Establishment and Micropropagation of Iranian Quince Cultivars for Using in Breeding Programs

Quince is among the most sensitive hosts of fire blight cause (Erwinia amylovora) and it would be necessary to consider some strategies for reducing the damage of the disease to this valuable horticultural species. In this research project in order to use some biotechnology tools for quince breeding, in vitro establishment and primary propagation of several quince cultivars were investigated. In the initial phase, culture medium and plant growth regulators were optimized for culture establishment shoot proliferation and rooting stages of some promising cultivars. Three separate experiments were conducted on promising cultivars including KVD4, NB2, PH2, beside Quince 3 and KVD3 (the Isfahan quince) as controls. Explants from these cultivars were taken from quince collection orchard of Kamalshahr Research Station in Karaj, surface sterilized and established in vitro for further experiments. In the first experiment, shoot growth and proliferation were evaluated using 3 different culture media, MS, QL and modified QL. The results showed that using modified QL gave the greatest growth and proliferation rates in the shortest possible time with the highest quality compared to other 2 culture media. In the second experiment, the effects of 2 kind of cytokinin, 2iP in 0, 0.5, 1.0 and 2 mg/L and BAP in 0.5, 1.0 and 2.0 mg/L were investigated on shoot growth and proliferation of different cultivars. The result from this experiment revealed that a medium containing 0.5 mg/L 2iP and 1.0 mg/L BAP was superior producing the highest number of micro shoots of high quality. Experiment for root induction conducted with 2 short and long duration of auxin treatments using various concentrations of IBA showed that short term treatment gave better rooting results compared to long term treatment. The highest rooting percentage, leaf development and root quality were obtained using 2.0 mg/L IBA. It was concluded that for micropropagation of studied quince cultivars, a modified QL medium supplemented with 3% sucrose, 1.0 mg/L BAP, 1.0 mg/L 2iP, 0.5 mg/L pectin and 0.6% agar can be recommended. Based on the obtained results from this project, it would be possible to micropropagate the desired quince genotypes for breeding program and if necessary, it could be commercialized in the future.