本研究 以臺灣、日本、菲律賓、美國、印度、尼泊爾、緬甸、印尼及中國大陸等地區的秈、稉稻栽培品種 100 個，調查穀粒特性、農藝性狀、穗部性狀、米質特性與食味品評，並比較秈、稉稻間的差異。其結果顯示：秈、稉稻在穀粒性狀上有明顯的差異，稉稻穀粒寬廣、粗圓，秈稻則較細長。在農藝特性方面，稉稻較秈稻有較佳的稔實率、較少的一穗穎花數、較短的一次枝梗總長，但在每公分枝梗上的粒數則較秈稻為多。米質方面的調查顯示：秈稻的直鏈澱粉含量較稉稻為高，但為消費需求，參試品種中仍有低直鏈澱粉含量的秈稻及中直鏈澱粉含量的稉稻。而國際稻米研究所近年來培育的新株型品種 ( 系 ) 具有大穗、一穗穎花數多、分蘗少的特性，在稉稻的頻度分布上常位於極端區，可能與其利用大量的爪哇型稻種源有關。

關鍵字： 穗部性狀、稻米品質、秈稻、稉稻、爪哇型稻。

　　 One hundred varieties of japonica and Indica types rice from different sources (Taiwan, Japan, Philippine, USA, India, Nepal, Myanmar, Indonesia, China etc.) were used to study the variance of rice quality and panicle characters. Special emphasis was lied on the comparison of the relationship between Japonica and Indica varieties, and to make use of the interaction for selection of the desirable varieties of rice with high eating quality.

　　The results of experiments are summarized in the followings: Markable differences of grain characters between Indica and Japonica type rice are noted. In general, Japonica rices have broader grain width and round shaped while Indica type rices have slender and longer grains. Japonica type rices generally have a better grain fertility, fewer number of spikelet flowers/ panicle, shorter total primary rachis length. However, they have more grains per cm-rachis than those of Indica type rice. The amylose content of Indica type rices are generally high than that of Japonica type rices. However, there are medium amylose content Indica rice in addition to low amylose Japonica type varieties as the results of rice breeding to meet the demand of the consumers. New strains of rice selected by the International Rice Research Institute to used to have bigger panicle size and more spikelets within a panicle. They are always distributed on the extreme side of the normal distribution of panicle characters. This may be due to the use of big panicle type germplasm from Java in its breeding program.

Key words: panicle characters, rice quality, indica rice, japonica rice, javonica rice.