Effects of Different Salt Doses on Seed Germination in Pepper Varieties

Abstract

In production areas, increasing salinity levels limit seed germination and plant growth. Knowing how pepper seeds respond to specific salt doses is crucial for production. Therefore, this study aimed to determine the effects of different NaCl concentrations (0, 50, 100, and 150 mM) on the seed germination performance of four pepper (Capsicum annuum L.) cultivars (Karaisalı, BT Bursa Yağlık 016, Yalova Çorbacı 12, and Demre). The experiment was conducted under controlled conditions as a completely randomized factorial design with four replications. Germination percentage, mean germination time, germination index, germination rate index, Timson index, and salt tolerance index (STI) were determined; the obtained data were evaluated using principal component analysis (PCA). The research results revealed that increasing NaCl concentrations generally decreased the germination percentage and germination speed. Variations were determined among the cultivars under salt stress; the Demre cultivar stood out with high germination index and germination rate index values across all salt levels. On the other hand, the Karaisalı cultivar did not show a sudden drop in germination performance, even at high NaCl doses. In contrast, the Bursa cultivar showed the lowest performance at all doses, while the Yalova cultivar exhibited a relatively tolerant structure at moderate salinity and a sensitive one at high salinity. The PCA results confirmed that the cultivars clustered into three distinct tolerance groups and that Demre and Karaisalı were high-performing genotypes with low stress loss The results revealed that increasing NaCl concentrations generally decreased the germination percentage and germination speed. Under salt stress, variations were determined among the cultivars; the Demre cultivar stood out with high germination index and germination rate index values across all salt levels. The Karaisalı cultivar did not show a sudden drop in germination performance, even at high NaCl doses. In contrast, the Bursa cultivar showed the lowest performance at all doses, while the Yalova cultivar exhibited a relatively tolerant structure at moderate salinity and a sensitive one at high salinity. The PCA results confirmed that the cultivars clustered into three distinct tolerance groups and that Demre and Karaisalı were high-performing genotypes with low stress loss. In conclusion, the physiological indices and PCA analyses used during the germination period allowed for a reliable determination of salt tolerance in pepper; they demonstrated that the Demre and Karaisalı cultivars are promising genotypes for cultivation and breeding studies in areas with salinity risk.