Affordable Phenotyping of Winter Wheat under Field and Controlled Conditions for Drought Tolerance

Abstract

Drought stress is one of the key plant stresses reducing grain yield in cereal crops worldwide. Although it is not a breeding target in Northern Europe, the changing climate and the drought of 2018 have increased its significance in the region. A key challenge, therefore, is to identify novel germplasm with higher drought tolerance, a task that will require continuous characterization of a large number of genotypes. The aim of this work was to assess if phenotyping systems with low-cost consumer-grade digital cameras can be used to characterize germplasm for drought tolerance. To achieve this goal, we built a proximal phenotyping cart mounted with digital cameras and evaluated it by characterizing 142 winter wheat genotypes for drought tolerance under field conditions. The same genotypes were additionally characterized for seedling stage traits by imaging under controlled growth conditions. The analysis revealed that under field conditions, plant biomass, relative growth rates, and Normalized Difference Vegetation Index (NDVI) from different growth stages estimated by imaging were significantly correlated to drought tolerance. Under controlled growth conditions, root count at the seedling stage evaluated by imaging was significantly correlated to adult plant drought tolerance observed in the field. Random forest models were trained by integrating measurements from field and controlled conditions and revealed that plant biomass and relative growth rates at key plant growth stages are important predictors of drought tolerance. Thus, based on the results, it can be concluded that the consumer-grade cameras can be key components of affordable automated phenotyping systems to accelerate pre-breeding for drought tolerance.

Climate Change Impact on Wheat Performance—Effects on Vigour, Plant Traits and Yield from Early and Late Drought Stress in Diverse Lines

“…Water deficit inhibits the growth of plants by inducing changes of different types, i.e., to the physiological, biochemical, morphological, and molecular characteristics [ 10 ]. Many traits besides yield are significantly influenced by drought stress, i.e., flag-leaf area [ 11 ], root and plant biomass [ 12 , 13 ], days to anthesis and tillers per plant [ 14 ]. To screen for genotypes with high yield potential under stress conditions, a stress-tolerance index (STI) was developed and is used as an effective selection criterion [ 15 ].…”

Genome-Wide Association Analysis and Genomic Prediction for Adult-Plant Resistance to Septoria Tritici Blotch and Powdery Mildew in Winter Wheat

“…The Nordic Genetic Resource Centre (NordGen, Alnarp, Sweden) preserved winter wheat accessions comprising landraces and historical cultivars collected from the Scandinavian countries 1 . This preserved germplasm has encompassed a rich genetic variation for various traits of agronomic importance ( Chawade et al, 2018 ), including resistance to STB at the seedling stage ( Odilbekov et al, 2019a ), adult-plant resistance (APR) to rust and PM ( Hysing et al, 2006 , 2007 ), and drought tolerance ( Kumar et al, 2020 ). The current study used 175 genotypes comprising both landraces and historical cultivars of the Nordic origin with the following objectives: (I) to evaluate the genetic variation in response to STB and PM resistance; (II) to estimate the genotype-by-environment (G × E) interaction for STB and PM resistance across years and locations; (III) to detect valuable QTLs for STB and PM resistance via GWAS analysis; and (IV) to estimate the GEBVs of individual genotypes for STB and PM APR using different GP models.…”

Phenocave: An Automated, Standalone, and Affordable Phenotyping System for Controlled Growth Conditions

“…Plant phenotyping systems designed to analyze projected leaf area or canopy biomass over plant development time using a single camera in the visible light range (RGB) have proven to be helpful for the estimation of growth rate, health status, drought or salinity stress, and early vigor [ 17 , 18 , 19 , 20 , 21 ]. Other systems use more sophisticated commercial optical sensors like hyperspectral or multispectral imaging [ 22 ].…”