Abstract: 【Method】Using 15 indica rice varieties with different panicle weight, some plant type characteristics in heavy panicle type of hybrid rice (HPT) and their relation to yield and its components were studied. 【Result】The leaf area index (LAI) of HPT varieties was lower than that of medium panicle type (MPT) and light panicle type (LPT) varieties, but its decreasing rate of LAI and efficient LAI after heading was slower and had much higher percentage of efficient LAI, specific leaf weight and ratio of grain to leaf area (cm2) in comparison with MPT and LPT varieties. The length, width, thickness and area of top 3 leaves of HPT varieties were significant larger than those of MPT and LPT varieties, and these components of top 3 leaves were significantly and positively correlated with the number of spikelets and filled grains, grain weight per panicle and grain yield. The flag leaf in HPT varieties was erect with sorrow leaf angle, and their leaf angle of 2nd and 3rd leaf from top increased in sequence. The plant height of HPT varieties were higher than that of MPT and LPT varieties, and their leaf site of top 3 leaves also increased in sequence. Therefore, HPT varieties had an ideal plant type and could increase the utilization efficiency of sunlight energy. 【Conclusion】The ideal plant type characteristics and their adjuncts for HPT varieties were proposed in this paper.

Key words: Heavy panicle type, Rice, Plant types