Distribution Characteristics of Photosynthetic Products of Nanjing Series of Super Rice During Filling Stage
[Objective]The aim of this study was to investigate the characteristics of the transport and distribution of photosynthetic products and related gene expression levels during the grain filling period of the Nanjing series of super rice,as well as the differences with the control varieties,to summarize the physiological advantages of high-yield in the Nanjing series super rice,so as to provide the theoretical basis for the development of high-quality and high-yield japonica rice.[Method]Nanjing 5718,Nanjingjinggu,Nanjing 3908,and Nanjing 5055 were used as the research materials,with Huaidao 5 as the control.The photosynthetic rate of flag leaves,distribution and transportation of aboveground dry matter,and expression levels of photosynthetic product transport related genes at different stages of flag leaf and seed development were measured every 7 days during the booting stage,flowering stage,and flowering to maturity stage,and yield differences were statistically analyzed too.[Result]The yield and 1000-grain weight of the Nanjing series of super rice were higher than those of Huaidao 5,and its net photosynthetic rate of flag leaves was significantly higher than that in Huaidao 5 during the booting stage and 28 days after flowering.In terms of photosynthetic product transport,the stem and leaf dry weight,leaf output,output rate,and transport rate of the Nanjing series super rice were significantly higher than those of Huaidao 5 after flowering,with Nanjing 5718 having the highest leaf output and output rate.The expression of genes related to starch degradation and carbohydrate metabolism(OsSPS1,OsSUT2,and OsGWD1)in the flag leaves of Nanjing 5718 was initiated earlier than other varieties,and the highest expression level was also higher than other varieties.The SWEET gene in grains played an important role in early sucrose transport during grain filling,while the OsPK3,OsSUT1,and OsSUT2 genes played an important role in sugar transport and unloading during the middle and late filling stages.The OsAGPL2 and OsDPE1 genes played the important roles in starch synthesis during the middle and late filling stages.The expression levels of genes related to starch synthesis and sugar transport in grains of Nanjing 5718,Nanjingjinggu,and Nanjing 3908 were significantly higher than those of Huaidao 5 at different stages.[Conclusion]The higher yield of the Nanjing series of super rice was mainly characterized by the following characteristics in terms of material transport:a large accumulation of dry matter in stem,leaf and panicles,and a high transport rate of leaf and stem dry matter;the high expression levels of genes related to sucrose metabolism and transport in leaves were beneficial for the synthesis,loading,and transport of sucrose at the source end;the high expression levels of genes related to sucrose transport and starch synthesis in grains were conducive to the unloading of sucrose at the storage end and the synthesis of starch in grains.
super ricephotosynthetic productsgene expressionproducts distributionsucrose transporthigh yield breeding
国家科技期刊平台
NSTL
万方数据
