Effects of Water Stress on Growth and Development in Cotton （Gossypium hirsutum L.）

【Objective】 The aim was to study the effect of water stress on growth and development in different cotton varieties,selected drought-resistant germplasm resources. It can help providing reference for drought-resistant breed selection. 【Method】 Eleven cotton varieties（strains） were used to investigate under normal irrigation（3,600 m³/hm²） and water stress（1,800 m³/hm²） condition,which for exploring the diversity of growth progress,morphological indexes,dry matter accumulation,antioxidant enzyme activity change and yield components. 【Result】 Water stress accelerated the growth progress of cotton,growth stages reduced 1-5 days of eleven cotton varieties（strains）. The lack of water inhibited the growth of cotton plant,which also resulted in a decrease of fruit branch and bud number. Under the water stress condition,dry matter accumulation per plant reduced 0.70 g,5.68 g and 2.18 g in seedling stage,boll forming stage and boll opening stage. At the same time,the number of effective bolls per plant and the single boll weight decreased by 0.89 and 0.23 g. The reduction of seed cotton yield ranged from 1.93% to 37.14%. Antioxidant enzyme activity changed of eleven cotton varieties（strains）,the activity of SOD,POD,CAT all went up of three cotton varieties（strains） Under water stress. 【Conclusion】 Considered all experimental varieties performance of growth progress,agronomic characters,dry matter accumulation,antioxidant enzyme activity change and yield characters,we found that the Growth and Development of number 9 and 2 were better under the water stress condition. And its yield reduction was insignificant. Cotton varieties 9 and 2 had the better drought resistance under the test condition.