Priming enhances germination and reserve mobilisation in quinoa seeds under salt stress

Abstract

Salinity is a significant challenge that limits agricultural production, making it essential to adopt salt-tolerant crops, such as quinoa, as a solution. Salinity can still impact quinoa’s performance during the germination stage. This study evaluated seven priming agents (zinc sulfate “Zs”, sodium metasilicate “Si”, and plant extracts from Peganum harmala “Ph”, Suaeda vermiculata “Su”, Atriplex halimus “Ah”, Fucus spiralis “Fs” and rosemary hydrolat “Rh”) on enhancing germination tolerance of three quinoa varieties (‘Titicaca’, ‘ICBA‐Q5’ and ‘Puno’) under 300 and 400 mM of NaCl stress. Additionally, seed protein and sugar reserves were assessed for the ‘Puno’ variety at 300 mM NaCl. Priming significantly increased the germination percentage, notably for ‘ICBA‐Q5’ with Zs (95%) and Rh (86%) compared to unprimed seeds (56%) at 300 mM. Priming treatments substantially reduced mean germination time, particularly in ‘Titicaca’ under 400 mM NaCl, most effectively with Ah (3.34 days) against the control (3.61 days). However, protein and sugar concentrations markedly declined during germination under salinity stress, especially compared to unprimed seeds, indicating an enhanced mobilisation process in the seed reserves. ‘ICBA‐Q5’ showed the greatest improvement in germination percentage, while ‘Titicaca’ and ‘Puno’ demonstrated faster germination. Seed priming thus represents an effective approach to enhance quinoa establishment under high-salinity conditions.