بهبود ريشه زايي و سازگاري گياهچه هاي كشت بافتي زيتون زرد با استفاده از باكتري Agrobacterium rhizogenes و قارچ Trichoderma harzianum

Improvement of Rooting and Aclimatization of Tissue Cultured Plantlets of Olive (Olea europaea L. cv. Zard) by Agrobacterium rhizogenes and Trichoderma harzianum

To improve rooting of micro cutting produced in shoot proliferation stage of an Iranian native olive cultivar, Zard, with the aim of developing a commercial micro-propagation protocol, by using Agrobacterium rhizogenes and Trichoderma harzianum this research was carried out. Effect of A. rhizogenes was evaluated on rooting percentage, amount of callus formation at the base of micro cutting and plantlet growth quality index, 2 and 4 weeks after culture. Results showed that inoculation of micro shoots with bacterium in association with 1.0 mg/I IB A in the culture medium had significant effect on rooting percentage and reducing the amount of callus formation. The highest rooting (70%) was obtained in inoculated treatment 4 weeks after culture while only 30% rooting was observed in control treatment. Regarding callus formation, the lowest amount (46.6%o) was produced in bacterial inoculated as compared to 100%) in the control treatment. Root induction at the base of micro-shoots without or with less callus formation is an advantage during transferring to in vivo conditions and acclimatization. It was revealed that inoculation with A. rhizogenes greatly increased rooting, reduced callus formation considerably as compared to control. In acclimatization stage, infected roots of plantlet with T. harzianum showed increases in number of roots produced on each plant (11.8) and root length (215.3 mm) as compared with control (2.7 and 60 mm respectively). Therefore, due to the stimulating effects, this fungus can be used for root initiation and development at the early stages of growth and acclimatization of olive micro-propagated plantlets.