Chalkiness Characters and Scanning Electron Microscope Observation of Rice Grain Endosperm of Japonica Varieties in Southern Henan

Chalkiness characters affect not only the grain appearance, milling, eating and cooking qualities but also the grain nutritional quality in rice, thus it is one of the most important traits in rice. It is very important for us to investigate the relation of the chalkiness formation and the development of endosperm structure and starch granule of different rice varieties. Here, we have investigated the chalkiness characters such as chalkiness rate, chalkiness degree and chalkiness area in 15 japonica rice varieties from southern Henan. Furthermore, the endosperm structure and starch granules of rice grain were also observed with scanning electron microscope. The results showed that the 15 japonica varieties have a significantly linear relationship between the chalkiness rate and chalkiness degree. Among the varieties, the biggest difference is the chalkiness rate, the second is the chalkiness area, and the last is the chalkiness degree. Moreover, there is a certain correlation between the distribution of starch granules, the arrangement of endosperm cells and the occurrence of grain chalkiness in the different rice varieties. For the same variety, the starch granules of chalky and non-chalky grains have obvious difference, while the starch granules from the transparent part of chalky rice and non-chalky rice do not have significant difference. The results would provide useful references for the improvement of grain quality in rice.