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Roots as a nutrient and water absorption, synthesis of a variety of physiologically active substances vital organs, the developmental characteristics will directly affect the growth of the shoot. In agricultural soil water supply was severely limited, the role of the root is more prominent. However, due to the special environment for the growth of the root system, the separation of the technical difficulties involved in the study of the roots of far less aboveground depth. Therefore, to further explore the roots of drought tolerance in the adaptive changes under different environmental conditions, will be a water-saving agricultural research direction. In this paper, drought resistance and root characteristics of different rice varieties Morokeran IRAT109, IR62266 and IR1552 as the test material, under greenhouse conditions, nitrogen, potassium, light and water treatments, root adaptability under different environmental conditions the relationship between the change and plant nutrient status, provide a theoretical basis to understand the different environmental factors on the adjustment mechanism of drought resistance in rice. The main results are as follows: 1 with water stress increased, high-nitrogen, high potassium treatment plant leaf water potential were significantly lower than the control. Drought-resistant varieties to water stress showed strong resistance to leaf curl, leaf water potential below the drought-sensitive varieties. In the same leaf curl, the shade leaf water potential is lower than the control. Shade and increasing nitrogen, potassium can ease shoot the extent of injury by drought. 2 under water stress biomass below the normal water treatment. Under drought conditions, with increasing nitrogen rate, drought-sensitive varieties of dry matter weight increase, drought-resistant varieties increased but not significantly. High potassium treatment plant dry matter weight of normal water and water stress difference was not significant. After rehydration, increasing nitrogen fertilizer, potash fertilizer plant biomass has also increased but still below the normal water treatment. Nitrogen deficiency affects plant growth, particularly evident after rehydration. 3 root growth by the effects of moisture and nutrients. Root adaptive changes occurred in different nutrients and moisture conditions. Normal water by nitrogen, potash, and root dry weight increase, but not obvious under water stress. Rehydration, increasing potassium plant root biomass did not increase significantly. Drought-resistant varieties of nitrogen fertilizer is not sensitive to drought-sensitive varieties root dry weight increased with increasing nitrogen. Shade affect plant underground growth, four varieties of root growth is inhibited. Nitrogen fertilizer on root dry matter weight increase, but this effect by water; potash increased root biomass no significant role in promoting. 4 rehydration after drought-resistant varieties of growth rate and dry matter relative growth rate were higher than the drought-sensitive varieties, root growth inhibition rate lower than the drought-sensitive varieties. Rehydration after drought-resistant varieties can quickly restore growth, the accumulation of a large amount of dry matter in a short period of time. Drought-sensitive species ability to withstand drought, poor rehydration ability to restore growth. In addition, by nitrogen fertilizer, potash fertilizer plants absolute biomass increased significantly, but the rate of plant growth, dry matter growth rate higher than the low nitrogen, low potassium treatment and control. High nitrogen, potassium is conducive to root growth, was more effective rehydration. 5 different nitrogen and potassium levels to change the composition and morphology of the root system. Under water stress, high-nitrogen, high potassium roots overall roughness decreases, the root of the surface area and strong life force that increase the proportion of the total root Shirane, improve the ability of roots to absorb nutrients, the plants' ability to adapt to water stress increased. Normal underwater, high-nitrogen, high potassium to
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