## 3 Results
### Genotype Variations for Biomass and Biological Yield
At the BT stage, the red-edge region (700-750 nm) and wavelengths between 1150-1300 nm in the NIR region exhibited a negative correlation with the three traits, and a positive correlation was expressed in the wavelength region between 750-1150 nm (Figure 4). The signs of r between the SWIR wavelengths and three traits depended on the growth stage: r was negative at the BT and AN stages, whereas it was positive at the EMG stage (Figure 4). Additionally, the wavelengths in the three regions of the spectrum showed a higher correlation with the BDW-AN trait than those of the BDW-BT and BY traits at the BT and AN stages, and they were best correlated with the BY trait, followed by the BDW-AN trait, at the EMG stage (Figure 4). The wavelengths in the VIS region showed no significant correlation with any trait at the BT stage, and they showed weak to strongly significant correlations (r ranged from \(-0.25\) to \(-0.80\)) with all traits at the AN and EMG stages. The wavelengths in the NIR region had a weak to strong positive correlation (r ranged from 0.25 to 0.82) with the three traits at the AN and EMG stages, and the red-edge band was the only wavelength range in the NIR region that exhibited a weak to strong negative correlations (r ranged from \(-0.30\) to \(-0.75\)) with the three traits at the BT stage (Figure 4). At the BT stage, the wavelengths in the SWIR region exhibit a weak to strong correlation (r ranged from \(-0.30\) to \(-0.75\)) with the three traits in both years, and the correlation depended on the traits and year in the AN and EMG stages. In the first year, most wavelengths in the SWIR region were only moderately correlated with the BDW-AN trait at the AN stage and the BY trait at the EMG stage. In the second year, these wavelengths exhibited a moderate correlation with only the BDW-AN trait at the AN stage and three traits at the EMG stage (Figure 4). Figure 3: Summary statistical information (minimum, maximum, and standard deviations) of canopy spectral reflectance in the full range of the spectrum (350–2500 nm) across 64 wheat genotypes grown in 150 mM NaCl at three different growth stages. Genotypic Variations for Spectral Reflectance Indices and Their Relationship with Biomass and Biological Yield  
Tables 2 and 3 display summary statistical information (ANOVA analysis, minimum, maximum, mean, LSD, and significant level of F-test) for different vegetation- and water-related SRIs calculated at different growth stages. Mean squares from the ANOVA analysis combined over years and growth stages revealed that year, growth stage, and genotype main effects were highly significant (\(p\) < 0.001 and 0.0001) for all SRIs, except the published green normalized difference vegetation index (GNDVI-P), for which the year effect was not significant. The two-way (growth stage \(\times\) year, genotype \(\times\) year, and genotype \(\times\) growth stage) and three-way (genotype \(\times\) growth stage \(\times\) year) interactions were highly significant for all SRIs (Table 2). Figure 4: Correlation coefficients of spectral reflectance at single wavelength in the full range of the spectrum (350–2500 nm) and measured at the booting, antibes, and the early milk-grain stages with plant dry weight measured at booting (BDW-BT) and antibes (BDW-AN) growth stages and biological yield (BY) across 64 wheat genotypes grown in 150 mM NaCl for two years. The results in Table 3 also revealed a wide range between the minimum and maximum values among genotypes for all SRIs at the three stages. For nearly all SRIs, the maximum values were two to four times higher than the minimum values. Additionally, the values of all vegetation-related SRIs and two indices from water-related SRIs (the modified water index (WI-M) and published normalized difference water index (NDWI-P) showed a continuous decrease from the BT to the EMG stage. By contrast, the values of other water-related SRIs increased from the BT to the EMG stage (Table 3).