS salts with half concentration of NH4NO3 and photoautotrophic culture method were appropriate for in vitro growth of hydrangea.