Identification And Screening Of Low Potassium Tolerant Cottons With Fusarium And Verticillium Wilts Resistance

A vermiculite culture experiment and solution irrigating were carried out simultaneously to approach the screening index for low potassium tolerant cotton varieties in preliminary experiment 6 genotypes cottons had been adopted in present research work for investigating phant height, the total proportion of leaves,the shoot dry weight, the root dry weight, the total dry weight,chlorophyll content, k utilization efficiency of cotton seedings under different potassium supply in the nutrients solution .The differences of each indexes for low potassium tolerant cotton varieties were confirmed and a method was founded to screen low k tolerant cotton varieties at seedling stage.88cotton varieties with Fusarium and Verticillium wilts resistance were screened in this method for low k tolerant.The results were as followed:1. The differences of cotton varieties in potassium nutrition were significant. phant height,.The seedling dry weight, the root dry weight, the total dry weight, chlorophyll content and k utilization efficiency were close related with k nutrition, the differences of them among different k concentrations and cotton varieties were significant so that these indexes were confirmed to screen cotton varieties with Fusarium and Verticillium wilts resistance at seedling stage, but differences of the total proportion of leaves was not significant.2. The correlation analysis showed that a significant relationship existed between relative total dry weight, phant height,shoot dry weight, KUE at seedling stage, chlorophyll content,. The relative shoot dry weight was regarded as a selection index of the response to k stress.3. According to the established screening index.Cotton tested 88 Fusarium and Verticillium wilts resistance varieties can be divided into low potassium genotype (21 Varieties) , intermediate (58 Varieties) and low potassium genotype (6 Varieties) three categories of non-resistance.The cotton varieties 86-1, Shannmianll and Zhongmiansuo20 were high KUE genotypes, Jinmian8, Yu2067, Liuzhuang1, Shan8092, Kangbingdongtingmian and Chuanbei2 were low KUE genotypes.4. The three low potassium-resistant including 86-1,Shannmian 11,Zhongmiansuo20 and 3 low potassium-sensitive varieties containing Jinmian8, Yu2067 and Liuzhuang1 were screened respectively in low potassium stress. The result showed that low potassium-resistant varieties were generally higher than non-resistant varieties potassium.in SOD,POD,CAT activity under the low potassium conditions.