灌浆期高温对水稻不同粒位籽粒品质的影响OA北大核心CSTPCD

High temperature during grain filling stage can lead to the decline of rice quality,and the grain quality varies with variety and spikelet position.In this study,four indica rice varieties were used as the research objects,and the split-plot design was adopted with two sowing date treatments(S1 and S2)in the main plot and four indica rice varieties(V1,V2,V3,V4)in the subplot,to study the effects of different tem-perature at filling stage on quality of rice grain at different grain positions caused by staged sowing under field conditions.The results showed that high temperature at filling stage under S1 sowing date reduced the whole rice rate,dissipation value and peak time,and increased the chalky grain rate,globin content,peak viscosi-ty,disintegration value and gelatinization temperature of the four rice varieties.Under the suitable temperature condition at grain filling stage of S2 treatment,the rice milling rate and whole rice milling rate of grains from the upper part of panicle in each variety were significantly higher than those from the lower part.Under the high temperature condition at grain filling stage of S1 treatment,the chalky grain rate,chalkines,peak viscosi-ty and disintegration value of grains from the upper part of panicle in each variety were higher than those from the lower part,and most of which were different significantly,but the dissipation value and peak time were significantly lower than those from the lower part.There was no significant correlation between gluten content,rice milling rate and characteristic values of RVA spectrum.The correlations between chalky grain rate,chalk-iness,albumin,globulin and each characteristic value of RVA spectrum were reverse with that between amy-lose and each characteristic value of RVA spectrum,indicating that the contents of amylose and protein com-ponents directly affected the gelatinization characteristics and eating quality of rice.In summary,high tempera-ture at filling stage of S1 treatment reduced the rice milling rate and increased the characteristics such as chalk-iness rate,peak viscosity and gelatinization temperature,which had significant effects on the upper,middle and lower grains,and the effect was more obvious on the grain quality of upper panicle.