Establishment Of Regeneration System From Leaves In Vitro Of Pingguoli(Pyrus Reschneideri Rehd)

Pingguoli, plant of Rosacene, Pyrus L. which is the main pear cultivars in Yanbian area. A stable and efficient regeneration system is one of the key link of transcription breeding. This paper studied the factors affect the establishment of Pingguoli tissue culture and regeneration system, and the results is as follows:1. The suitable sterilization time for different source-explants is different. The best sterilization time for the water-cultured shoot is2minutes, for the germination stage shoot is3minutes, and for the dormant buds is5minutes. The suitable starting culture media for the water-cultured buds and germination stage buds is1/3MS+1.0mg·L-16-BA+0.2mg·L-1IBA+75mg·L-1V c, and the germination rate is up to60.12%and59.85%respectively. And the optimum media for the dormant buds is MS+1.5mg·L-16-BA+0.3mg·L-1IBA+7.5mg·L-1GA, and meantime the germination rate can reach to89.62%. However it appears no multiplication for all three kinds of explants during the initial culture, so it is necessary to transfer the explant to themultiplication medium in time.2. The best multiplication medium for water-cultured and germination stage buds is1/2MS+1.5mg·L-16-BA+0.3mg·L-1NAA, and the multiplication coefficient is respectively is5.12and4.89, but the dormant buds differes from the others. The dormant buds should be cultured on both of1/2MS+1.5mg·L-16-BA+0.3mg·L-1NAA and NN69+1.0mg·L-16-BA+0.3mg·L-1NAA media, which is used alternatively. Under this case, the multipli-cation coefficient just reaches to4.0. The suitable differentiation explant is leaves with subcultured more than4times.3. The optimum medium for Pingguoli leaves regeneration is NN69+1.5mg·L-1TDZ+0.4mg·L-1NAA, and leaf differentiation ability was better than petiole and stems without buds after20days of dark culture. The regeneration frequency and mean number of buds per leaf are71%and2.21. Then transfer the adventious buds to the media of1/2MS+1.5mg·L-16-BA+0.3mg·L-1NAA, the growth status is good and the multiplication coeffience is4.52.4. Transfering the plantlet to the rooting media of1/4MS+1.5mg·L-1IBA. It appears that the rooting status of the plantlet is good and combined with8day-darkness culture,the average booting rate is52.65.