Study On Screening And Mechanisms Of High Potassium Efficient Cotton Genotype

Cotton is one of important crash-crops in our country. There is great influence to cotton yields and fiber traits under K deficiency. However, K resources are very shortage in China. It is one of a way to resolve there problems to screen high K-efficiency genotypes. 47 cotton cultivars has been collected from Xinjiang. Nutrient solution culture, pot experiment and chemical analysis were used to compare the difference of potassium efficiency among cotton genotypes. The potassium absorption, utilization characteristics and roots' physiological and biological chemistry property under the potassium stress were also been studied to get some ways of different potassium efficiency of various cotton genotypes.The main results of study are as followed:1. In seedling stage screening experiment, among 47 cotton genotypes had significantly difference, so we got potassium-efficiency genotype XINLUZAO6, XINLUZHONG15, XINHAI16, and potassium-inefficiency genotype XINLUZAO10 and SHIK7 in the experiment.2. In the pot experiment without potassium application, the high potassium efficiency genotype grows well-balanced in without potassium application. There was significant difference among the absorption and utilization ability of different genotypes. The XINLUZHONG15 was the best genotype in biomass yield, potassium absorption and potassium accumulation, and XINLUZAO10 was the least.3. In the pot experiment without potassium application. There was significant difference among potassium use index of different genotypes. The potassium-efficient genotypes XINLUZHONG15 and XINHAI16 can absorb more potassium from soil and had the most potassium use index, so it's high efficiency in potassium absorption and utilization.4. The potassium accumulation quantity is higher than lacks potassium in difference cotton genotypes. Regardless of is the high potassium-efficiency genotype, the low potassium-efficiency genotype, potassium accumulation had significant difference in various times. The earlier period cotton genotype' CV% had remarkable difference in the potassium accumulation. It is may take the ideal screening time.5. In the pot experiment without potassium application, K-deficiency symptoms appeared after among different cotton genotypes, but high potassium-efficiency cotton symptoms were weak. The volume, roots fresh weight, roots activity and pH of potassium-efficiency cotton XINLUZHONG15 were significantly higher than those of potassium-inefficiency genotype, Meanwhile the root' active absorb area and overall absorb area had no significant difference among genotypes.6. There were differences in the absorption and distribution of other nutrients among different cotton genotypes. The accumulation of N, P were raised while that absorption was reduced when K was applied. The Na absorption of genotypes was greater than those of inefficient K genotypes on without potassium application. The XINHAI16 was the best genotype in Na absorption. This shows different cotton genotypes have Na to replace K process.