| Vegetative growth and flower bud differentiation are important factors to determine the formation of apple yielded.Plant growth regulators can significantly regulate the vegetative growth and flower budded formation of fruit trees.Prohexadione calcium is a new type of plant growth retarder,CPPU is a kind of high activity enures type cytokinin.In this study,two kinds of regulators were selected.On the basis of clear single use concentration,the combination of spraying one-year-old Malus hupehensis Rehd,five-year-old and eight-year-old Fuji apple plants was used to investigate the vegetative growth and flower bud formation of the plants.The results showed that:1.Spraying 100mg/L,200mg/L,300mg/L,400mg/L and 500mg/L Prohexadione calcium reduced the length of new shoots,increased the number and thickness of new branches,promoted the dry matter accumulation of new shoots,increased root activity,root length,root surface area,root volume,number of branches,fractal dimension,net photosynthetic rate,transpiration rate,chlorophyll content and so on.When the concentration was 300-500 mg/L the effect was more prominent.2.Spraying 50mg/L,100mg/L,200mg/L and 300mg/L CPPU can increase the length,coarseness and branch number of new shoots,promote the dry matter accumulation of new shoots,improve the root activity,chlorophyll content and the net photosynthetic rate of leaves,most index increase more obviously in the concentration of 100-300mg/L;400mg/L CPPU can reduce the new length and the net photosynthetic rate of leaves,reduce the accumulation of new slightly dry matter.3.When the concentrations of 100,200 and 300mg/L Prohexadione calcium were combined with the concentrations of 300,400 and 500mg/LCPPU respectively,the combination of 200mg/L CPPU+500mg/L Pro-Ca had the largest number of new branches,the combination of 300mg/LCPPU+300mg/L Pro-Ca had the best root growth,and the combination of 300mg/LCPPU+300mg/L Pro-Ca and 300mg/LCPPU+500mg/L Pro-Ca had better photosynthetic performance than other combinations.4.In the period of flower bud physiological differentiation of five-year-old apple trees,spraying 300mg/LCPPU+300mg/L Pro-Ca and 300mg/LCPPU+500mg/L Pro-Ca significantly increased the content of soluble sugar,total phosphorus and total potassium in leaves;spraying 100mg/LCPPU+300mg/L Pro-Ca and 300mg/LCPPU+500mg/L Pro-Ca increased the content of ZR,ZR/ IAA,ABA and ABA / IAA in shoots;spraying 300mg/LCPPU+500mg/L Pro-Ca increased the flower bud rate by 1.7 times.5.At the physiological differentiation stage of eight year old apple tree flower bud,spraying 300mg/LCPPU + 500mg/L Pro-Ca significantly increased the sucrose content,ZR content,ZR/ IAA,α-amylase activity,the quantity and quality of plant top bud,the percentage of plant flower bud,etc.,and promoted the formation of apple plant flower bud. |
