Spectral Images Analyses to Assay Soybean Response to Abiotic Stress

Recent gene-transformation technology and increasing genomic understanding have accelerated crop breeding, particularly creating new lines. However, technologies for phenotyping and field screening still do not meet the needs of modern breeding due to lack of experienced field breeders and high costs of field screening, and a new high throughput screening (HTS) method based on phenomics is urgently required. Plant spectral images reflected under a certain environment contain biological information. Therefore, this study was conducted to test if spectral image analyses of soybean grown under abiotic stress conditions can be used for early diagnosis of soybean response to abiotic stress and screening stress tolerant soybean. Thermal image and fluorescence image data were then correlated with crop physiologic parameters to test them as non-destructive indicators of soybean responding to salt and drought stresses. Our results showed that both thermal and fluorescence image data are closely associated with the strengths of salt (NaCl) and osmotic (PEG) stresses and physiologic responses at early stage after stress treatments. Plant body temperature increased with abiotic stress, giving negative correlations with physiologic parameters, while plant fluorescence decreased with abiotic stress, giving positive correlations with physiologic parameters. Therefore, both thermal  and fluorescence images of soybean can be used for screening salt and drought stress tolerant soybean and be a part of HTS tool for future soybean breeding.