Study On The Effect Of Virus-free Apple Seedlings In The Replanting Land

In this study,virus-free ‘Yanfu 3' apple seedlings grown in replanting land were used to study the effect of replanting land on apple seedling.The common ‘Yanfu 3' apple seedlings was used as contrast.Cropping increment,chlorophyll content,photosynthetic rate,leaf antioxidase activity and leaf mineral nutrients of apple seedlings and the production and quality of fruits were detected.The main results were as follows.1.There is no ASGV? ASPV? ACLSV or ASSVd virus found in virus-free ‘Yanfu 3' apple seedlings in replanting orchards while the infection and complex infection rates of virus in common ‘Yanfu 3' apple seedlings were 90% and 55%,respectively.2.In replanting land,the increment of virus-free ‘Yanfu 3' apple seedlings was higher than common ‘Yanfu 3' apple seedlings.The results indicated that the trunk girth of virus-free ‘Yanfu 3' apple seedlings was 0.66,0.47 and 0.66 times higher than common ‘Yanfu 3' apple seedlings in 3 continue years,respectively.The plant height of virus-free ‘Yanfu 3' apple seedlings was 0.35,0.39 and 0.52 times higher than common ‘Yanfu 3' apple seedlings in 3 continue years,respectively.The main branch quantity of virus-free ‘Yanfu 3' apple seedlings was 0.93,1.22 and 0.64 times higher than common ‘Yanfu 3' apple seedlings in 3 continue years,respectively.The length of main branch of virus-free ‘Yanfu 3' apple seedlings was 0.85,0.58 and 0.51 times higher than common ‘Yanfu 3' apple seedlings in 3 continue years,respectively.The thickness of main branch of virus-free ‘Yanfu 3' apple seedlings was 0.5,0.59 and 0.54 times higher than common ‘Yanfu 3' apple seedlings in 3 continue years,respectively.In a word,the increment of virus-free ‘Yanfu 3' apple seedlings was higher than common ‘Yanfu 3' apple seedlings grown in replanting land significantly.3.Three treatments,microorganism fertilizer,carbendazol and coating,were used when the virus-free ‘Yanfu 3' apple seedlings and contrast apple seedlings planted.After using microorganism fertilizer or carbendazol in the same year,the thickness,height and leaves weight of virus-free ‘Yanfu 3' apple seedlings were higher than contrast apple seedlings,meaning that virus-free has significant effect on overcoming the obstacle of grown in replanting land.4.The photosynthetic characteristics in both ‘Yanfu 3' apple seedlings were measured in the third year(2016).The chlorophyll content,transpiration rate,stomatal conductance and intercellular CO2 concentration of virus-free ‘Yanfu 3' apple seedlings grown in replanting land were 4.72%-17.96%,3.81%-10.38%,4.02%-13.06% and 9.1%-23.5% higher than contrast apple seedlings,respectively.The photosynthetic characteristics in virus-free ‘Yanfu 3' apple seedlings was better than contrast apple seedlings.5.The chlorophyll content,transpiration rate,stomatal conductance and intercellular CO2 concentration of virus-free ‘Yanfu 3' apple seedlings grown in replanting land were 4.72%-17.96%,3.81%-10.38%,4.02%-13.06% and 9.1%-23.5% higher than contrast apple seedlings,respectively.The photosynthetic characteristics in virus-free ‘Yanfu 3' apple seedlings was better than contrast apple seedlings.6.The autioxidant enzyme activities in leaves in both ‘Yanfu 3' apple seedlings were measured in the third year(2016).The activity of SOD,POD and CAT of virus-free ‘Yanfu 3' apple seedlings grown in replanting land were 13.86%-52.78%,16.1%-30% and 17.5%-90.5% higher than contrast apple seedlings,respectively,indicating that the tolerance of virus-free ‘Yanfu 3' apple seedlings in replanting land was stronger than contrast apple seedlings.7.The mineral nutrition contents in leaves in both ‘Yanfu 3' apple seedlings were measured in the third year(2016).The contents of nitrogen,calcium,magnesium,manganese and zinc in virus-free ‘Yanfu 3' apple seedlings leaves were 27.9%,16.7%,20.7%,9.9%,36.8% and 37.9% higher than common ‘Yanfu 3' apple seedlings leaves,respectively.The contents of potassium in virus-free ‘Yanfu 3' apple seedlings leaves was 9.35% lower than common ‘Yanfu 3' apple seedlings leaves.Virus-free can increase the absorption and utilization of mineral nutrition.8.Taking advantage of the strong growth of virus-free ‘Yanfu 3' seedlings,the experiment innovates the plastic pruning model to realize the synchronous growth of seedlings with early high yield.Using the improved-spindle,the yield of virus-free ‘Yanfu 3' was 1292 kg,while the yield is 271.7kg using the freedom spindle,indicating that improved-spindle is useful in early high yield.The hardness,contents of soluble solid,contents of soluble sugar have no significant difference between the two kinds of apple seedlings,but the titratable acid content has significant difference.Virus-free ‘Yanfu 3' seedlings have early high yield and have a considerable yield in the forth year.