Abstract: In order to identify the quality characteristics of high quality rice varieties and its relationship with leaf photosynthesis，breed and screen new rice varieties with good taste, eight high-quality rice varieties along the Yellow River rice area in Henan province were used as experimental materials under field cultivation. This study measured and analyzed rice amylose content, protein content, processing quality characteristics (brown rice rate, milled rice rate, head rice rate) and appearance quality characteristics (chalky grain rate and chalkiness), and measured the photosynthetic rate of sword leaf in the grain-filling stage. The results showed that the brown rice rate, milled rice rate and head rice rate of eight excellent rice varieties were higher, the coefficient of variation among the varieties was lower. The chalky grain rate and chalkiness varied among rice varieties, and their coefficients of variation among the varieties were 39.73% and 36.49%, respectively. The coefficients of variation of amylose content, protein content and taste value affecting taste qualities of rice were relatively small, less than 5%. The correlation analysis showed that the protein content had a significant left-biased parabolic relationship with the food taste value（r=0.827*）, the straight-chain starch content had a very significant negative correlation with taste value (r=-0.905**). The grain thickness of brown rice had a significant open-down parabolic relationship with the taste value（r=0.747*）. The appearance quality, protein content and taste value were negatively correlated with leaf photosynthetic rate in the middle and late grain filling stage, but positively correlated with amylose content. These results showed that the lower the content of protein and amylose, the better taste quality of rice. The taste quality became better with the increase of grain thickness in a certain range, but decreased with the grain thickness of brown rice exceeding more than 2.1 mm. Increasing the photosynthetic rate of rice leaves in the middle and late grain filling stage could help to improve the appearance and nutritional quality of rice, while the increase of  amylase content led to the reduction of rice taste value. Therefore, the high photosynthetic efficiency of rice leaves had some certain selection pressure in the quality rice breeding. It was of great significance for improving taste quality of rice by reasonably regulating the photosynthetic rate of leaves in the middle and late grain filling stage.

Key words: rice, food taste, amylose, protein, grain thickness, photosynthetic rate

摘要： 为明确优质稻米品质性状及其与叶片光合作用的关系，培育筛选优良食味水稻新品种，以河南省沿黄稻区8个优良食味水稻品种为试验材料，在大田栽培条件下，对稻米的直链淀粉含量、蛋白质含量、加工品质指标（糙米率、精米率和整精米率）和外观品质指标（垩白粒率和垩白度）等性状进行测定和分析，并对籽粒灌浆期水稻剑叶的光合速率进行检测。结果表明，8个供试优良水稻品种的糙米率、精米率和整精米率均较高，品种间的变异系数较低；稻米外观品质垩白粒率和垩白度在品种间差异较大，变异系数分别为39.73%和36.49%；影响稻米食味品质的直链淀粉、蛋白质含量和食味值在品种间变异系数相对较小，均低于5%。相关分析表明，蛋白质含量与食味值呈显著的开口向上的左偏抛物线关系（r=0.827*），直链淀粉含量与食味值呈极显著的直线负相关关系（r=-0.905**），糙米粒厚与食味值呈显著的开口向下的抛物线关系（r=0.747*）；外观品质指标、蛋白质含量和食味值与灌浆中后期的叶片光合速率均呈负相关关系，直链淀粉含量与之呈正相关关系。说明蛋白质和直链淀粉含量越低稻米的食味越好，在一定范围内，随着糙米粒厚的增加食味增加，而糙米粒厚大于2.1 mm，食味值反而下降；提高水稻灌浆中、后期叶片的光合速率，有利于改善稻米的外观和营养品质，而稻米直链淀粉含量增加，食味值下降。因此，水稻叶片的高光合效率在优质食味米选育方面存在一定的选择压力，合理调控水稻中后期叶片的光合速率对提高和改善稻米食味品质具有重要意义。

关键词: 水稻, 食味, 直链淀粉, 蛋白质, 粒厚, 光合速率