Nitrogen Absorption And Utilization Of Three Peach Rootstocks

Nitrogen is an essential nutrient element in the growth and development of fruit trees,which has an important impact on the growth and development of fruit trees,fruit yield and quality.In peach production,fruit growers are one-sided pursuit of yield,and excessive nitrogen application is common.Excessive application of nitrogen leads to the decline of peach fruit quality and the occurrence of physiological diseases,which not only restricts the high quality and yield of peach,but also causes serious environmental pollution.Improving nitrogen absorption and utilization efficiency can reduce the input of nitrogen fertilizer,and it is very important to screen peach rootstock resources with high nitrogen utilization efficiency for improving nitrogen utilization efficiency.Therefore,the characteristics of nitrogen absorption and utilization of 1-year-old peach seedlings and 1-year-old Peach Rootstocks’Shannong 1’and’Shannong 2’cuttings and their grafted seedlings’Ruipan 21/Maotao’,’Ruipan 21/Shannong 1’and’Ruipan 21/Shannong 2’were studied by ¹⁵N tracer technique.In order to screen nitrogen efficient rootstock resources and provide theoretical guidance for improving nitrogen use efficiency.The main research results are as follows:1.Differences in nutrient absorption and utilization of three peach rootstocks and grafted seedlings.Compared with peach,the content of alkali-hydrolytic nitrogen,available phosphorus and available potassium in pot soil of’Shannong 1’were 11.90%,12.12%and29.38%lower,respectively,and the differences were significant.The contents of alkali-hydrolytic nitrogen,available phosphorus and available potassium in pot soil of’Shannong 2’were 6.36%,6.37%and 18.49%lower,and the differences were significant.Compared with’Ruipan 21/Maotao’,the content of alkali-hydrolyzed nitrogen in pot soil of’Ruipan 21/Shannong 1’was 11.34%lower,and the content of available phosphorus was23.31%lower,with significant differences.The content of alkali-hydrolyzed nitrogen in pot soil of’Ruipan 21/Shannong 2’was 9.53%lower,the difference was significant,and the content of available phosphorus was 2.84%lower,the difference was not significant.Nitrogen was mainly distributed in roots of several Peach Rootstocks and their grafted seedlings.Compared with Maotao,the nitrogen use efficiency of’Shannong 1’was 6.7%higher,with significant difference;the nitrogen use efficiency of’Shannong 2’was 7.68%higher,with significant difference.Compared with’Ruipan 21/Maotao’,the nitrogen use efficiency of’Ruipan 21/Shannong 1’was 4.44%higher,the difference was significant;the nitrogen use efficiency of’Ruipan 21/Shannong 2’was 2.42%lower,the difference was significant.The results showed that peach rootstock’Shannong No.1’was a high nitrogen efficient rootstock resource.2.The contents of nitrogen,phosphorus and potassium in three peach rootstocks and grafted seedlings.Compared with the Maotao,’Shannong 1’had a 9.01%higher total nitrogen content,24.05%higher total phosphorus content and 9.73%higher total potassium content,with significant differences.Compared with Maotao,’Shannong 2’had 4.57%higher total nitrogen content and 13.75%higher total phosphorus content.Compared with’Ruipan 21/Maotao’,’Ruipan 21/Shannong 1’had 10.46%higher total nitrogen content and 13.03%higher total potassium content,and the difference was significant.Compared with’Ruipan 21/Maotao’,the total nitrogen content of’Ruipan 21/Shannong 2’was lower by 15.44%,and the total phosphorus content of’Ruipan 21/Shannong 2’was lower by 6.52%.3.Dry matter accumulation characteristics of three peach rootstocks and grafted seedlings.Compared with Maotao,’Shannong 1’had 17.69%higher total dry weight and 15.38%higher root shoot ratio,with significant difference;The total dry weight of’Shannong 2’was 17.16%higher than that of Maotao,the difference was significant,the root shoot ratio was 3.85%lower,the difference was not significant.Compared with’Ruipan 21/Maotao’,the total dry weight of’Ruipan 21/Shannong 1’was 13.99%higher,and the root-shoot ratio was 13.24%higher,which showed significant differences.Compared with’Ruipan 21/Maotao’,the total dry weight and root shoot ratio of’Ruipan 21/Shannong 2’were 9.46%and 11.76%higher,respectively.4.The response characteristics of root growth of peach rootstocks and grafted seedlings to nitrogen were different.Compared with Maotao,’Shannong 1’had significantly higher root length,root tip number,cross number,total surface area and root activity by 31.49%,19.75%,21.47%,49.45%and 16.14%respectively.There was no significant difference between’Shannong 2’and Maotao.Compared with’Ruipan 21/Maotao’,the total root length,number of root tips,total surface area and root activity of’Ruipan 21/Shannong 1’were 10.35%,11.26%,12.05%and 10.57%higher,respectively.There was no significant difference between’Ruipan/21 Shannong 2’and’Ruipan 21/Maotao’.Compared with peach,the developed root system is the biological basis for efficient nitrogen absorption of peach rootstock.5.SPAD value and photosynthetic characteristics of three peach rootstocks and grafted seedlings.Compared with the Maotao,the SPAD value of leaves of’Shannong 1’was 6.80%higher,and the net photosynthetic rate of leaves was 18.24%higher in the middle growth period,with significant differences,while the SPAD value of’Shannong 2’leaves was 8.27%lower and the net photosynthetic rate of leaves was 12.45%lower,the difference was significant.Compared with’Ruipan 21/Maotao’,the leaf SPAD value of’Ruipan 21/Shannong 1’was 7.83%higher and the leaf net photosynthetic rate was 15.65%higher in the late growth stage,which showed significant difference.The SPAD value of leaves of’Ruipan21/Shannong 2’was 3.62%higher,and the net photosynthetic rate of leaves was 8.64%higher,with no significant difference.