Studies On Characteristics Of Growth And Fruit And Cold Harkiness Of Korla Fragrant Pear And Bud-sport Strains

Taking the Bud-sports strain of Korla fragrant pear, dwarf rootstocks and Korla fragrant pear as the materials, the growth and fruits set characteristics, fruit qualities and cold hardiness of Bud-sport strains, the xenia function of 10 pollinated varieties on Korla fragrant pear and effects of middle-dwarfed rootstocks on Bud-sport 9 have been studied. The main results can be summarized as follows.1. Among the five Bud-sport strains:Sha01, ShaO2, ShaO3, Bud-sport 6, Bud-sport 9, Bud-sport9 which has no enation on fruits'calyculus and the single fruit weight is 152.37 g, harvests 20 days earlier than Korla fragrant pear. It has abundant Vc content of 18.24mg/100g and 11 amino acids, including 3 essential amino acids, which take 14.3% of the total amino acids. The Bud-sport 9 with high fragrance content are suitable for publicity as a kind of excellent Bud-sport strains.2. The pollination study indicates that the fruits set rate reaches to the lowest level of 25.49% when taking Bali as the pollinizer, but the others'fruits set are over 60%. Korla fragrant pears which were pollinated by Dangshanli, Pingguoli and 81-15-10 showed better business characters such as big fruit size and high fruit quality. The single pear weight can reach to 112.31g when pollinated by Pingguoli, the commercial rate can reach to 88% and the soluble sugar and fragrant substance content can reach to the highest when pollinated by Dangshanli, the revertose, Vc and amino acids content are highest when pollinated by 81-15-10, the titratable acid content is highest when pollinated by Zaosu, the stone cell content is lowest when pollinated by Bali. The Dangshanli, Pingguoli and 81-15-10 can be configured as the pollinizer.3. Taking the S2 dwarf rootstock as the middle rootstocks, Bud-sport 9 appears lower height, smaller crown and bigger diameter of the basal fresh branch, especially when the length of S2 is about 36 to 40cm. The S2 and S5 dwarf rootstock have the effects of increasing the fruits size and amylum content, reducing the stone cell content, and also can shorten the juvenile period for 1 to 2 years.4. Taking the S2 and S5 as the middle rootstocks, the LT50 of Bud-sport 9, which are-23.5℃and-23.3℃separately, are lower than other Bud-sport strains. When treated at-22℃, the soluble sugar content are highest when grafted with S2, the proline and soluble protein content are highest with the MDA content is lowest when grafted with S5. It concludes that dwarf rootstock S2 and S5 can increase the cold hardiness ability of Bud-sport 9.