Field evaluation of salt-alkaline tolerance and trait correlation analysis in different peanut varieties (lines)

To identify high-quality peanut varieties (lines) with tolerance to salt-alkaline stress, 29 peanut varieties (lines) were cultivated over two consecutive years at an experimental site in the Yellow River Delta. Their agronomic characteristics, as well as yield and quality traits, were systematically evaluated. A comprehensive screening approach combining principal component analysis (PCA), membership function analysis, and hierarchical cluster analysis was used to identify superior salt-alkaline-tolerant varieties. The results revealed that the oleic acid to linoleic acid ratio (O/L ratio) and linoleic acid content showed the greatest variation, while fat content, protein content, and shelling percentage exhibited relatively smaller differences. Main stem height and lateral branch length were significantly positively correlated with pod yield and kernel yield, respectively. Oleic acid content was significantly negatively correlated with 100-kernel weight, whereas linoleic acid content showed a significant positive correlation. Peanut yield traits (kernel rate, pod yield, and kernel yield) were closely associated with both agronomic traits (number of fruiting branches, main stem height, lateral branch length) and quality traits (protein content, fat content, oleic acid content, and linoleic acid content). Comprehensive analysis indicated that varieties P16-22, Huayu 9147, Huayu 9141, Huayu 9118, Huayu 9121, Huayu 60, Huayu 9125, and Huayu 9124 performed exceptionally well in saline-alkali soil conditions, whereas Huayu 656, P18-82, P18-43, and P17-18 showed poor adaptability. The former group produced significantly higher pod and kernel yields than the latter. These findings provide valuable genetic resources for breeding salt-alkaline-tolerant peanut varieties and offer useful references for parental selection in future breeding programs.