Tropentag, October 7 - 9, 2008 in Hohenheim "Competition for Resources in a Changing World: New Drive for Rural Development"

Nutrient Seed Priming Improves Germination Rate and Seedling growth under Submergence Stress at Low Temperature

University of Hohenheim, Institute of Plant Nutrition, Germany

Abstract

Seed quality plays an important role in crop production. Seed mineral nutrients are one of the key factors determining seed quality. Micronutrients take part in a number of biochemical and physiological processes during germination and early seedling establishment. Due to important functions in membrane stabilisation, free radical detoxification and secondary plant metabolism sufficient availability of micro-nutrients such as Zn, Mn or B in the seed is essential for seed germination and seedling growth, particularly when germinating seeds or seedlings are facing abiotic and biotic stress.
‘Nutrient seed priming' is a technique in which seeds are soaked in a mineral nutrient solution with subsequent re-drying to the initial moisture content. The final goal is an improvement of germination rate, early seedling growth and stress resistance, acting via an improved micronutrient status and a pre-activation of metabolic pathways important for germination during the pre-imbibition treatment (priming effect).
In the present study, soybean (Glycine max L.) cv. ‘Conquista' seeds were primed with nutrient solution of Mn, Zn and B (Mn and Zn at the rate 5 and 15 mM using MnSO₄ and ZnSO₄ solutions respectively, and B at 0.5 and 10 mM as Boric acid solution) for 12 hours at 20ºC between 5 layers of moist filter paper. After seed nutrient priming seeds were dried to initial seed moisture content and stored at 4°C. After one week of storage, seeds were submerged into chilled water at 4°C for 24 hours as a stress treatment and subsequently tested for germination and early seedling development. Nutrient seed priming significantly increased content of micro-nutrients in the seeds up to 20 times for Mn, 5 times for Zn and 2 times for B. Boron seed priming increased germination rate significantly by 80% compared to unprimed control, which was not able to produce any seedling under these stress conditions.

Keywords: Micronutrients, nutrient seed priming, seed germination, soybean, submergence stress

Contact Address: Volker Römheld, University of Hohenheim, Institute of Plant Nutrition, 70593 Stuttgart, Germany, e-mail: roemhelduni-hohenheim.de