Differential Analysis of Nitrogen Utilization and Tolerance to Low Nitrogen Level Between Flue-cured Tobacco Cultivars(Genotypes)

Nitrogen utilization and tolerance to low nitrogen level were investigated on flue-cured tobacco cv.Yuyan 5,Yuyan 6,Yuyan 7 and Zhongyan 100.The results showed that there were significant differences of nitrogen utilization and tolerance to low nitrogen level between different tobacco genotypes,and the maximum difference was observed under low nitrogen level.The leaf weight per plant,response index to nitrogen,dry matter accumulation,nitrogen accumulation and nitrogen utilization of cv.Yuyan 5 were the highest,while those of cv.Zhongyan 100 the lowest;which indicated that cv.Yuyan 5 possessed a strong ability of nitrogen uptake and accumulation,it was a cultivar with higher tolerance to low nitrogen level and higher nitrogen utilization;however,Zhongyan 100 was a cultivar with lower nitrogen utilization and susceptible to low nitrogen level.