土壤缺钾严重降低了我国马铃薯(Solanum tuberosum)的产量。而不同品种马铃薯对低钾的响应差异较大。因此, 采用耐低钾马铃薯品种可通过提高钾素利用效率减少钾肥施用量, 成为我国农业可持续发展和绿色发展的重要途径。该研究对30个马铃薯品种在正常钾处理(202.5 kg∙hm^-2 K₂O)和低钾处理(0 kg∙hm^-2 K₂O)下的17个指标进行测定, 并对9个代表性指标, 包括叶面积指数、根冠比、茎叶干质量、根干质量、单株产量、单株大薯产量、单株小薯产量、块茎干质量和块茎钾积累量进行后续分析。结果表明, 在低钾条件下, 各项指标均有不同程度的下降。主成分分析表明, 这9个指标可转换为4个独立的综合指标, 累计贡献率达87.1%。根据综合评价值(D值)和聚类分析, 将30个品种分为6类, 其中第1类为高度耐低钾品种, 包括Lucinda、Favorita、Kexin1、Xisen6、Xingjia2、Helan15和Chuanyin2, 第2类为中度耐低钾品种, 包括Longshu20、Dingshu3、Jizhang12(W)、Jiuen1、Longshu19和Jizhang12(Y)。此外还建立了耐低钾性评价回归模型Y= -0.595+0.247X₅+0.155X₄+0.138X₃+0.167X₈+0.088X₁+0.081X₆+0.097X₉+0.053X₂ (R²=0.999, P=0.000), 利用回归方程对30个品种的估计精度均在90%以上。在低钾条件下, 可利用单株产量、根干质量、茎叶干质量、块茎干质量、叶面积指数、单株大薯产量、块茎钾积累量和根冠比快速鉴定耐低钾马铃薯品种。

Soil potassium deficiency has severely reduced the potato field production in China. Fortunately, different potato varieties respond to low-potassium conditions very differently. Therefore, the utilization of potato varieties with low-potassium tolerance is an important approach to reduce potassium application by increasing potassium utilization efficiency, thus promoting the sustainability and the green development of agriculture in China. In this study, 17 biological features of 30 potato varieties were examined under normal potassium (202.5 kg∙hm^-2 K₂O) and low potassium conditions (0 kg∙hm^-2 K₂O), and nine representative features, including leaf area index, root-shoot ratio, shoot dry mass, root dry mass, tuber yield per plant, large tuber yield per plant, small tuber yield per plant, tuber dry mass, and tuber potassium accumulation were selected for subsequent analysis. The results showed that all feature values went down under the low potassium condition. Principal component analysis revealed that the nine features can be transformed into 4 independent comprehensive components, with a cumulative contributive rate of 87.1%. According to the comprehensive evaluation value (D value) and cluster analysis, the 30 varieties can be divided into 6 categories, including seven high tolerant varieties to low potassium: Lucinda, Favorita, Kexin1, Xisen6, Xingjia2, Helan15 and Chuanyin2, and six varieties with moderate tolerance to low potassium: Longshu20, Dingshu3, Jizhang12(W), Jiuen1, Longshu19, Jizhang12(Y). Furthermore, we developed a regression model Y=-0.595+0.247X₅+0.155X₄+0.138X₃+0.167X₈+0.088X₁+0.081X₆+0.097X₉+ 0.053X₂ (R²=0.999, P=0.000) to distinguish the 30 varieties from each other with an accuracy above 90%. In summary, under low potassium condition, several features, including tuber yield per plant, root dry mass, shoot dry mass, tuber dry mass, leaf area index, large tuber yield per plant, tuber potassium accumulation and root-shoot ratio can be used to rapidly identify low potassium tolerant varieties.