Effect of Nitrogen on Root Vigor and Growth in DifferentGenotypes of Wheat under Drought Stress
The purposes of this study was to investigate the effects of water and N coupling on root vigor and uptake of nitrogen in wheat.Two different cultivars of wheat Xinong 979 and 2036 were planted in Hoagland nutrient solutions.Three treatments of different N levels,low N,normal N and high N and three water regimes,well-watered,moderate drying and severe drying were conducted.The results showed that there was a significant interaction between water regimes and N supply.Severe water stress could decrease the biomass,total absorbing surface,activity absorbing surface,root vigor,nitrogen content and nitrogen accumulation in wheat.Nitrogen deficiency increased the root length and root/shoot,but decreased the biomass,total absorbing surface,activity absorbing surface,activity/total absorbing surface,root vigor,nitrogen content and nitrogen accumulation significantly.The root total absorbing surface,activity absorbing surface and root vigor of Xinong 979 with high N were increased significantly than that of low N and normal N,which are 11%,14%,27% higher than those of 2036,respectively at high N level.Root N accumulation and shoot N accumulation in Xinong 979 had no significant difference between normal N and high N levels.And the plant N accumulation of Xinong 979 was 13% to 62% higher than that of 2036 at normal N level.Correlation analysis showed that activity absorbing surface and root vigor were positively correlated with plant N accumulation(P<0.01),while there was significant negative correlation between activity absorbing surface,root vigor and root/shoot(P<0.01).A negative correlation was observed between root/shoot and plant N accumulation(P<0.01).The increase of nitrogen supply can improve the absorbing surface and root vigor of Xinong 979 effectively,but excessive nitrogen supply was not conductive to the root growth of 2036.These results suggested that the root vigor and growth of wheat with different genotypes respond differently to water and nitrogen coupling.Optimal regulations of water and N supply are beneficial to the formation of good root morphology and increase root vigor,therefore leading to the enhanced ability of absorbing moisture and nutrients.
NETL
NSTL
万方数据
维普
