不同晚籼稻品种冠层温度的差异及其与产量的关系

Genetic Difference in the Canopy Temperature of Different Late-season Indica Varieties and its Relationship with Grain Yield

明确不同水稻品种冠层温度的差异及其与产量的关系对耐热基因型的选育以及制定合理的避热栽培措施均具有重要意义。试验结果表明,不同晚籼稻品种白天平均冠层温度的差异均未达到显著水平。以14：00的冠层温度进行的聚类分析表明,品种间冠层温度的差异在不同生育期表现较为一致。其中,五优308在孕穗期、抽穗期和灌浆期的冠层温度均最低,而M112和金优998在3个时期的冠层温度均最高,分别属于低温型和高温型品种。孕穗期、抽穗期和灌浆期的气冠温差（气温与冠层温度的差值）与水稻产量和结实率均呈显著的正相关关系。气冠温差与有效穗数和千粒质量无显著的相关关系,而与每穗粒数呈正相关关系,但仅在抽穗期达到显著水平。气冠温差与水稻的株高、剑叶的长度、顶3叶的叶角以及倒1节的长度均无显著的相关关系。气冠温差与群体的透光率呈显著的负相关关系,而与根系伤流量呈显著的正相关关系。

Clarifying the genetic difference in the canopy temperature of different late-season indica rice varieties and its relationship with yield is critical to screen heat-tolerant genotypes and to make appropriate management practices to avoid heat stress.The present study indicated that there were no significant differences in the mean daytime canopy temperature among different late-season indica varieties.Cluster analysis using the canopy temperature determined at 14：00 showed that the genetic difference in canopy temperature was consist-ent across different growth stages.Wuyou 308 showed the lowest canopy temperature at the booting,heading,and grain filling stages,with M112 and Jinyou 998 the highest,and thus could be classified as the low-and high-temperature types, respectively.Canopy temperature depression （ the difference between air temperature and canopy temperature,CTD） was significantly and positively correlated with grain yield and the percentage of filled grains,regardless of growth stages.There were no significant correlations between CTD and the number of panicles and 1000-grain weights.The number of grains per panicle was positively correlated with CTD,but only significantly at the heading stage.No significant correlations were found between CTD and plant height, the length of the flag leaf,the angle of the top three leaves,and the length of the first internode.CTD was signifi-cantly and negatively correlated with the light transmittance of rice population,while showing a significant and positive correlation with the rate of root bleeding sap.