粳稻直立穗型基因对稻米品质的影响

Effects of Erect Panicle Type Gene of Japonica Rice on Rice Quality

选用直立穗型近等基因系作为材料,研究了粳稻直立穗型基因对米质性状的影响。结果表明,直立穗型基因对碾米品质和外观品质有负面影响,它使整精米率明显下降,垩白粒率和垩白度明显增加,外观品质变劣;但直立穗型基因对蒸煮食味品质有正面影响,虽然一定程度上降低了直链淀粉含量和胶稠度,但却显著增加了食味值;对营养品质的影响主要表现在显著降低了总蛋白和谷蛋白含量,增加了清蛋白、球蛋白和醇溶蛋白含量;对淀粉RVA谱特征值的影响不大,只是使冷胶黏度和消减值有所增加,峰值黏度、热浆黏度和崩解值变化不大。整精米率、直链淀粉含量、谷蛋白含量、总蛋白含量和淀粉冷胶黏度等米质指标在直立穗型内不同粒位间变异较大,而垩白粒率、垩白度、食味值、胶稠度和淀粉消减值等米质指标在弯曲穗型内不同粒位间变异较大。直立穗型品种着粒密度大和二次粒率高可能是近等系间某些米质指标相差较大的主要原因。

The near isogenic lines （ NILs） with erect panicle type gene were used to study effects of the japonica erect panicle type gene on rice quality traits .Results showed that erect panicle type gene had negative effect on mill -ing quality and appearance quality , it made the head rice percentage decrease obviously , chalky grain percentage , chalkiness degree increase significantly ,appearance quality worse .But erect panicle type gene had a positive effect on cooking and eating quality .It made amylose content and gel consistence decrease to a certain extent ,taste quality in-crease significantly .Effects of erect panicle type gene on the nutritional quality were mainly manifested in reducing significantly the content of total protein and glutelin ,increasing the content of albumin ,globulin and prolamin .Effects of erect panicle type gene on RVA profile characteristics values were not big ,it only made cool paste viscosity and set-back increase .Variations of quality indexes such as head rice percentage ,amylose content ,glutelin content ,total pro-tein content and cool paste viscosity was larger among different grain position within erect panicle cultivars .Variations of quality indexes such as chalky grain percentage ,chalkiness degree ,taste quality and gel consistence was larger a-mong different grains within curved panicle cultivars .The main reason of the large difference in some rice qualitative indexes among NILs may be higher grain density and higher ratio of secondary branch grains and total grains .