Physicochemical properties related to palatability of Chinese japonica-type rice

To obtain basic information for palatability breeding of japonica-type paddy rice in China, we collected 260 varieties from northern area of China, and examined their physicochemical properties (amylose and protein contents of polished rice, breakdown value of polished rice flour and hardness/adhesion ratio of cooked rice). In all physicochemical properties, genetic variation was larger in Chinese rice varieties than in Japanese rice varieties. In Chinese rice varieties, amylose content showed a negative correlation with breakdown value and positive correlation with hardness/adhesion ratio as in Japanese rice varieties. However, the protein content showed a negative correlation with amylose content and positive correlation with breakdown value, in contrast to Japanese rice varieties. Among the 260 varieties examined, Zaoyou3, Liaohui253-2, Jing350 and E35-6 had superior physicochemical properties as in palatable Japanese varieties. These varieties may be useful as parents to breed palatable varieties in China.