Wang Xiaoru, Dong Helin, Li Yongqi, Li Pengcheng, Liu Jingran, Liu Aizhong, Sun Miao, Zhao Xinhua, Li Yabing, Zhang Siping
Hydroponics were used to explore the capacity of different cotton varieties to absorb potassium. Six cotton varieties were used to study the effect of different morphological and physiological characteristics on K uptake efficiency and K+ absorption kinetics parameters. The results showed that under low potassium stress, varieties such as CCRI 64, which had high K uptake efficiency, had the largest root dry weight, root volume, active uptake area, active specific surface area, and the strongest root vigor. The high K uptake efficiency variety CCRI 35 also had larger root dry weight, long and fine roots, the largest total root absorption area and total specific surface area, stronger root vigor, the highest K+ maximum absorption rate (Imax), and lower critical concentration(Cmin). CCRI 35 might, therefore, be tolerant of low K stress. Conversely, the K inefficient varieties Zhongzhimian No.2 and CCRI 50 had poor root morphology indicators, weaker root vigor, and smaller K+ maximum absorption rate. The research will not only help to clarify the reasons for resisting low potassium stress among cotton varieties but will also evaluate the adaptability of cotton varieties to low K.
