关键词: 水稻, 高温, 农艺性状, 年际变异, 新品种试验

Abstract:

Rice is one of the most important food crops in the world, and its growth, development, and yield formation are highly sensitive to temperature conditions. This study systematically analyzed the interannual variation characteristics of major agronomic traits and the effects of extreme high temperature based on data from a 2022—2023 centralized demonstration trial of 97 new rice varieties conducted in Shengzhou City, Zhejiang Province. The results showed that, in high-temperature years, the sowing-to-heading period and the heading duration were significantly extended, the seed-setting rate and thousand-grain weight decreased markedly, and the number of effective panicles slightly increased, leading to a significant overall reduction in yield. In contrast, plant height and grains per panicle did not change significantly between years. Correlation analysis revealed that high temperature weakened the synergistic relationships among growth-period traits, strengthened the resource allocation trade-off between panicle number and grains per panicle, and reduced the predictive accuracy of theoretical yield for actual yield. Principal component analysis further demonstrated that high temperature increased the sensitivity of yield component factors to environmental variation, while reducing the coordination among growth-period traits. In summary, extreme high temperature significantly amplifies the interannual fluctuations in major agronomic trait expression of new rice varieties, thereby, affecting the stability and accuracy of variety trial evaluations. Therefore, it is recommended that in the evaluation process of new rice varieties, the impact of key environmental factors such as extreme high temperatures be comprehensively considered, and the variety evaluation system be optimized to enhance the reliability and targeting of new variety breeding and promotion applications.

Key words: rice, high temperature, agronomic traits, interannual variation, new variety trial