杂交粳稻超高产群体的冠层结构特点研究

研究了杂交粳稻超高产群体的苗穗粒结构及干物重在冠层不同层次、不同器官的分布，叶面积配置及光强分布等冠层结构特点．结果表明，杂交粳稻超高产群体冠层总干物重及40cm以下、40～60cm、60～80cm和80cm以上4个层次的干物重分别比常规粳稻高32．29％及29．12％、13．95％、16．45％和100．17％．杂交粳稻叶片(同化器官)与穗(库器官)干重分别占总干物重的248％与12．8％．高于常规稻；而叶鞘与茎(贮藏器官)的干重分别占总干物重的33．6％和28．9％，低于常规粳稻．杂交粳稻超高产群体冠层叶面积配置比较合理，齐穗期40cm以上冠层LAI达5．44．冠层光强上下分布比较均匀，60cm以下冠层光强比常规稻高13．1％～37．0％，而60cm以上冠层光强比常规稻低5．9％～12．2％；20cm、20～40cm、40～60cm和60～80cm各层消光系数分别比常规粳稻低35．1％、13．5％、29．1％和17．2％．

Characteristics of canopy structure of super high yielding Japonica hybrid rice community

In this paper, the characteristics of canopy structure, such as the numbers of seedling, panicle and grain, the distribution of dry matters in different canopy layers and different organs, and the distributions of LAI and of solar radiation in different canopy layers of super high yielding community of japonica hybrid rice were studied, in comparison with normal japonica rice. The results showed that the total the dry matter weight and the dry matter weight of layers below 40 cm, 40-60 cm, 60-80 cm and above 80 cm of japonica hybrid rice canopy were 32.29%, 29.12%, 13.95%, 16.45% and 100.17% higher those that of normal japonica rice, respectively. The ratios of dry leaf (photosynthetic organ) and of dry panicle (sink organ) weight to total dry weight were 24.8% and 12.8%, respectively, which were greater than those of normal japonica rice, while the ratios of dry sheath and stem (storage organs) weight were 33.6% and 28.9%, respectively, which were lower than those of normal japonica rice. The allotment of LAI in different layers of japonica hybrid rice canopy was reasonable, and the LAI of above 40 cm layer at full heading stage reached 5.44. The solar radiation was well-distributed inside japonica hybrid rice canopy, for example, the solar radiation in layers below 60 cm were 13.1%-37.0% higher, but 5.9%-12.2% lower above 60 cm than that of normal japonica rice. The extinction coefficients of solar radiation in layers below 20 cm, 20-40 cm, 40-60 cm and 60-80 cm of japonica hybrid rice canopy were 35.1%, 13.5%, 29.1% and 17.2% lower than that of normal japonica rice, respectively.