Abstract: | - Welsh onions (Allium fistulosum L.) are often affected by stressful environments, such as high light and drought, during summer cultivation, which hinders their growth.
- We used CO2 assimilation, OJIP transient and MR curves to analyse the photosynthetic characteristics of Welsh onion.
- The results showed that single high light stress caused a decrease in the net photosynthesis rate through stomatal limitation, while the single drought treatment and the combined stress induced nonstomatal limitation. FO and FJ increased, Fm decreased, and a distinct K‐phase was induced. High light and drought stress blocked MR transients, leading to a gradual decrease in VPSI and VPSII‐PSI.
- In general, photosynthesis of Welsh onion was inhibited by high light and drought, which destroyed the receptor and donor side of PSII and reduced electron transport capacity of PSII and PSI.
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