Effects Of Cultivation Treatments On Yield And Quality Of Super Rice

Rice has a wide planting area in China and is the staple food of people.Rice yield is related to China's food security.With the improvement of people's living standards,everyone's requirements for rice quality are getting higher and higher.Super rice has high-yield characteristics.Although the yield under existing common cultivation conditions has greatly increased,the fertilizer and water use efficiency is low,causing waste of resources and environmental pollution.At the same time,the quality of rice has also deteriorated sharply,affecting people's consumption and demand.To clarify the mechanism of different rice cultivation methods for high-yield,high-efficiency and high-quality production of super rice has become the key to solving the above problems.Therefore,in this study,two super rice varieties,Youyou 2640 and Wuyunjing 24,were used as the research objects,and the cultivation methods used by local farmers were compared.A nitrogen blank area,local routine,and Nitrogen,densification and nitrogen reduction,precision irrigation,increased application of cake fertilizer,deep-turn cultivation,application of silicon and zinc fertilizer,etc.Based on yield,quality and starch,this paper focuses on the growth and development of the two super rice varieties.,Nitrogen absorption and transport,rice quality,key enzymes for starch synthesis,starch fine structure,starch physicochemical properties,and endogenous hormone content in grains,in order to clarify the high-yield,high-efficiency and high-quality cultivation methods of super rice And its physiological mechanisms.The main findings are as follows1.Rice yield,population growth and development characteristics,and nitrogen fertilizer use efficiency indicatorsThe grain yield of Yongyou 2640 under IDRN,PI,ACF,DP and ASZF was 11.26 t hm-2?12.29 t hm-2?12.73 t hm-2?13.46 t hm-2 and 14.89 t hm-2,respectively,and increased by 1.30%,10.03%,16.35%,20.36%and 29.59%respectively,compared with that under the LFP(control).The grain yield of Wuyunjing 24 under IDRN,PI,ACF,DP and ASZF was 10.06 t hm-2?10.81 t hm-2?11.60 t hm-2?12.00 t hm-2 and 12.95 t hm-2,respectively,and increased by 5.67%?13.55%?21.48%?26.05%and 36.03%,respectively,compared with that under the control.Compared with the control(LFP),IDRN,PI,ACF,DP and ASZF significantly increased the percentage of the productive tillers by 7.42%-14.83%,dry matter by 3.11%-24.32%,the efficient LAI by 3.44%-9.37%,the high efficient LAI by 2.78%-8.93%after heading,for Yongyou 2640.For Wuyunjing 24,IDRN,PI,ACF,DP and ASZF significantly increased the percentage of the productive tillers by3.97%-11.68%,dry matter weight by 3.54%-24.83%after heading,efficient LAI by 3.55%-6.58%,high efficient LAI by 3.92%-9.23%after heading.Compared with the control,IDRN,PI,ACF,DP and ASZF can significantly increase the nitrogen uptake and nitrogen use efficiency of plants such as the radio of AE,PE,RE,PFP.However,in terms of IE,Youyoug 2640 and Wuyunjing 24 decreased by 6.30%and 2.74%,respectively,compared with the control.The results indicate that population quality can be improved,source-sink relationship can be optimized,and consequently,grain yield can be increased through the improvement in cultivation practices,but excessive increase fertilizer application will reduce the nitrogen yield increase efficiency of plants.2.Cultivation treatments improve rice qualityThe combination of cultivation techniques,such as reducing N rate during early vegetative stage,alternate wetting and moderate soil drying,and organic fertilizer application can significantly increase rice quality.In terms of appearance and processing quality compared with control,RN,IDRN,PI,ACF,DP and ASZF have significantly increased the brown rice rate,polished rice rate and the chalky area,chalky grain rate,and chalkiness all significantly decreased.In terms of cooking and eating quality,compared with control the protein content of the two super rice was significantly decreased under RN,IDRN,PI,ACF,DP and ASZF.At the same time,the globulin decreased by 0.78%-2.21%,the prolamin decreased by 3.96%-6.63%,the gluten decreased by 6.21%-9.69%,and the albumin increased by 0.43%-3.00%for Yongyou 2640.For Wuyunjing 24 the globulin decreased by 3.37%-4.61%,the prolamin decreased by 4.91%-7.08%,the gluten decreased by 5.79%-10.01%,and the albumin increased by 1.30%-2.61%,cultivation methods increase the content of high-quality taste protein.Compared with the control,the gel consistency of the above 6 cultivation methods was significantly improved.For Yongyou 2640,the average glue consistency is 67.80mm,an increase of 1.3%,for Wuyunjing 24 the average glue consistency is 70.99mm,an increase of 4.08%,respectively.The above research shows that the improvement of cultivation treatments can significantly improve the quality of rice and achieve the goal of high-quality rice production.3.The influence of cultivation treatments on the fine structure and physicochemical properties of starch and its regulating mechanismDuring the synthesis of starch from grains,with the cultivation treatments of RN,IDRN,PI,ACF,DP and ASZF can change the key enzyme activity of starch synthesis and the endogenous hormone content of grains.The changes of these enzyme activities and endogenous hormone content make rice grains synthesize more starch particles with large volume and large surface area.At the same time,when these starches form a molecular structure under those cultivation treatments,the starch molecules have a larger hydrodynamic radius,the debranched chains of amylopectin have a smaller degree of polymerization,the content of short and medium chains increases and the content of long chains decreases.These changes in the fine structure of starch change the physical and chemical properties of starch.The crystalline region of starch becomes smaller and the amorphous region becomes larger.The external short-range disordered structure increases,the ordered structure decreases,and the crystallinity and order of starch The decrease causes the starch to require less gelatinization enthalpy and lower gelatinization temperature while gelatinizing,while having greater viscosity and greater breakdown and setback.Compared with the control(LFP),RN,IDRN,PI,ACF,DP and ASZF significantly increased the percentage of the breakdown by 2.88%-26.52%,increased the percentage of the setback by 6.47%-12.82%,gelatinization enthalpy by 1.58%-7.88%for Yongyou 2640.For Wuyunjing 24,these cultivation treatments increased the percentage of the breakdown by 26.18%-53.02%,increased the percentage of the setback by 1.90%-25.26%,gelatinization enthalpy by 1.58%-7.88%.The above research shows that the improvement of cultivation treatments has changed the enzyme activity and hormone content,so that starch has larger starch molecules and shorter amylopectin chain lengths when the structure is formed.Structural changes cause changes in the physicochemical properties of starch,including relatively low crystallinity,high disorder,and large swelling and solubility eventually make the starch gelatinization enthalpy value lower and the viscosity greater,and finally make the rice and starch quality better.