STUDIES ON THE VARIATION OF GRAIN SPECIFI C-GRAVITY OF INTER-VARIETY AND GRAIN QUALITY IN RICE (ORYZA-SATIVA L)

Four rice varieties, including two Indica (Taichung Sen 3, Taichung Se n 17) and two Japonica (Tainung 70, Taichung 190) type were used to in vestigate the variation of grain specific gravity, as well as the corr elation between the specific gravity and other physical-chemical prope rties of grain quality. The materials were grown at Taichung in the se cond crop of 1989 and the first crop of 1990. Generally, variation of grain specific gravity in second crop was higher than first crop, in a ddition to Tainung 70 has the more uniform tendency in two crops. The data indicated that significantly positive correlation between grain s pecific gravity and amylose content for each variety in first crop, th e gel consistency has the same situation except Taichung Sen 17. It sh owed the negative correlation between grain specific gravity and crude protein content in two crops. The variety of good eating quality, Tai nung 70, showed significantly negative correlation between grain speci fic gravity and hardness, but significantly positive correlation betwe en grain specific gravity and viscousness, balance, adhesiveness of co oked rice. The same as, all of the varieties showed the tendency of po sitive relationship between grain specific gravity and whole kernel (% ), but the negative relationship with broken kernel (%), unmatured ker nel (%) and damaged kernel (%) of brown rice.