Comprehensive analysis of low potassium tolerance traits of black sesame seedlings

<bold>Objective</bold> This study aims to investigate the screening and evaluation indicators of low-potassium（K）tolerance of sesame varieties，thus providing important support for screening out of high K-efficient and breeding of low K tolerant sesame varieties. <bold>Method</bold> Twelve local sesame germplasm resources were used in a hydroponic experiment to compare the differences of plant height（PH），root length（RL），aboveground dry weight（SDW），underground dry weight（RDW），root-shoot ratio （RSR），K content and K accumulation under low K and normal K treatments.The low potassium tolerance coefficient（LPTC）of each index was calculated.Multivariate statistical analysis including principal component analysis（PCA），correlation analysis，cluster analysis and subordinate function was applied to comprehensively assess the low K tolerance of different sesame germplasm resources. <bold>Result</bold> Compared with normal K，the PH，RDW，SDW，plant dry weight（PDW），aboveground K content（SKC），underground K content（RKC），aboveground K accumulation（SKA），root K accumulation（RKA），and plant K accumulation（PKA）of the twelve sesame varieties was significantly reduced under low K treatment and the LPTC of aforementioned indicators was lower （LPTC&lt;1）.Eleven indicators were simplified into three independent comprehensive indicators via PCA，which covered 92.30% of the total information.Based on the <italic>D</italic> value of LPTC calculated by using membership function analysis and clustering analysis，three varieties with low-K tolerance，seven varieties with moderate K sensitive，and two varieties with low-K sensitive were identified. <bold>Conclusion</bold> RKA，SKC，RDW，and RL could be critical indicators for identifying the low K tolerance of sesame.Duchang Hei，Jinkou Hei，and WZM6 are low-potassium-tolerant varieties；Zhongzhi 9 and Ganzhi 14 are low-potassium-sensitive varieties.