Studies On The Characteristics Of Nitrogen Metabolism During The Fruit Development Of Sweet-cherry (Prunus Avium L.)

In order to provide a theoretical and practical basise that how to apply fertilizer in a rational way and achive high yield and high quality of sweet-cherry,"Hongdeng"(Prunus. aviumL. var.Hongdeng) was used in the experiment as research materials.The experiment was done in Shandong Agricultural University between 2009 and 2010.Using ¹⁵N stable isotope tracer technique to study the critical period of development in the fruit of spraying into the various organs of ¹⁵N -urea fertilizer absorption,distribution and utilization characteristics.Studing on the effect of growth and development of sweet cherry in the different forms of nitrogen with the controlle of release fertilizer.The main results were as follows:1. Most uptake of ¹⁵N by leaves occurred during the first 6 hours following application of urea.The mean rate of absorption during these 6 hours was 0.11503 mg/g·h. ¹⁵N content peaked 24 hours(0.9353mg/g) after urea application and then decreased。¹⁵N content in Lower leaves and new shoot peaked 24 hours and the content of them were same.The ¹⁵N content of younger leaves was higher than lower leaves and new shoot and the content was stable with none of obvious peak.This showed that:The absorption and running of ¹⁵N-urea can occur at the same time, the absorption mainly occured within 24h after the application.2. The peak of every organ Ndff% achieved in 24hours and then with a decrease the Ndff% made a stable at last.After applied ¹⁵N-urea 168 hours,the Ndff% of organs was:new shootï¹¥younger shootï¹¥lower shoot.This shows that:Appling urea in early spring,the ¹⁵N-urea that absorbed by sweet-chreey distribut to new shoot and younger leaves in priority and just little transport to lower organs.3. The absorption of ¹⁵N-urea in leaves of different parts was different. The front+the back can absorbed the highest ¹⁵N,the back followed and the front is the lowest.The different part of leaves absorbed quickly in 6 hours and with a peak in 48 hours then started to decrease.The ¹⁵N content in the front stabled in a lower level and his peak happened in 48 hours(0.2081mg/g·DW).4. Applied ¹⁵N -urea in the fruit development ,the ¹⁵N priority assigned to the new organs (leaves, shoots, fruit) in the form of new organs for the plant construction. In the fruit enlargment stage,the Ndff% of leaves were the highest and new shoot followed(0.31%),the fruit is the third(0.22%);When the fruit came to the hardcore stage,the Ndff% of the fruit increased to 1.87% and just lower than the leaves of perennial branches and two years old branches(2.04%,2.03%);In the mature fruit color stage, the leaves of two years old branches was the highest(2.05%),and younger shoot(1.92%) and fruit(1.91%)followed.In fruit ripe stage,younger shoot was the highest(2.62%), new shoot(2.26%) and two years old branches(2.22%) followed.The fruit was the third(1.97%).5. In the fruit enlargement stage, ¹⁵N mainly accumulated in the perennial leaves (including the biennial and perennial foliage leaves, the same below) based on vegetative organs, 92% of the total absorption, fruit, followed by the 0.0799%, ¹⁵N mainly sinotrans to leaves, shoots and other organs in the newborn; In the Hardcore stage, ¹⁵N distribution rate remains the highest perennial leaves, is 52.33%, followed by fruits (23.06%); In the Color stage and the ripe stage, ¹⁵N distribution rate were perennial leaves> new organs> Fruit> perennial branches.6. Different forms and methods of fertilizer significantly increased leaf dry weight, fresh weight, leaf area, chlorophyll content and specific leaf weight. T1 treatment leaf fresh weight, dry weight was increased by 18.7%, 51.42%, leaf area increased by 46.44%; Ammonium handling all the chlorophylla content, and compared with the control CK1, increased 6.69%, compared with the full nitrate treatment increased 12.11%, but all the chlorophyll b content of ammonium treatment and control (CK1, CK2) significant difference, increased 28.99 %, 15.58%; From the beginning period ofâ…¡, specific leaf weight of each treatment and control differences between the growth rate significantly, to the fastest growth rate of amino acid liquid fertilizer, to the period whenâ…³, T1 growth rate of 106.44 percent, as CK1, CK2 was 2.08, 1.70.7. T1 processing soluble sugar and protein was the highest compared with the control increased by 187.55%, 36.14%. T2 treatment also promoted the accumulation of nitrate plant body, 1.72 times the control. T1 and T4 treatment significantly inhibited the accumulation of nitrate in leaves compared with the control decreased 37.65%, 41.53%; each treatment have contributed to the accumulation of ammonium nitrogen in the body to the most significant T1 and T2, respectively, in control 2.67 times, 2.51 times. 8. NR activity of T1 treatment higher than CK1, CK2, respectively, 50.41%,40.79%, the significant difference between nitrogen forms, state, and amide amino nitrogen were significantly higher than that of a single state of NO₃^-N,NH₄⁺-N.The four forms of nitrogen in the , NH₄⁺-N treatment were the lowest NR activity.Early fruit development, full-ammonium treatment (T4), amino acid fertilizer treatment (T1) deal with other significant difference between GDH activity in the hard core of an increase of 20.58% compared to the control and 18.19%, 18.41% and 15.96%.The GOT and GPT activity of T1 is the largest and the longest sustained high activity in the ripe stage.9. All treatments increased fruit quality, the treatment effect of T1 is the most significant .And compared with the control, fruit weight, soluble solids, sugar acid ratio, soluble sugar, VC increased by 12.97%, 14.93% and 77.97% 28.7%, 6.54%. Titratable acidity decreased 35.19%.