TY - EJOU AU - Kuang, Na AU - Zheng, Huabin AU - Tang, Qiyuan AU - Chen, Yuanwei AU - Wang, Xiaomin AU - Luo, Youyi TI - Amylose Content, Morphology, Crystal Structure, and Thermal Properties of Starch Grains in Main and Ratoon Rice Crops T2 - Phyton-International Journal of Experimental Botany PY - 2021 VL - 90 IS - 4 SN - 1851-5657 AB - Rice ratooning, or the production of a second rice crop from stubble after the harvest of the main crop, is considered to be a green and resource-efficient rice production system. The present study was conducted to examine variance in amylose content (AC), grain morphology, crystal structure, and thermal properties of starch between main- and ratoon-season rice of seven varieties. Ratoon-season rice grains had higher ACs and significantly lower transition gelatinization temperatures (To, Tp, and Tc) than did main-season rice grains. The relative crystallinity and lamellar peak intensity of ratoon-season rice starch were 7.89% and 20.38% lower, respectively, than those of main-season rice starch. In addition, smaller granules with smoother surfaces and lower thermal parameters were observed in the starch of ratoon-season rice. The relative crystallinity and lamellar peak intensity of starch correlated negatively with the AC and positively with transition gelatinization temperatures. These results suggest that the superior cooking quality of ratoon-season rice is attributable to the moderate increase of grain AC, which reduces the relative crystallinity, weakens the crystal structure, and lead to a decrease in the gelatinization temperature. KW - Ratooning rice; starch; amylose content; crystal structure; thermal property DO - 10.32604/phyton.2021.014637