Seed Priming With Colchicine Improves Morpho-Anatomical, Fluorescent, and Biochemical Attributes in the Field-Grown Spinach (Spinacia oleracea L.)

A two-year field trial was carried out to identify the most effective concentration of colchicine (Colch) for seed priming in spinach (Spinacia oleracea L., cv. Desi Palak) with the aim of improving crop performance and resilience under changing environmental conditions. The study revealed that seed treatment with 0.07% Colch significantly enhanced morphological, anatomical, fluorescence, and biochemical characteristics of spinach, whereas higher concentrations negatively affected growth. In comparison to the untreated control, the 0.07% Colch treatment resulted in notable increases in germination rate (20.3%), plant height (62.2%), number of leaves plant⁻¹ (51.4%), leaf area (63.6%), crop growth rate (54.3%), and leaf yield (25.9%). Positive effects were also observed on stomatal size (44.4%), stomatal index (23.1%), leaf thickness (81.5%), quantum yield of photosystem II (46.4%), chlorophyll content (49.7%), linear electron flow (74.4%), and the enzymatic activities of catalase (23.4%), superoxide dismutase (33%), and peroxidase (14.3%), along with antioxidant capacity measured in terms of 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activity (28.3%). Moreover, the chromosomal count was doubled in plants treated with 0.07% Colch compared to the control, and polyploidy was cytogenetically verified, confirming its effectiveness in inducing genome duplication. Conversely, reductions were recorded in stomatal density (42.8%), nonphotochemical quenching (threefold), nonregulatory energy dissipation (twofold), hydrogen peroxide (31.5%), and superoxide anion levels (25.5%). Thus, the above findings demonstrate that 0.07% Colch seed priming can induce beneficial changes in the morphology, anatomy, physiology, and biochemical profile of spinach, providing practical implications for breeding strategies and sustainable crop development.