1. Dr. Ferenc Horváth Dr. Barnabás Wodala
Preliminary photosynthesis measurements of selected wheat cultivars prior to inoculation
Dr. Ferenc Horváth Dr. Barnabás Wodala

2. The LI-6400 Portable Photosynthesis System

3. The LI-6400 Portable Photosynthesis System

4. The LI-6400 Portable Photosynthesis System

5. An open system
In an open system, photosynthesis and transpiration are computed
from the differences in CO2 and H2O between in-chamber conditions and pre-chamber conditions.

6. Schematic without a CO2 mixer

7. Schematic with a CO2 mixer

8. IRGA (InfraRed Gas Analizator)
CO2 measurement: 4,26 μm
H2O measurement: 2,59 μm
Infrared light source (wide spectrum)
Gas inlet
Gas outlet
Filter
Measuring box
Detector
Signal processing
Indicator

10. Matching

11. Incoming concentrations must be stable
breath, for example, is typically μmol CO2 (mol air)-1
Ambient air contains 360 μmol CO2 (mol air)-1

12. Chlorophyll a fluorescence
Light
Reflected light
Mehler reaction
ETR
PSII
PSI
ΦPSII
Photosynthesis
Transmitted light
Photorespiration
Chlorophyll a fluorescence
Heat dissipation

13. preliminary measurements
Setting up the instrument (Licor 6400, an open path gas exchange system)
4 selected wheat genotypes (1 week before the infection)
PARout: sunny, depends on angle, 600 – 1800 µmol photon m-2 s-1
PARin: fixed, 1000 µmol photon m-2 s-1 (10% blue, 90% red)
Tair: °C
Tleaf: °C

14. Calculated parameters

15. Thank you for your attention!