两种穗型粳稻穗上不同粒位籽粒几个营养和蒸煮品质性状的比较分析

Comparisons of Several Nutritional and Cooking Qualities of Grains at Different Grain Positions of Panicle between Two Panicle Types of Japonica Rice

选用典型的直立穗型和弯曲穗型粳稻品种,研究了穗上不同粒位籽粒的几个重要营养和蒸煮品质性状差异及其分布特点。结果表明,穗型特征与蛋白质含量、直链淀粉含量和食味值高低无直接必然的联系,但是对穗不同部位间这些指标及其粒位顺序有较大影响。对3个直立穗型品种而言,蛋白质含量、直链淀粉含量表现为穗下部>中部>上部,食味值则相反,而对3个弯曲穗型品种而言,蛋白质含量、直链淀粉含量的表现规律不明显,食味值表现为穗上部>中部>下部;同一稻穗不同枝梗间相比,着生在二次枝梗上的稻米蛋白质含量相对较高、直链淀粉含量和食味值相对较低,而着生在一次枝梗上的稻米蛋白质含量相对较低、直链淀粉含量和食味值相对较高;同一枝梗间的不同着粒部位相比,下部二次枝梗第2、3粒位的蛋白质含量较高、食味值较低,中上部一次枝梗1～6粒位的蛋白质含量较低、食味值较高,而直链淀粉含量在粒位间规律不明显;直立穗型品种单一稻穗不同粒位间的差异大于弯曲穗型品种,其主要原因可能是直立穗型品种着粒密度过大。

Nutritional and taste quality are focused in rice （Oryza sativa L.） breeding for grain quality. Panicle type may have certain effect on grain quality traits. However, research in detail on grain quality difference between/within erect and curved panicle rice is not well-documented. The objective of the present study was to characterize the difference in several nutritional and cooking qualities at different seed positions in japonica rice cultivars which differ in panicle type. Three erect and three curved panicle japonica rice cultivars of similar maturity were grown in randomized block design in 2006. After maturity protein content （PC）, amylose content （AC）, and taste quality （TQ） of milled rice were measured. The results showed that panicle type had considerable influence on PC, AC, and TQ at the different parts of panicle, for erect panicle cultivars, PC and AC increased with the grain position from the upper to the lower parts, while TQ showed reverse trend; for curved panicle ones, PC and AC showed no regular trend, but TQ was the same as that of erect panicle cultivars. In the same panicle, the PC of secondary branches was higher than that of primary branches, while AC and TQ behaved reversely. In the same rachis branches, the 2nd and 3rd grain of secondary branch at lower part had higher PC and lower TQ, the 1st to 6th grains of primary branch at mid and upper part had lower PC and higher TQ, no rule was found for AC at different grain positions of panicle. The difference of referred quality traits at different grain positions in erect panicle was higher than that in curved panicle, resulting from higher grain density in erect panicle. Results from this study will facilitate erect panicle cultivars in rice breeding for quality in Northeast China.