施氮量对优质稻“福香占”光合特性、产量及品质的影响

Effects of Nitrogen Rate on Photosynthesis,Yield and Grain Quality of Superior Quality Rice“Fuxiangzhan”

【目的】烟稻轮作生产模式可以有效改善土壤生态,促进农业增效、农民增收。氮肥是影响水稻生长发育的关键因素,为明确优质稻“福香占”在福建烟后稻区的最佳氮肥施用量,充分发挥其优质、高产特性,【方法】本研究设置CK(0)、N1(51.75)、N2(103.5)、N3(155.25)、N4(207 kg/hm^(2))5个氮肥(以纯氮计)水平,在大田环境下,分析“福香占”光合特性、田间产量及其构成因素、稻米品质、香味等方面的变化。【结果】随施氮量增加,“福香占”生育期逐渐延长,叶片SPAD值、净光合速率、叶绿体大小、叶片中蔗糖和淀粉含量均上升,N3或者N4达到最高。两年穗总粒数和田间产量均是N2最高,结实率、千粒重随施氮量增加而降低。稻米加工品质N2处理表现最好,外观品质和食味品质受氮肥水平影响不显著。蛋白质含量随氮肥量升高而增加,峰值黏度、热浆黏度、最终黏度、崩解值均随氮肥量增加而降低,消减值升高。N2处理糙米香味物质2-乙酰-1-吡咯啉(2-AP)的含量最高。【结论】氮肥处理促进了“福香占”的光合作用,但过量氮肥使得植株贪青迟熟,结实率和产量下降。施氮量为103.5 kg/hm^(2)(N2)时,“福香占”高产和优质协调,香味物质积累多。本研究为“福香占”进一步在福建烟后稻区推广应用及优质稻产业高质量发展奠定了基础。

【Objcetive】Tobacco-rice rotation can effectively improve soil ecology,promote agricultural efficiency and increase farmers'income.Nitrogen fertilizer is a key factor affecting the growth and development of rice.In order to determine the optimal nitrogen application rate and to give full play to the high quality and high yield potential of the superior quality rice“Fuxiangzhan”in the tobacco-rice rotation areas of Fujian Province,【Method】Five nitrogen rates,(CK:0,N1:51.75,N2:103.5,N3:155.25,and N4:207 kg/hm^(2) by nitrogen)were set to analyze effects on photosynthetic characteristics,grain yield and its components,grain quality and aroma of brown rice under the field environment.【Result】The results showed with the increase of nitrogen application rate,the growth duration of“Fuxiangzhan”was gradually prolonged,chlorophyll SPAD value,net photosynthetic rate,chloroplast size,sucrose and starch contents in flag leaves were increased,and all the parameters mentioned above reached the highest value in N3 or N4 treatment.The grain number per panicle and grain yield maximized in N2 treatment,but the seed setting rate and 1000-grain weight decreased with the increase of nitrogen application rate.For the processing quality of grain,it performed best in N2 treatment.The appearance quality and eating quality were not significantly affected by nitrogen rates.The total protein contents increased with the increase of nitrogen rates.For RVA profile,the peak viscosity,hot viscosity,final paste viscosity and breakdown value decreased,while the setback viscosity value increased.The content of 2-acetyl-1-pyrroline(2-AP)in brown rice under N2 treatment was the highest.【Conclusion】The results showed nitrogen treatment promoted the photosynthesis of“Fuxiangzan”,but excessive nitrogen made plants late-ripening,reduced seed setting rate and yielding.At the nitrogen application rate of N2(103.5 kg/hm^(2)),we struck a balance between high yield and good quality with the most aroma substances accumulated.This study laid a foundation for the further popularization and application of“Fuxiangzhan”in production and the development of high-quality rice industry in the tobacco-rice rotation areas of Fujian Province.