Physiological Mechanism And Compensation Effects Of Nitrogen Deficiency During Tillering Stage In Double-season Super Hybrid Rice

This project previous studies have shown that tillering is the nitrogen sensitive stage of double cropping super hybrid rice.In order to gain further understanding of double cropping super hybrid rice varieties compensation effects of nitrogen stress physiological mechanisms of formation,This was chosen in double cropping super hybrid rice plant nitrogen sensitive stage process following five:Not all growth stages N treatments T0, Different growth stages in terms of volume distribution T1,N supply is not restored after treatment T2 deficit,After constant deficit for nitrogen recovery process T3, after the deficit times the amount of nitrogen recovery process T4.Examine each process yield and its components, dry matter production, accumulation and allocation, photosynthesis, chlorophyll content, nitrogen metabolism enzyme activity, endogenous hormones and other indicators.The results show:In 2014,Rice Ganxin 203 at panicle initiation stage deficit,Heading compensation processing plant yield T3, T4 and T1 the whole growth period of nitrogen application had significant difference,It showed insufficient compensation.In 2015 rice Ganxin 203 at tillering deficit,Panicle initiation stage compensation processing T3,T4 plant yield respectively than after the deficit is not compensated T2 increase of 17.4%, 38.5%;In the case of the total amount of nitrogen equal,Times the amount of the compensation process T4 yield per plant is higher than the growth period of nitrogen T1, showing the same amount of compensation effect.Show panicle initiation stage is critical effective yield of super hybrid rice compensation.In 2015, Wufengyou T025 at tillering deficit,Panicle initiation stage compensation processing T3, T4 plant yield respectively than after the deficit is not compensated T2 increase 53.3%, 79.1%,In the case of the total amount of nitrogen equal,Times the amount of the compensation process T4 yield per plant is higher than the growth period of nitrogen T1, showing the same amount of compensation effect.Nitrogen deficiency compensation process T3, T4 tillers and leaf area, root activity Significantly higher than the deficit is not compensated processing T2, Compensation process T4 tillers root activity higher than growth period Nitrogen treatment T1.Rice Ganxin 203 Nitrogen is not the whole growth period T0,After the deficit without compensation process T2 With the development of the fertile phase of chlorophyll content decreased,The deficit compensation process T3, T4,Nitrogen and the whole growth process T1 is rising,Compensation late T4 were significantly higher than T1.Late Wufengyou T025 between T0, T1, T2, T3 treatment with the development of the fertile phase of chlorophyll content decreased,The T4 times the amount of compensation has been maintained at a high level.Rice Ganxin 203 each processing photosynthetic rate showed a downward trend,After the deficit compensation process T3, T4 decline was significantly lower than other treatments.Late Wufengyou T025 nitrogen is not the whole growth period T0,After the deficit without compensation process T2 With the growth of photosynthetic rate of advance downward trend,The deficit after compensation process T3, T4 and growth period of nitrogen application T1, It showed a downward trend after the first rise.At the same deficit after the compensation process photosynthetic rate of super hybrid rice increased significantly,Compensation late T3, T4 or higher than T1.After tillering deficit compensation,Double Cropping Super Hybrid Rice nitrate reductase NR, glutamine synthetase GS activity,(GA3 + IAA + ZR) / ABA, absorption and utilization of nitrogen, nitrogen agronomic efficiency, physiological N use efficiency has improved significantly.Nitrogen stress in tillering, panicle initiation stage to restore nitrogen supply,Root vigor double cropping super hybrid rice dry matter accumulation, nitrogen metabolism activity, photosynthetic rate has been significantly improved, the endogenous hormone balance has been significantly optimized to significantly enhance the ability of nitrogen uptake by rice, nitrogen utilization rate improved significantly.Yield super hybrid rice after the compensation is not significantly higher than the deficit compensation process.While in the case of an equal amount of total nitrogen, rice Wufengyou T025 times the amount of compensation processing plant yield higher than T1.