中文摘要：

以散穗型和密穗型水稻品系为材料,研究穗上不同部位和粒位的粒重及籽粒抗性淀粉含量的差异及其分布特点。结果表明：在稻穗同一部位,一次枝梗籽粒千粒重和抗性淀粉含量高于二次枝梗;一次枝梗籽粒千粒重上部最高,且变异度显著小于中、下部;散穗型水稻中部籽粒的抗性淀粉含量相对较高,密穗型以下部较高;同一枝梗不同粒位间抗性淀粉含量均表现为顶部粒位相对较高,基部粒位较低,千粒重分布则相反。

英文摘要：

Difference in 1 000-grain weight（GW） and resistant starch content（RSC） among the grains at different position and different grains between the loose and compact panicle types were studied.The results showed that the GW and RSC on the primary branches were greater than those on the secondary branches in both types at the same position within a panicle.On the primary branch,the GW of upper grain in a panicle was the greatest,and it had significantly less variation than that of middle and bottom grain;The RSC of middle grain was higher than that of upper and basal grain in loose panicle type rice while that of basal grain was the greatest in compact panicle type rice.On the same branch,the high RSC of different positions appeared at upper grain while low RSC was generally at the bottom grain.On the contrary,the high GW was distributed in the bottom grain.