Agronomic Traits and Grain Quality of Upland Rice Cultivated in Southeast Sulawesi, Indonesia

抄録

Farms in Southeast Sulawesi Province, Indonesia, historically grow upland rice crops that utilize the slash-and-burn farming system. However, little is known about grain quality and the differences between upland rice varieties in this region. In the present study, growth and grain yield were measured to elucidate the characteristics of traditional upland rice varieties grown by local farmers. Additionally, amylose and protein content were measured to understand their characteristics. In this region, farmers predominantly grew traditional rice varieties, which were deemed as tropical japonica based on the measured agronomic traits. These traditional varieties were highly varied in terms of grain appearance and yield-related factors. Grain yield in the traditional varieties (3.0 t ha-1 on average) was inferior to that of Lampung (4.0 t ha-1 on average), an improved variety newly introduced from outside the region. In particular, Lampung tended to have a higher spikelet number per m2 than that of the traditional varieties. The protein and amylose content varied depending on the different varieties. Amylose content of eleven upland rice varieties was determined, with eight varieties characterized as sticky rice, two as non-glutinous varieties, and one as an extremely low amylose variety. These results indicate that this region contains valuable upland rice varieties, and this information is useful for future genetic resource studies.