Abstract: The brown rice thickness and eating quality were investigated by using 71 varieties of northern japonica rice harvested in 2006 as materials. Brown rice thickness varied remarkably in the varieties with a coefficient of variation of 6.57%. The varieties with brown rice thickness from 1.81 mm to 2.10 mm accounted for 78.88% of the total varieties. The brown rice thickness was significantly positively correlated with taste value at 1% probability level. Taste value, protein content, amylose content and RVA viscosity properties of rice grains for five japonica rice varieties were determined following classification based on brown rice thickness with a grain separator. Brown rice thickness had a significant effect on rice quality parameters, such as rice protein content, RVA profile characteristics and taste value. The taste quality was improved with increasing thickness of brown rice for the same variety. Meanwhile the necessity on thickness as an index for breeding was discussed.

Key words: japonica rice, grain thickness, eating quality, starch viscosity

摘要： 以2006年收获的71份北方粳稻主栽品种为试材，研究了糙米粒厚的分布及粒厚与食味品质的相关性。结果表明，品种间糙米粒厚差异较大，变异系数为6.57%，粒厚在1.81~2.10 mm的品种占参试品种总数的78.88％。糙米粒厚与米饭食味评分呈极显著正相关。用粒厚分级机对其中5个粳稻品种进行粒厚分级，测定同一品种不同粒厚样品的米饭食味评分值、蛋白质含量、直链淀粉含量和RVA谱特征值。结果表明，粒厚对稻米蛋白质含量、RVA特征值、米饭食味评分等指标有显著影响，同一品种随着粒厚的增加，食味品质得到改善。讨论了粒厚作为品种选育指标的必要性。

关键词: 粳稻, 粒厚, 食味品质, 淀粉糊化特性