Research On The Hardwood Cutting And Rapid Propagation In Vitro Of Pear

Seedlings are the material basis for the development of fruit production. Seedlings of fruit trees have identical genetic materials, which can keep the maternal plants desirable traits and characters, and they have the advantages of early bearing and high yield. Seedlings have been widely used as the preferred type for the the establishment of high-standard orchard in the fruit industry developed countries.In this study, the one-year-old branches of Pyrus betulaefolia Bge., OHF97, OHF333, Qingai 3, Zhongai 1, Yunnan quince(Cydonia Oblonga Mill.), Abate Fetel Pear, Dangshan Pear and Hongxiangsu pear were used as the experiment materials, the Pyrus betulaefolia Bge., OHF97, OHF333 and Abate Fetel Pear were treated with different concentrations of IBA and ABT, the Hongxiangsu pear and Dangshan Pear were treated with different length of cuttings, and Yunnan quince were treated with different diameter of cuttings, then the germination and survival rate of the treated cuttings were counted; Simultaneously, in order to study the breeding of the self-root seedlings, the shoots of Zhongai 1 and OHF333 were used as the explants for the in vitro culture and rapid propagation.The main results are as follows:1. Cutting propagation of Pyrus rootstocksDifferent types, concentrations of hormone have different impact on the the rate of germination and survival of the cuttings of Pyrus betulaefolia Bge.. The treated cuttings had higher rate of germination and survival than control, showed that the hormone promoted the rooting and germination. With the increase of concentration of IBA and ABT(below 200 mg/L), the rate of germination and survival of the cuttings rose, but when the concentration of them was 300 mg/L, the rate of germination and survival decreased, the results indicated that high levels of the hormone are toxic to Pyrus betulaefolia Bge.. With the same concentration, IBA had a higher rate of germination and survival than ABT. Therefore, the most suitable hormone for the pyrus betulaefolia was 200 mg/L IBA, the germination rate was 81.8%, with the survival rate 68.2%, which were higher than other treatment. In addition, when the diameter of cutting was less than 5 mm or more than about 15 mm, the root number of cuttings was less, the root is shorter, when the diameter of the cuttings of Pyrus betulaefolia Bge.was 10 mm, the roots were robust and developed.The survival rate of other Pyrus rootstocks were not high; the highest survival rate of OHF333 was the treatment with 200 mg/L ABT, the survival rate was 30%; for OHF97, 200 mg/L ABT had the highest survival rate(20%); while both the survival rate of Qingai 3 and Zhongai 1 were 0.2. Cutting propagation of Cydonia Oblonga rootstocksWith the increase of diameter of cuttings, the germination and survival rate of Yunnan quince cuttings increased, when the diameter of cuttings was 10 mm, the germination rate was 86.7%.3. Cutting propagation of pear cultivarsThe cuttings of pear cultivars were difficult to survival; the survival rate of Abate cuttings was the treatment with 100 mg/L ABT, the survival rate was only 20.0%; the cutting of Hongxiangsu pear and Dang Shan pear cannot survive.4. In vitro propagation of pear rootstocksThe optimum proliferation medium of Zhongai 1 was MS+6 ﹣ BA 1.0mg/L+IBA 0.3mg/L, with proliferation coefficient 3.38; while the optimum rooting medium was 1/2MS+NAA 0.1mg/L, with rooting rate 50.1% and transplanting survival rate 66.0%; The optimum medium for the shoots multiplication of OHF333 was MS+6﹣BA 1.0mg/L+IBA 0.3mg/L, with proliferation coefficient 3.71; while the optimum rooting medium was 1/2MS+NAA 0.5mg/L, the rate of rooting and transplanting survival were 52.6% and 78.0%, respectively.