Abstract:

Drought during the grain filling period can seriously affect the later growth and development of foxtail millet plants,as well as the morphogenesis,yield,and quality of grains.To analyze the effects of drought during the grain filling period on the later growth and development of foxtail millet,as well as the morphogenesis of grains,and to provide a theoretical research basis for the molecular mechanism of foxtail millet starch regulation in response to drought stress,it investigated the effects of different degrees of drought during the grain filling period on the agronomic and grain quality traits of foxtail millet using Jingu 21 as the material.Simultaneously,Real-time Quantitative PCR was used to analyze the response of key genes SiAGPase1(Glucose pyrophosphorylase)and SiSSS1(Starch synthase)to drought during starch synthesis.The results showed that drought had significant effects on fresh weight per plant,fresh weight per root,fresh weight per panicle,panicle weight,grain weight per spike,grain weight per thousand grains,main stem diameter,subpanicle internode length,chlorophyll content,seed setting rate,spike code density and other agronomic characters.The more severe the stress,the greater the degree of reduction.The analysis of grain composition showed that drought can reduce the content of fat,crude protein,peak viscosity and final viscosity.The more severe the stress,the greater the reduction degree.Gene expression analysis showed that the expression levels of SiAGPase1 and SiSSS1 changed sharply during the grain filling period under drought stress.The results revealed that SiAGPase1 and SiSSS1 played an active role in regulating the balance between starch decomposition and starch accumulation in grains under drought stress in order to adapt to plant response to drought stress.

Key words: Foxtail millet, Filling, Drought, Starch synthesis

CLC Number: 

• S515粟(谷子、小米)