Effects of Seed Priming with Proline and Glycine Betaine on Germination, Seedling Growth, and Photosynthetic Pigments of Rice (Oryza sativa) under Chilling Stress

Abstract

Aims: Rice grown in late Rabi season frequently results poor germination and establishment because of exposure to extreme low temperature or chilling stress. Seed priming is an effective seed treating technique for uniform and good germination in various crops under different abiotic stresses. The present study was undertaken to assess the role of different seed priming agents in seed germination and seedling growth of rice (BRRI Dhan 29) under chilling stress (CS). Place and Duration of Study: a pot experiment was carried out at the Department of Seed Science and Technology, Bangladesh Agricultural University during Late November – Mid December 2021. Methodology: The rice seeds (BRRI Dhan 29) were soaked in different priming agents (hydro-priming, 20 mM proline and glycine betaine) for 30 min. The primed seeds were exposed to cold stress (under 5°C) in the refrigerator. The untreated seeds were used as control. Results: The outcomes shown that proline (Pro) and glycine betaine (GB) priming had a favorable effect on germination and survival rate, shoot and root length, shoot and root weight, and photosynthetic pigments of leaves under CS. Among the treatments, Pro and GB at 20 mM and warm water performed better; while priming with tap water and Pro and GB at a concentration of demonstrated insignificant performance over control but considerable over stress in the majority of the parameters. The findings showed that seed priming generally has a favorable effect on germination and survival, shoot and root length and weight, and leaf chlorophyll content. Conclusion: Proline, betaine, or warm water priming (at 45°C for 5 min.) can be thought of as a lasting priming agent. This means that priming may be an efficient strategy to boost seed germination and better seedling growth of rice under chilling stress.