Evaluation Of Nitrogen Utilization Ability Of Tomato Rootstock And Its Effect On Nitrogen Uptake And Utilization Efficiency

This experiment had collected 25 line of tomato rootstocks to identify the ability of nitrogen utilization.On this basis,we selected these rootstocks of different ability of nitrogen utilization to cultivate by grafting,which to test the growth and development,production and quality,characteristic of photosynthetic,nitrogenous metabolism of different grafted tomatoes under different nitrogen levels.The main results as follows:1.The plant height,stem diameter,root,stem,leaf dry weight and nitrogen content of 25 tomato rootstock were significantly different under different nitrogen supply conditions.The nitrogen absorption,nitrogen fertilizer partial productivity and nitrogen utilization efficiency were also obvious different.The nitrogen use efficiency of tomato rootstock was used as the statistical parameter to cluster analysis.The results showed that the nitrogen utilization efficiency of the tested tomato rootstock was divided into three groups: high,medium and low.The results of clustering at the medium and low nitrogen levels were consistent.The results of cluster analysis at high nitrogen level showed a significant increase in the material with high nitrogen utilization efficiency.The results showed that the clustering results of nitrogen yield and nitrogen absorption were basically the same as those of nitrogen utilization efficiency.Comprehensive analysis showed that ’TMS-150’ material has a strong nitrogen use capacity,’0301111’ and ’Ying Wuzhe’ materials have a weak ability to use nitrogen,and other materials are centered.2.The growth,production and quality of tomato grafted with different rootstocks were higher than those of scion ’Jin Peng 1’.The fruit weight of grafted tomatoes of taking ’TMS-150’ and ’0301111’ as roostocks increased by 53.64% and 26.58% respectively,and the production of per plant increased by 45.46% and 24.68% respectively.The fruit soluble sugar,Vc and organic Acid content was also significantly higher than the self-rooted seedlings.Under 40 kg / 667 m2 of nitrogen fertilizer application,the plant height,stem diameter,root,stem,leaf and fruit weight,soluble sugar,soluble protein of tomato were better.The content of Vc,organic acid and lycopene in fruit decreased with the increase of nitrogen application.3.The pigment content,net photosynthetic rate,actual photochemical efficiency and maximum photochemical efficiency of grafted tomato leaves were significantly higher than those self-rooted seedlings,but the low temperature season showed a decreasing trend,especially in January.The diurnal changes of Pn and Gs in tomato leaves showed a single peak curve.Under 40 kg/667 m2 of nitrogen fertilizer application,the pigment content,photosynthetic rate and fluorescence parameter of tomato leaves were the highest.Decreasing or excessive nitrogen application resulted in a decrease in photosynthetic capacity.Under 20,40,60 kg/667 m2 of nitrogen fertilizer application,the diurnal changes of photosynthetic parameters Pn and Gs showed a single peak curve.But under 0 kg/667 m2 of nitrogen fertilizer application,Pn and Gs showed a bimodal curve,appeared "photosynthesis lunch break".4.The activities of GS,GOGAT and GDH in the leaves of grafted tomato were enhanced,and the contents of nitrate nitrogen,ammonium nitrogen,free amino acid nitrogen and protein nitrogen were increased,and the grafts of taking ’TMS-150’ as rootstocks with high nitrogen use ability were higher,nitrogen use capacity of weak ’0301111’ grafted seedlings followed,since the self-rooted seedlings lower.The key enzyme activities of nitrogen metabolism were different with the growth season,and the low temperature season was lower.But the critical components of nitrogen metabolism increased gradually with the growth.The key enzyme activities and the content of key components in nitrogen metabolism increased with the increase of nitrogen application rate,which was better under 40 kg/667 m2 of nitrogen fertilizer application and declined with nitrogen fertilizer application increased to 60 kg/667 m2.5.Grafting of different rootstocks improved the nitrogen utilization ability of tomatoes.The nitrogen content of plant root,stem and leaf,nitrogen absorption,nitrogen fertilizer partial productivity,nitrogen fertilizer agriculture efficiency and nitrogen utilization efficiency were excellent in the grafted seedlings of ’TMS-150’ with high nitrogen use ability,which were higher significantly than ’0301111’ grafted seedlings with weak nitrogen utilization ability.The nitrogen absorption of both increased by 63.77% and 32.97% respectively,fertilizer partial productivity increased by 45.47% and 25.83% respectively,nitrogen fertilizer agriculture efficiency increased by 63.35% and 44.99% respectively,nitrogen utilization efficiency increased by 37.36% and 21.04% respectively.The nitrogen fertilizer partial productivity,nitrogen agriculture efficiency and nitrogen utilization efficiency of tomato decreased with the increase of nitrogen application.But the nitrogen content of plant root,stem and leaf and nitrogen absorption were better under 40 kg/667 m2 of nitrogen fertilizer application.