Abstract: Phosphorus is one of the indispensable nutrients for plant growth and development, orthophosphate (P) content in the soil is particularly rich, but due to the fixation of the soil, the effective phosphorus content that can be absorbed and utilized by plants is not high, and improving the absorption and utilization capacity of plants to soil phosphorus, or optimizing the application of phosphate fertilizer, has become an urgent problem need to be solved. The content of phosphite (PH) in soil is second only after orthophosphate, and it has the characteristics of higher solubility, two-way transport between plant xylem and phloem, and it is not easy to be fixed by soil, but the research on phosphite as phosphate fertilizer to replace orthophosphate fertilizer and phosphite-tolerant crop varieties breeding has rarely been reported. Therefore, in this study, five introduced potato (Solanum tuberosum) genotypes and one commercial variety Qingshu No. 9 (QS9) were selected as test materials, and the seedings weere directly planted into the test field after domestication and refining, and normal phosphate fertilizer treatment and phosphite substitution treatment were set up to determine the phenotype, photosynthesis, dry matter and other indicators of different materials. Moreover, the phosphite tolerance coefficient (PTC) of each indicator was used as the measurement basis. Comprehensive evaluation of the PH resistance of different potato materials was conducted based on principal component analysis and other methods. The resulted showed that the six potato materials could be divided into three types: highly phosphite-tolerant (C115, D13), weakly phosphite-tolerant (C20, C31, QS9) and phosphite-sensitive (C80). This study evaluated the tolerance of different potato materials to phosphite, aiming to provide scientific basis for the selection of phosphite-tolerant varieties and the development of new phosphite fertilizers.

Key words: potato, phosphite tolerance coefficient, principal component analysis, membership function analysis, cluster analysis, comprehensive evaluation