Seed priming with pectic-oligosaccharides improved seed germination and growth of chili

The aim of this study was to assess the impact of pectic-oligosaccharides (POSs) obtained from oxidative degradation of pomelo peel with H2O2 under alkaline conditions on seed germination and growth of chili using the seed priming technique. Two types of POSs (POS-I and POS-II) with different size distributions were prepared. Chili seeds were soaked in 500 ppm of POS solutions for 16 h at two temperatures, 30 and 50 ◦C, with moderate shaking, and then air-dried. The primed seeds were planted on wet filter paper in a Petri dish at 30 ◦C for 9 d and the effects of priming on germination and growth were observed. Priming of seeds with POS at 30 ◦C increased the germination percentage and vigor index at 9 d after sowing by 16.7–20.5% and 16.0–25.5%, respectively, whereas root and shoot length did not differ from the hydropriming. However, there were no significant differences in all growth parameters between POS-I and POS-II treatments. Seedling length and the vigor index of seeds primed with POS at 30 ◦C (29.3–31.0 mm, 2693.9–2914.0) were also significantly higher than those of non-primed seeds (22.9 mm, 2062). Priming the seeds at 50 ◦C had an adverse effect on seed germination, i.e., the germination percentage was reduced by 24.4–31.9% compared to seeds primed at 30 ◦C. It also resulted in a significant reduction in chili seed growth, possibly due to the inactivation of some enzymes in chili seeds