杂交水稻穗上不同粒位籽粒品质性状的差异

Difference in quality characters of the grains at different positions within a hybrid rice panicle

以两系杂交稻两优培九、扬两优6号和103S／郑粳2号及三系杂交稻丰优香占和汕优63为材料，研究稻米整精米率、垩白度和胶稠度在穗上不同部位和不同粒位问的差异及其分布特点。结果表明：整精米率和胶稠度由高到低依次为穗上部、中部、下部枝梗籽粒以及一次枝梗、二次枝梗籽粒；而垩白度则相反。一次枝梗不同粒位籽粒，整精米率和垩白度由小到大依次为第1、第6及第2、3、4、5粒；二次枝梗不同粒位籽粒，整精米率和垩白度由小到大依次为第1、第5及第2、3、4粒；而胶稠度则相反。不同杂交组合粒位问整精米率最大极差变幅为9．57％～14．93％．垩白度为2．71％～9．90％，胶稠度为9．92％～23．47％。

Two-line or three-line system rice hybrids of Liangyoupeijiu, Yangliangyou 6, 103S/Zhenjing 2, Fengyouxianzhan and Shanyou 63 were used as materials, All primary branches on a panicle were evenly divided into three parts of the upper, middle and basal. The grains were numbered as 1 to 6 on a primary branch and 1 to 5 on a secondary branch from the top to base. The difference and distribution characters of head rice （HR）, chalkiness degree （CD） and gel consistence （GC） among the grains at different positions within a rice panicle were investigated. The results showed that grains on the branches at the upper parts of a panicle exhibited the greatest HR and GC, followed by those at the middle part, and those at the basal part the least. For the grains on a primary branch were greater than those on a secondary branch at the ,same part of a panicle. The results were reversed to CD. The order of HR and CD of grain on a primary branch was the grain 1〈 the grain 6〈the grain 2, 3, 4 or 5, the order on a secondary branch was the grain 1〈the grain 5〈the grain 2, 3, or 4. The results were reversed to GC. For the grains at the different positions within a panicle among different combinations, the HR was ranged from 9.57%to 14.93%, the CD from 2.71% to 9.90%, the GC from 9.92% to 23.47%.