High-throughput phenotyping to dissect genotypic differences in safflower for drought tolerance

PLoS One. 2021 Jul 23;16(7):e0254908. doi: 10.1371/journal.pone.0254908. eCollection 2021.

Abstract

Drought is one of the most severe and unpredictable abiotic stresses, occurring at any growth stage and affecting crop yields worldwide. Therefore, it is essential to develop drought tolerant varieties to ensure sustainable crop production in an ever-changing climate. High-throughput digital phenotyping technologies in tandem with robust screening methods enable precise and faster selection of genotypes for breeding. To investigate the use of digital imaging to reliably phenotype for drought tolerance, a genetically diverse safflower population was screened under different drought stresses at Agriculture Victoria's high-throughput, automated phenotyping platform, Plant Phenomics Victoria, Horsham. In the first experiment, four treatments, control (90% field capacity; FC), 40% FC at initial branching, 40% FC at flowering and 50% FC at initial branching and flowering, were applied to assess the performance of four safflower genotypes. Based on these results, drought stress using 50% FC at initial branching and flowering stages was chosen to further screen 200 diverse safflower genotypes. Measured plant traits and dry biomass showed high correlations with derived digital traits including estimated shoot biomass, convex hull area, caliper length and minimum area rectangle, indicating the viability of using digital traits as proxy measures for plant growth. Estimated shoot biomass showed close association having moderately high correlation with drought indices yield index, stress tolerance index, geometric mean productivity, and mean productivity. Diverse genotypes were classified into four clusters of drought tolerance based on their performance (seed yield and digitally estimated shoot biomass) under stress. Overall, results show that rapid and precise image-based, high-throughput phenotyping in controlled environments can be used to effectively differentiate response to drought stress in a large numbers of safflower genotypes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Automation, Laboratory / methods
  • Biomass
  • Carthamus tinctorius / genetics*
  • Carthamus tinctorius / physiology
  • Droughts*
  • Genotype*
  • Phenomics / methods*
  • Phenotype
  • Plant Breeding / methods*
  • Stress, Physiological*

Grants and funding

All authors were awarded funding from the Australian Government Cooperative Research Centre Project (CRC-P54024). Agriculture Victoria and the Grains Research & Development Corporation provided infrastructure funding for the establishment of the Plant Phenomics Victoria, Horsham facility. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.