Response Of ’Fuji’apple Saplings To Nutrient Stress On Different Dwarfing Interstocks

Dwarfing and close planting is the main mode of apple industry development in the world today.At present,dwarf interstock is mainly used in apple dwarfing in China.The soil quality and soil fertility in the main apple producing areas in China are poor,which is not conducive to the growth and development of fruit trees.Screening and cultivating apple trees which have tolerance on nutrient stress is helpful to achieve high quality and efficient production of dwarfing and close planting.The experiment was carried out in the Innovation Demonstration Park of Agricultural University of Hebei,the base stock of the test material is Grabapple,grafting different interstocks(SH40,Jizhenl,Jizhen2,24-5,181,53),the scions were ’Tianhong2’.By measuring the morphological and physiological indexes of apple saplings treated with different concentrations of nutrient solution,the growth difference of ’Fuji’ apple saplings with different dwarf interstocks under nutrient stress was investigated.The main results are as follows:1.The effects of different concentrations of nutrient solution on the morphological indexes of apple saplings were studied,the results show that,compared with the control(1/2 concentration of Hoagland nutrient solution),apple saplings treated with 1/4 concentration of Hoagland nutrient solution in 2019 with SH40,Jizhenl,Jizhen2 and 24-5 as intermediate stocks had significant increases in plant height and growth,and the increase ranges were SH40 and Jizhenl>.Jizhen2 and 24-5,the total dry weight and relative growth rate decreased significantly,and the decreasing rates were SH40 and jizhenl<Jizhen2 and 24-5;the above indicators of apple saplings with 181 and 53 as interstocks decreased significantly;under the treatment of 1/8 concentration of Hoagland nutrient solution in 2019,the above indexes of apple saplings with SH40,Jizhenl,Jizhen2,24-5,181 and 53 as intermediate stocks all decreased significantly,with the decreasing amplitude of SH40 and Jizhenl<Jizhen2 and 24-5<181 and 53;the results of treatment with 1/8 nutrient solution and 1/32 nutrient solution in 2020 were similar to those of treatment with 1/8 nutrient solution in 2019.2.The effects of different concentrations of nutrient solution on the photosynthetic characteristics,root activity and endogenous hormones of apple saplings were studied,the results show that,compared with the control,the photosynthetic rate,chlorophyll concentration,root activity,Zeatin Riboside(ZR),Gibberellin(GA3),Auxin(IAA)and Abscisic Acid(ABA)of apple saplings treated with 1/4 nutrient solution in 2019 with SH40,Jizhenl,Jizhen2 and 24-5 as intermediate stocks were significantly increased,the increase rate was SH40 and Jizhenl>Jizhen2 and 24-5;the above indexes of apple saplings with 181 and 53 as interstocks decreased significantly;under the treatment of 1/8 concentration of nutrient solution in 2019,the above indexes(except ABA)of apple saplings with SH40,Jizhenl,Jizhen2,24-5,181 and 53 as intermediate stocks were significantly decreased,with the decrease rate of SH40 and Jizhen1<Jizhen2 and 24-5<181 and 53;the content of ABA increased significantly,with a range of 181 and 53>Jizhen2 and 24-5>SH40 and Jizhenl;the results of treatment with 1/8 nutrient solution and 1/32 nutrient solution in 2020 were similar to those of treatment with 1/8 nutrient solution in 2019.3.The effects of different concentrations of nutrient solution on mineral elements of apple saplings were studied,the results show that,compared with the control,the concentration,absorption,transfer rate,accumulation amount and distribution of mineral elements in apple saplings treated with 1/4 nutrient solution in 2019 with SH40,Jizhenl,Jizhen2,24-5,181 and 53 as intermediate stocks were significantly decreased,and the decreasing rates were SH40 and Jizhen1<Jizhen2 and 24-5<181 and 53;the results of 1/8 concentration nutrient solution treatment were consistent with those of 1/4 concentration nutrient solution treatment,while the results of 1/8 concentration nutrient solution treatment and 1/32 concentration nutrient solution treatment in 2020 were similar to those of 2019.4.According to the response degree of rootstocks to different concentrations of nutrient solution,it was concluded that ’Tianhong 2’/SH40/Carbapple and ’Tianhong 2’/Jizhen1/Carbapple were the most resistant to nutrient stress;Tianhong 2’/Jizhen2/Carbapple and ’Tianhong 2’/24-5/Carbapple were more resistant to nutrient stress;’Tianhong 2’/181/Carbapple and ’Tianhong 2’/53/Carbapple were not tolerant to nutrient stress.