Breeding Research for Good Appearance Quality of Non-glutinous Rice Grain in Cold Region of Hokkaido in Japan

In Hokkaido, improving appearance quality of non-glutinous rice grain nearly up to those of varieties in the area south of Tohoku district has been the important breeding objective for a long time. For decreasing immature grain such as milky white and white-belly rice so on, increasing whole grain and heightening the whiteness of brown and of milled rice, selections mainly by visual estimation have been used up to the present time. The results was that, in the new and old varieties cultivated after 1903, with the renewal of breeding year, the whole grains were become more and more, and the immature grains, damaged grains and colored grains gradually decreased. In particular, genetically “Yukara” bred in 1961 had extremely more whole grains comparing to varieties bred in, before or the same age. From the pedigree, its excellent characteristics were inherited by many rice varieties bred after “Yukara” with good quality and good taste.The main varieties bred in 1984 and after had rather less whole grain, and had rather more immature kernel than the main brand-name varieties in the area south of Tohoku district. Varieties bred before 1971 had many white-belly rice so on, and in new and old varieties bred lately didn’t have higher whiteness of brown and milled rice. In varieties bred in 1971 and after, varieties bred lately, however, had higher the whiteness of brown and of milled rice, and negative correlation was found between protein content and the whiteness of brown and of milled rice. Although the present main varieties of Hokkaido had lower whiteness of brown rice comparing to main brand-name varieties in the area south of Tohoku district, those varieties of Hokkaido had the same whiteness of milled rice, the same transparency of brown rice, the same transparency of milled rice,and the same whiteness of brown rice especially with only whole grain. Although the present main varieties of Hokkaido had rather more immature kernel and rather less whole grain comparing to main brand-name varieties in the area south of Tohoku district, in grain appearance quality there weren’t clear differences between those varieties of Hokkaido and of the area south of Tohoku district.