Comparison of photosynthetic capacity between two strawberry genotypes

Abstract

Amount and activity of the primary carboxylating enzyme of photosynthesis, photosynthetic gas exchange, and leaf anatomical parameters were measured in two strawberry species, RCP37 (Fragaria chiloensis) and 'Midway' (Fragaria x ananassa). Photosynthetic capacity was greater in RCP37, as indicated by a greater CO₂ assimilation rate at ambient CO₂ concentration (350 μmol mol⁻¹), Rubisco amount, carboxylation efficiency, residual conductance, ratio of mesophyll surface area to leaf area, and leaf N content, compared to 'Midway'. The ratio of mesophyll surface area to leaf area, mesophyll layer thickness and palisade layer thickness were significantly different between RCP37 and 'Midway'. The large surface area of palisade cells in RCP37 accounted for the difference in the ratio of mesophyll surface area to leaf area. Results show that RCP37 has higher photosynthetic capacity than 'Midway'. RCP37 might provide promising resources of germplasm for improving photosynthetic rate or yields of cultivated strawberry varieties.