Chalkiness characters and scanning electron microscope observation of fragrant rice endosperm

ObjectiveIn order to lay foundation for researching mechanism of grain chalkiness formation and breeding new high-quality fragrant rice varieties,the present study was conducted to investigate relation of chalkiness formation with structure,development and arrangement of endosperm and starch granule for different fragrant rice varieties. MethodField trial was conducted to investigate chalkiness characters such as degree of percentage of grains with chalkiness (PGWC), endosperm chalkiness(DEC) and square of chalky endosperm(SCE) in eleven fragrant rice varieties. In addition,the en-dosperm structures and starch granules of rice grains were also observed by scanning electron microscope (SEM). ResultResults showed that,among eleven fragrant rice varieties,the biggest difference was PGWC,followed by SCE,and the last was DEC. There was proportional relationship between PGWC and DEC. Moreover ,there were some differences in arrange-ment of endosperm cells,distribution of starch granules and among different fragrant rice varieties,which was certainly cor-related with occurrence of chalkiness characters. According to chalkiness location on or within the endosperm ,grain chalk-iness could be divided into sub-types namely white belly,white core and white back among fragrant rice varieties. As for the same fragrant rice variety,there were obvious differences in starch granules of grains between chalky and non-chalky, while there were not obvious differences in starch granules between transparent parts of chalkiness grains and non-chalky grains,and the starch granules developed well in the location with low DEC. ConclusionThe chalkiness formation is closely related to structures, arrangement and development of endosperm and starch granules of different fragrant rice varieties. The results will provide useful references to identify quality of fragrant rice varieties.