Device for diagnosing environmental stress in plants and method for diagnosing environmental stress

An environmental stress diagnosis device that diagnoses an environmental stress state of a plant sample, comprising:

• a measurement light source that radiates a measurement light to the plant sample;
• an induction light source that radiates a photosynthesis inducing light to the plant sample;
• a sealed chamber that stores the plant sample and allows entry of the measurement light and the photosynthesis inducing light;
• a transmitted light detector that detects the measurement light transmitted through the plant sample as a transmitted light;
• and a control unit that receives the transmitted light detected by the transmitted light detector as a measurement signal, wherein
• the measurement light source radiates two types of a first measurement light and a second measurement light having different wavelengths to the plant sample,
• the induction light source radiates two types of a first photosynthesis inducing light and a second photosynthesis inducing light having different wavelengths to the plant sample,
• the transmitted light detector detects a transmitted light of the first measurement light as a first transmitted light and detects a transmitted light of the second measurement light as a second transmitted light,
• the control unit has a control circuit that controls the measurement light source and the induction light source in correspondence to the plant sample, and an analysis circuit that analyzes a detection result acquired by the transmitted light detector,
• the analysis circuit calculates a light absorption difference between the first transmitted light and the second transmitted light, and calculates Y(ND) which is a state in which P700 in photosystem I has been oxidized in photosynthesis as a ROS marker which is a reactive oxygen species suppression index for a plant by utilizing the light absorption difference, and
• the analysis circuit further diagnoses the environmental stress state of the plant sample by utilizing the ROS marker.