Effects of exogenous brassinolide and different water treatments on growth physiology,yield,and nitrogen use of rice
In 2022,with'Xudao 3'as the material,two water treatments of normal irrigation(soil water po-tential was 0 kPa),moderate water stress(soil water potential was-30 kPa)and four different concentrations of exogenous brassinolide(BR,0,0.1,1.0,5.0 μmol·L-1)were set up during the growth period.The effects of different water treatments and brassinolide coupling on root growth,root nitrogen metabolism enzyme activity,aboveground growth and nitrogen utilization were studied.Compared with normal irrigation during the whole growth stage,moderate water stress significantly reduced root total length,root surface area,root volume,active root total absorption area,total root absorption area,shoot dry mass,plant height,tiller numbers and net photosynthetic rate of rice by 21.8％,20.6％,12.9％,13.9％,13.4％,26.3％,13.8％,17.7％and 13.1％,respectively.The average diameter of root,root activity and root-shoot ratio were increased by 8.0％,28.6％and 26.6％respectively.With the increase of exogenous brassinolide concentration,root total length,root surface area,root average diame-ter,root volume,root active absorption area,root total absorption area,nitrate reductase activity,glutamine syn-thetase activity,shoot dry mass,plant height,tiller numbers,net photosynthetic rate and chlorophyll content all showed a trend of first increasing and then decreasing.The maximum value was reached under 0.1 μmol·L-1(B1)treatment.Root total length,root surface area,root volume,root total absorption area,root active absorption area,glutamine synthetase activity,shoot dry mass,plant height,tiller numbers,net photosynthetic rate and chlorophyll content were significantly positively correlated with yield and nitrogen fertilizer utilization.In conclusion,the inter-action of normal irrigation and B1 treatment during the growth period was conducive to the increase of yield,which was the best coupled operation mode of water treatment and brassinolide in this experiment.
brassinosteroids(BR)water treatmentriceroot morphology and physiologyabove-ground growthnitrogen utilization
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维普
