Principal component analysis for yield and quality traits of sugar beet varieties treated by proline under saline stress

Background In our study, saline soil stress negatively affects root and sugar yields. Therefore, six sugar beet varieties were evaluated using different levels of proline to decrease the harmful effect of salinity in 2022/2023 and 2023/2024. Methods Proline treatments (control, 50, 100, and 200 ppm) were sprayed in the main plots, and six sugar beet varieties were arranged within subplots, such as Smart Seza, Smart Meyra, BTS 3880, BTS 3740, SV 2003, and Wombat Smart during the two seasons. Results The elite varieties recording high mean values for growth and yield traits were Smart Seza and Smart Mayra, whereas the best varieties reflecting high mean values for quality traits were SV2003 and Smart Seza. The root diameter (RD), root length (RL), top fresh weight (TW), root fresh weight / plant (RW), extractable sugar (EXT), sucrose (SU), and sugar yield (SY) showed a positive relationship with the root yield of sugar beets, whereas potassium (K), α-amino (N), sodium (Na), and sucrose loss to molasses (SLM) showed a negative relationship with sugar yield. Results revealed that out of 12, only three principal components (PCs) showed 95.6% variability among the studied traits. Maximum variation was found for PC1; therefore, the selection of important characteristics that increase sugar yield under PC1 may be desirable. Conclusions A 200 ppm proline concentration sprayed on sugar beet varieties can be recommended to achieve high yield and quality sugar traits. In general, Smart Seza and Smart Mayra were the best varieties with high mean values for growth, yield, and quality attributes.