Difference in Amylose Content Variation of Rice Grains and Its Position Distribution Within a Panicle Between Two Panicle Types of Japonica Cultivars

Under the field conditions, six japonica cultivars with erect panicle and four japonica cultivars with curved panicle were applied to compare the difference in the amylose content (AC) of rice grains and its position distribution in a panicle. Results indicated that the panicle type had a considerable influence on the AC variation of rice grains within a panicle. The cultivars with erect panicle generally had higher variation coefficient, larger dispersing degree and wider variation range of AC than the cultivars with curved panicle, despite it was not significantly related to the AC of cultivar; The AC variation of rice grains within a panicle was closely related to the position of rice grains on the rachis branches, the grains with the relatively low AC often appeared at the bottom or in the middle of the panicle while the grains with the relatively high AC was generally at the top of the panicle. However, more grains with low AC, distributed in the middle of the panicle, could be observed in the cultivars with erect panicle than in the cultivars with curved panicle.