Response of Flue-Cured Tobacco Seedling Growth at Different Nitrogen Levels

In this experiment, a flue- cured tobacco variety K326 was used as material by sand culture and nutrient solution watering to study the response of flue-cured tobacco to different nitrogen levels at the vegetative growth stage. The results showed that the accumulation of dry matter of flue-cured tobacco increased with N concentration increasing, which was conducive to the growth of aboveground parts and reduced the root- shoot ratio; the growth of roots and stems was promoted under slight N deficiency, root growth was inhibited under excessive N levels; the chlorophyll content decreased at N deficiency level, the chlorophyll content increased under adequate supply of N; nitrate reductase activity and root activity rose with N concentration increasing; and the degree of oxidation of the membrane lipid was related to N supply level, the MDA content was massively accumulated under severe N deficiency, and the high N supply reduced the level of membrane lipid oxidation.