TURKISH JOURNAL OF AGRICULTURE AND FORESTRY, cilt.48, sa.2, ss.183-198, 2024 (SCI-Expanded)
Limited knowledge exists regarding the fatty acid profiles of spinach (Spinacia oleracea L.) seeds and their correlation with germination. This study aims to address this gap by thoroughly investigating these profiles and their relationship with seed germination. Therefore, the objectives include assessing how different temperatures influence seed germination in spinach cultivars, identifying tolerant cultivar(s) to temperature stress during germination, and exploring the relationship between fatty acid profiles and seed germination under varying temperature conditions. Nine spinach cultivars (‘Matador-1, 2, and 3’, ‘Ranchero F1’, ‘Aras F1’, ‘El Tajin’, ‘El Real’, ‘Catrina F1’ and ‘Poyraz F1’) were used as seed material. The simple correlation test, stepwise multiple regression test, and principal component analyses (PCA) were used to determine the relationships. The fatty acid contents were significantly different among cultivars’ seed samples. C18:2n-6, C18:1n-9, C16:0, and C18:0 were sequentially the highest in concentration followed by C20:1 at less than 3% and the other fatty acids at an even lower content (< 1%) in spinach cultivars. These analyses revealed that the optimal temperature for spinach seed germination is 20 °C. Above 20 oC, germination percentages decreased, with a sharp stop at 35 oC. 'Catrina F1' demonstrated notable heat tolerance, with a 62.04% germination rate at 32 °C and 9.10% at 35 °C, indicating its potential as a valuable heat-tolerant cultivar for spinach breeding programs. C17:1, C18:1n9, and monounsaturated fatty acids (MUFA) displayed negative correlations with germination percentage, while positive correlations were observed between C18:3n-6, C20:1n9, and germination percentage at 30 °C and 32 °C. Based on the results of simple correlation tests, stepwise multiple regression tests, and PCA, it has been revealed that C16:1n7, C17:1, C18:1n9, C18:2n6, C18:3n-6, C20:1n9, C22:0, MUFA, and n-6 PUFA have a great potential to predict the germination capacity of spinach seeds under stress temperatures.