Germination and Seedling Development Responses of Sunflower (<i>Helianthus annuus</i> L.) Seeds to Temperature and Different Levels of Water Availability

Abstract

Abiotic variables are crucial for seed germination and seedling development. In the present work, we attempted to determine the optimal conditions (temperature, water, seed density, and fungal growth) for sunflower seed development (Helianthus annus L. Larissza). The germination of sunflower seeds was investigated under controlled conditions at eight consistent temperatures: 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C, and 40 °C. For the water test, there were 12 water levels based on one-milliliter intervals and 18 water levels based on thousand kernel weight (TKW). In addition, four seed densities (6, 8, 10, and 12) and two antifungal application techniques (sterilization and growing medium) were examined. The results showed that temperature has a significant effect on seed germination, germination timing, and seedling development. Temperatures between 15 and 35 degrees Celsius were optimal for germination, with 25 degrees Celsius being the optimal temperature for significant germination and seedling development. Beginning at 0.6 mL, or 125% of the TKW, sunflower seeds can germinate under a wide range of water availability. The optimal range for seedling development (8.2–11.4) is wider than the optimal range for dry matter accumulation, which is 5.8–8.2 mL or 1000–1625% of the TKW. The finding that a density of 10 to 12 seeds per 9 cm Petri dish demonstrates the most exceptional values is advantageous for future research and breeding projects, particularly when seeds are scarce. Seed priming is a more effective antifungal application technique than other techniques.

Keywords

• sunflower
• seed germination
• seedling development
• seed density
• temperature
• water stress