Description
The Phenovator is a high-throughput phenotyping system in which 1440 plants with a maximum diameter of 6 cm can be grown and imaged. The system is designed to be used with Arabidopsis, but can also be used for other small plants and seedlings of larger species. The system is built into a 15-m2 climate controlled plant growth room, which can provide a maximum irradiance of 600 µmol m-2 s-1 and a minimum day-time temperature of 10 ⁰C. The plants are grown hydroponically in individual rock-wool blocks. The plants and their rock-wool blocks are fixed into custom-built portable palettes. This palette system allows plants to be grown in a way optimal for phenotyping, and the portability creates flexibility in terms of where plants can be grown and the treatments they can be subjected to before phenotyping, and their handling afterwards. The hydroponic fertigation system used in the Phenovator allows two separate nutrient and watering regimes to be concurrently applied. A typical plant growth and phenotyping run in the Phenovator will last up to 4 weeks. Phenotyping is primarily imaging based, though plant material can be harvested from the growth system for (bio)chemical analysis etc. The imaging system is based around a moving camera system which can image all plants multiple times per day and night. Images are made using either reflected light in the spectral range of 400-850 nm, or chlorophyll fluorescence. The reflected light imaging allows conventional RGB, near-infrared light (for night-time imaging), and chlorophyll and anthocyanin content images to be made. The fluorescence images can be used to calculate images of photosynthetic parameters, such as the light-use efficiency for PSII electron transport (ΦPSII) and non-photochemical quenching (NPQ). The time required to image all plants depends on the imaging protocol but is typically one hour or less. This plant growth and phenotyping system is flexible and reproducible. Images from the Phenovator are analysed using custom written software that substantially automates the image-analysis process.
Technical Details
The modulated chlorophyll fluorescence measuring protocol will allow the measurement of the basic chlorophyll fluorescence yield parameters Fo, Fm, F’, Fm’ and Fo’. From these basic measurements, other more physiologically useful fluorescence-derived parameters will be immediately available as images (ie the data is in a spatially resolved array) from within the protocol, eg dark-adapted Fv/Fm, ΔF/Fm’, qE, Fv’/Fm’, qP, Φf,D and ΦNPQ.
Applications
This is a state-of-the-art infrastructure to determine ΦPSII as a proxy for photosynthesis efficiency, NPQ, plant pigmentation and plant growth at high throughput for a large number of plants, which is an excellent opportunity to collect time-course data for genetic and physiological analyses.