Seed priming with pectic-oligosaccharides improved seed ger-2 mination and growth of chili

The aim of this study was to assess the impact of pectic-oligosaccharides (POS) obtained from oxidative degradation of pomelo peel with H₂O₂ under alkaline condition on seed germination and growth of chili using the seed priming technique. Two types of POSs, (POS-I and POS-II), having 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 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-priming seeds (22.9 mm, 2062). Priming the seeds at 50 °C had an adverse effect on seed germination, i.e., germination percentage was reduced by 24.4-31.9% compared to seeds primed at 30 °C. It also resulted in a significant reduction of chili seed growth, possibly due to inactivation of some enzymes in chili seeds.