การประเมินลักษณะทนน้ำท่วมฉับพลันของข้าวสายพันธุ์ปรับปรุงใหม่ ในสภาพบ่อทดลอง

The Central Region of Thailand has been affected by natural disasters such as heavy rainfall and flash floods, resulting in slow drainage from flooded areas and causing significant impacts on rice cultivation. This study aimed to evaluate the flash flood tolerance of newly improved rice lines incorporating the Sub1 gene, which confers submergence tolerance. Eight improved rice lines and two standard check varieties were tested at Ruamjai Pattana Kwamroo Company Limited from June to October 2025. The experiment was arranged in a Randomized Completely Block Design (RCBD). Data were recorded for plant elongation percentage (PPE), plant survival percentage (PPS), and post-submergence recovery score (PR) as evaluation criteria. The results showed that the elongation percentage of the improved rice lines ranged from 7.96–26.13%, with an average survival rate of 90.55%. The recovery score after water recession ranged from 1 to 5. Five improved rice lines DS19-MP-3, DS19-MP-4, DS19-MP-5, DS19-MP-6, and DS19-MP-9 exhibited flood tolerance and recovery performance comparable to the standard check varieties, with no statistically significant difference in survival percentage. Among them, DS19-MP-3 showed outstanding tolerance to flash flooding, with a plant elongation percentage of 22.46%, indicating strong submergence tolerance, a 100% survival rate, and an excellent recovery score (score 1), characterized by only slight leaf tip drying. These results suggest that DS19-MP-3 possesses high adaptability to fluctuating environmental conditions and is suitable for further improvement, development, or yield testing to benefit farmers affected by flash flooding.