ผลกระทบของอุณหภูมิสูงในระยะเจริญพันธุ์ต่อการติดเมล็ด ผลผลิต และคุณภาพเมล็ดของข้าวสายพันธุ์ปรับปรุง

    Rice is vital for global food security. However, climate change and increasing temperatures adversely affect rice growth and development, particularly during the reproductive stage. Therefore, this study aimed to investigate the effects of high temperature during the reproductive stage on seed set, yield, and grain quality of improved rice lines. Five improved rice lines (RJP-HT-01 to RJP-HT-05) and one standard check variety (Kimhan) were grown under high temperature condition (40–45°C) during the reproductive stage and compared with those cultivated under field condition. The results showed that high temperature condition significantly reduced seed setting (%) and the number of filled grains per panicle. However, these traits did not differ significantly among the rice lines/varieties. In terms of grain quality, RJP-HT-01, RJP-HT-02, and RJP-HT-04 grown under high temperature showed no difference in chalkiness compared with those grown under field condition. In contrast, RJP-HT-03, RJP-HT-05, and the Kimhan variety exhibited increased chalkiness under high temperature condition. Nevertheless, RJP-HT-05 showed the lowest chalkiness, the highest yield, as well as the earliest flowering and harvesting under both high-temperature and field conditions. Therefore, RJP-HT-05 has potential for further development and promotion as a heat-tolerant rice variety for future rice production.