花后不同时段低温对籼粳杂交稻稻米品质性状的影响

【目的】花后低温是影响米质的首要生态因子。为明确花后低温对甬优品种稻米品质性状及淀粉RVA谱特性的影响,【方法】以籼粳杂交稻甬优17号、甬优538和杂交籼稻中浙优1号、常规粳稻浙粳88为材料,采用盆栽试验,通过人工气候箱于水稻花后0-15d(前期)、15-30d(中期)和30d-成熟(后期)分别进行20℃、17℃和14℃的低温处理。【结果】花后低温显著影响供试品种整精米率、垩白度、胶稠度、直链淀粉含量及蛋白质,使甬优品种淀粉RVA谱特征值峰值黏度、热浆黏度、冷胶黏度、崩解值降低,回复值和消减值升高。花后前期低温对稻米加工品质影响最大,而花后中、后期低温对外观品质、蒸煮食味品质和营养品质影响最大,且甬优17号比甬优538对低温更敏感。花后低温对稻米品质影响明显,低温处理影响因品种类型、品质指标及处理时段而异。【结论】生产中应基于品种特性综合考虑稻米各品质指标,在结实期采取相应的米质调优栽培措施,充分发挥籼粳杂交稻品种的品质潜力。

Effect of Low Temperature After Flowering on Grain Quality of indica-japonica Hybrid Rice

【Objective】 The temperature during grain-filling stage of rice is the primary ecologic factor to rice qualities. The research was conducted to reveal the effects of low post-anthesis temperature on rice quality and starch viscosity of Yongyou varieties during grain filling. 【Method】 Four varieties, two indica-japonica hybrid rice (Yongyou538, YY538; Yongyou17,YY17) and two indica rice (Zhongzheyou1, ZZY1) and japonica rice (Zhejing88, ZJ88), were chamber-cultured at temperature as low as 20℃ from 0 to 15 days after flowering(S1), 17℃ from 15 days to 30 days after flowering(S2) and 14 ℃ from 30 days after anthesis to maturity(S3) in a pot experiment. 【Result】 Low temperature after flowering significantly affected the head rice rate, chalkiness, gel consistency, amylose content and protein content of rice, and decreased peak viscosity, hot paste viscosity, cold paste viscosity, breakdown value of Yongyou varieties, and increased setback and consistency. Compared with CK treatment, S1 treatment had the greatest influence on rice processing quality, S2 and S3 treatments had the greatest influence on appearance quality, cooking and eating quality and nutritional quality. Moreover, YY17 is more sensitive to low temperature than YY538. Overall, low temperature after flowering exerted significant impact on grain quality, which varied with genotype, rice quality index and treatment time. 【Conclusion】 The present study indicated that given rice quality indexes differed amony varieties in rice production, we should adopt corresponding measures for high rice quality in grain-filling so as to give the quality potential of indica-japonica hybrid rice into full play.