Nutrient analysis of different varieties of meadow fescue ( <scp> <i>Festuca pratensis</i> </scp> Huds.): Calcium contents and molecular mechanisms

Abstract Calcium is an essential element for plants and animals. The quality of forage grasses, particularly their calcium content, is crucial for livestock nutrition. Meadow fescue ( Festuca pratensis Huds.) is a major forage grass, but the nutrient contents of different varieties have not been extensively studied. In this study, we measured the calcium contents in the leaves of 105 varieties of meadow fescues under different conditions and in different stages of leaf development. We also examined water‐soluble calcium, chelated calcium and calcium levels in cell wall components. We determined that No. 102 (from Bulgaria) is a high‐calcium variety and that No. 88 (from the United States) is a low‐calcium variety of meadow fescue. No. 102 had a higher calcium uptake rate than No. 88, but No. 102 also had a notably lower biomass than No. 88. Transcriptomic analysis identified 6288 upregulated genes and 12,249 downregulated genes in No. 102 compared to No. 88, with No. 88 having more upregulated genes related to calcium transport, signaling, aquaporin, β‐galactosidase and β‐glucosidase. These results suggest that a negative feedback mechanism and differences in carbohydrate accumulation contribute to the difference in calcium content between the two varieties. These findings should facilitate the production of superior forage to support the livestock industry.