0023-6152

AA00697606

24219

Unrefereed

0023-6152

AA00697606

Of the two rice cultivar species, Oryza sativa and O. glaberrima, the former was predicted as a species with a higher potential in growth perenniality compared to the latter in a previous paper. In this paper we made a further study to confirm the specific difference in growth perenniality by comparing the growth characteristics, leaf photosynthesis and photosynthate partitioning in a plant at the post-heading stage. O. glaberrima was characterized by quick accumulation of photosynthate in the panicles. The simple morphological formation of rachis branching of 0. glaberrima is thought to allow the smooth transportation of photosynthate from leaves to chaffs of a panicle and the early maturation. Such a feature as observed in O. glaberrima is regarded as an advantageous character for the seed production in annual plants. The photosynthate partition among different organs was monitored by the ^<13>C trace method. The culm base of O. sativa accumulated several-fold more ^<13>C than that of O. glaberrima. The accumulated photosynthate is available as energy resource for initiation of the regenerative growth by ratooning, and the species having a large amount of the accumulation can keep a high potential of growth perenniality.