S08 - Session O2 - Plant phenotyping for the growth analysis of individual plants based on cohort research in PFALs

Authors: Eri Hayashi *, Toyoki Kozai

Plant factories with artificial lighting (PFALs), with well-insulated and almost airtight structures, have the potential of enabling the production of high quantities of high-quality plants year-round in conjunction with achieving highly efficient resource utilization. However, despite the precisely controlled environment in PFAL, variations in the growth of plant individuals have been found, which exerts adverse effects on the plant productivity of PFAL. Plant phenotyping serves an essential role in understanding how the surrounding microenvironment of individual plants, management factors, and genotype affect variations in the phenotype of individual plants. The modular plant phenotype measurement system was developed, with small cameras and sensors achieving low cost, focusing on practicality and scalability in commercial PFALs, along with a cultivation method similar to the one in commercial PFALs. Experiments were conducted on seed germination, the initial stage of seedling, and subsequent growth of individual plants of romaine lettuce ( Lactuca sativa L. var. longifolia), using two-dimensional camera images, and to analyze how microenvironment and management factors affect the phenotype (e.g., growth) variations of individual plants as a serial study for plant cohort research. In the plant cohort research, the life cycle phenome history of individual plants can be obtained noninvasively and continuously and analyzed from seed sowing to harvesting with phenotyping units, together with the time series data on environment, management, and resource inputs/outputs in PFAL (Kozai et al., 2018). Using the time series data sets in the data warehouse, plant cohort research makes it possible to identify optimal set points of environmental factors for maximizing multi-objective function, in parallel with improving plant productivity, selection of seedling for grading and breeding new cultivars in PFAL (Kozai et al., 2018). Kozai, T., et al. (2018). "Plant Cohort Research and Its Application," in Smart Plant Factory , ed. T. Kozai (Berlin: Springer), 413-432.