Study On Characteristics Of A Trophic Variant In Gala Series

Apple is a plant of Family Rosaceae and Subfamily Pomoideae of Malus. Shaanxi is the main domestic high-quality apple concentration. Along the continuous development of economic and trade, shaanxi apple had a "Lack of early apples, short of middle apples, excess of late apples" variety structure. The late apples accounts for 82%, the middle apples accounts for 14%, the early apples just accounts for 4% in Shaanxi recently. Therefore, it has a practical significance to cultivate high-quality early apples, in order to balance the apple varieties and develop the economy of apples.The experiment carried on in a orchard at Shanyang village, Wangcun Town, Heyang county, Weinan city, Shaanxi Province. The object of study was a new trophic variant of code "GB-1" in Gala series, with Gala, Senshu and Hokudo as check. Compare the botanical and agricultural characteristics, cold-resistance ability, storability between GB-1 and Gala, Hokudo, Senshu. The botanical and agricultural characteristics were investigated. Protective enzymes activity and osmotic adjustment substances were measured under low temperature gradient to evaluate the cold-resistance ability. The internal quality were measured during the cold storage to evaluate the storability. Different treatments of fertilizer applied were set to GB-1 at early summer, in order to compare the effects on growth and quality of GB-1, then the best fertilizer treatment of GB-1 was get during early summer. The results are as follows:1. The new trophic variant GB-1 has almost the same botanical and agricultural characteristics with Gala. The average weight, soluble solid content, vitamin C content was higher than the original variety, with significant difference. The quality of GB-1 is better than Gala. The GB-1's phenological phase is earlier than Gala's. The bud sprouting was promoted by one week and the maturity was promoted by two weeks, in the middle of July.2. After sub-zero cooling process, the relative conductions, MDA content, protective enzymes activity of branches were measured. The relative conductions, MDA content, soluble sugar content increased during the process and protective enzymes activity changed with curve. The result shows the cold-resistant ability of four apples was listed in descending order as follows:Senshu>Hokudo>GB-1>Gala.3. During the cold storage, internal quality was measured. The firmness, soluble solid content, titratableacid content, Vc content decreased and the weight-loss ratio increased during the storage. All varieties had respiratory climacteric, which is early in Gala's and late in Senshu and Hokudo. GB-1 was greater than Gala at firmness, soluble solid content, Vc content, titratableacid content. During the early 70d of cold storage the weight-loss ratio of GB-1 was low, and it increased in the 20d left, the same as Gala. Both the respiration rate was almost the same, and the difference was not significant. Above all, the storability of GB-1 and Gala were almost the same.4. The 7 years old GB-1 in Gala series was fertilized during rapid-expanding stages. The result showed that the most suitable rate of urea is 1.0kg/plant-1.5kg/plant, and the NPK fertilizer (N:P:K=2:2:3) is 1.5kg/plant-2.0kg/plant, and the compound fertilizer for fruit tree only (N:P:K=8:12:15) is 1.5kg/plant-2.0kg/plant.