Effects of Drought Stress on Photosynthetic Characteristics at Different Growth Stages of Sugarcane

Four main sugarcane cultivars (Yuetang 86-368, Yuetang 93-159, Yunyin 3 and ROC 22) in Yunnan were used as experimental materials, the photosynthetic and chlorophyll fluorescence indexes of the four sugarcane varieties at seedling stage, tillering stage, elongating stage were measured and analyzed.And the effects of photosynthetic characteristics on sugarcane at different stages under drought stress condition were compared to find the most sensitive period to drought of sugarcane and looking forward to the theoretical basis of the sugarcane drought resistance production. The results showed that under drought stress condition, the photosynthetic characteristics change of Yunyin 3 at tillering stage was bigger than that at seeding stage and elongating stage, but the biggest changes of both photosynthetic and chlorophyll fluorescence for the rest cultivars at elongating stage. For Yuetang 86-368, Yuetang 93-159 and ROC 22, the biggest impact of the growth period was elongating stage, and the greatest influence on Yunyin 3 was tillering stage.