Phenotypic Diversity of Photosynthetic Characteristics in 16 Cucumber Accessions Selected from the Core Collection

Abstract

To investigate the phenotypic variation of cucumber photosynthesis, net photosynthetic efficiency of cucumbers were measured by LI-6400XT Portable Photosynthesis System. Non-rectangular hyperbolic model was adopted to fit the light response curve. We used 16 cucumber accessions selected from the core collection that consists of over 400 accessions. As a result, cucumbers show a moderate variance in the phenotype of light compensation point (LCP), light saturation point (LSP) and apparent quantum efficiency (AQY), dark respiration rate (Rd), and maximum net photosynthetic rate (Amax). In a detail, the coefficient of variation (CV) of LCP and Rd is 48.97% and 48.09%, respectively, which is relatively high. In contrast, the CV values of Amax, LSP and AQY are all smaller than 25%. These results help us get better understanding about the phenotypic variation of photosynthesis in cucumber germplasm.