ESTABLISHING APPROPRIATE PARAMETARS FOR ROOTING OF MICROPROPAGATED PEAR ROOTSTOCK OHF X 333 (PYRUS COMMUNIS L.)

The study was carried out in period September 2016 – April 2017, in laboratory for in vitro propagation of Fruit Growing Institute – Plovdiv. These rootstocks were obtained by hybridization of pear varieties of Old Home X Farmigdale in the American state of Oregon. Micropropagated plants in vitro were rooted on B (Dimanov, 1987) nutrient media in two different forms (solid and liquid with perlite) with different concentration of plants grow up regulators- auxins (IAA and IBA). The results show that the micropropagated plants of this rootstock are highly dependent from the nutrient media composition and concentration of grow up regulators for rooting. Plants with roots was produced 15 – 20 days after cultivated on nutrient media for rooting, but results were reported 30 days after cultivation date . According from forms (solid and liquid) and plants regulators –auxins (IBA and IAA), percent of the rooted plants it is different. nematodes and Phytophtora cactorum . Tolerant of heavy and soils and low and with all rootstocks by of pear varieties of Old x Farmigdale in state