How well do you know your growth chambers? Testing for chamber effect using plant traits

Area of Science:

• Plant Science
• Environmental Science
• Experimental Biology

Background:

• Plant growth chambers are crucial for controlled environmental studies.
• A 'chamber effect' can arise from subtle differences between identical chambers, confounding experimental results.
• This study investigated the chamber effect in Vicia faba (broad bean) plants.

Purpose of the Study:

• To determine if a chamber effect exists in walk-in plant growth chambers.
• To identify which plant traits are most effective in detecting chamber effects.
• To differentiate between resolvable and unresolved chamber effects.

Main Methods:

• Broad bean plants were grown in eight walk-in chambers.
• Measurements included chlorophyll fluorescence, gas exchange, biomass, reproductive yield, anatomy, and leaf stable carbon isotopes.
• Analysis focused on identifying variations attributable to chamber differences rather than experimental treatments.

Main Results:

• Four out of eight chambers exhibited a significant chamber effect.
• Fresh weight and flower count were the most effective traits for detecting chamber effects, detecting them in three chambers.
• Stable carbon isotopes (δ(13)C), net CO2 assimilation (An), stomatal conductance (gs), and performance index varied in their ability to detect chamber effects.

Conclusions:

• Fresh weight and flower count provide efficient detection of chamber effects in broad bean studies.
• δ(13)C, gs, and An measurements aid in distinguishing between resolvable (malfunctioning components) and unresolved (unknown factors) chamber effects.
• Resolvable effects require chamber repair, while unresolved effects necessitate robust experimental design and replication.