Cucumber (Cucumis sativus L.) is a high-value Asiatic vegetable crop where seed quality directly governs crop establishment and yield. While freshly harvested seeds typically exhibit good germination, their storability is poor. Ageing manifests not as an immediate decline in germination but as reductions in seedling vigour, emergence speed and membrane stability, traits that ultimately determine stand establishment. This disconnect between laboratory germination and actual field performance makes conventional seed testing insufficient for reliable crop stand establishment predictions. Seed priming is widely used to improve germination and uniformity, yet it accelerates ageing and compromises storage life, creating a practical bottleneck for seed systems. The present study evaluated physiological responses of cucumber cv. Punjab Naveen seeds stored at 4°C for 12 months following halo-priming—KNO3, K2HPO4, KH2PO4 and priming with cell cycle inhibitors—mimosine and hydroxyurea. Bimonthly testing revealed that 200 µM mimosine priming consistently maintained higher germination; improved emergence speed and vigour indices; reduced mean germination time and enhanced membrane stability by 15% compared with untreated seeds. KH2PO4 priming at 1/103 and 1/105 M also enhanced seedling growth and vigour indices initially but declined sharply with prolonged storage. Storage stress significantly influenced seed physiological quality with improved vigour-related characteristics up to 10 months before declining at 12 months. Overall, 200 µM mimosine priming was most effective in extending seed longevity with improved vigour than untreated seeds. Enhanced membrane stability achieved at seed level could be expected to translate into stronger seedling establishment and ultimately higher yield in the fields. This study provides preliminary physiological evidence that can guide crop- and genotype-specific priming strategies that balance immediate germination benefits with long-term storage potential in cucumber.
Varinda et al. (Tue,) studied this question.