The effect of watering regime on the disease severity of Fusarium pseudograminearum wheat seedlings

Fusarium pseudograminearum inoculated and noninoculated genotypes with different susceptibility to crown rot were watered to either field capacity or a reduced watering (67% of field capacity) regime in three controlled environment experiments. Six bread wheat genotypes were included in each trial conducted in 2016 and 2017. The growth room was set to 25°C/21°C in a 12 h day/night schedule and a light energy of 600 μmol m⁻² s⁻¹. One file "Abdulsada et al 2024a (published).xlsx" contains all data and trait descriptions. Data collected included the % of leaf sheath 1, leaf sheath 2, leaf sheath 3 and leaf sheath 4 covered in crown rot lesions, average and total disease ratings across leaf sheaths, shoot weight, shoot length. Gas exchange parameters were measured using a portable photosynthesis system (LI-6400; LICOR). The measurements were taken from the first expanded leaf on two plants per pot. The temperature in the 6 cm2 chamber was set at 25°C and the leaf level temperature was maintained at 1700 μmol m⁻² s⁻¹ using an in-built LED lamp (red/blue). Vapour pressure deficit was maintained between 1.9 and 2.1 kPa within this chamber during measurements. Each leaf was allowed 10–15 min to reach a steady state before measurements were taken. Rate of photosynthesis (A), stomatal conductance (gs), internal CO2 concentration (Ci) and transpiration rate (E) were recorded between 10:00 and 12:00 hours. An across experiment analysis of data from the gas exchange parameters (photosynthesis, stomatal conductance, internal CO2 concentration and transpiration rate) and disease severity assessments was conducted using a linear mixed model.