花后增温对双季优质稻产量和品质的影响

Effect of Post-anthesis Warming on the Grain Yield and Quality of Double-cropped High-quality Rice Cultivars

为明确未来气候变暖对双季优质稻产量和稻米品质的影响,采用开放式主动增温系统,早稻以金早47(常规籼稻)、两优287(杂交籼稻),晚稻以象牙香珍(常规籼稻)、万象优华占(杂交籼稻)和甬优5550(籼粳杂交稻)为试验材料,研究花后增温对双季优质稻产量和稻米品质的影响。结果表明,花后増温(早稻1. 29℃,晚稻1. 73℃)对早晚稻产量均无显著影响。增温条件下,早稻加工品质和垩白粒率均无显著变化,垩白度平均提高了16. 0%;晚稻糙米率、整精米率、垩白粒率和垩白度分别平均提高了1. 8%、3. 5%、30. 3%和27. 2%;早晚稻蛋白质含量平均提高了6. 27%,但直链淀粉含量平均降低了3. 53%,淀粉颗粒的平均粒径提高了0. 09μm。增温对稻米RVA谱特征值的影响在季别和品种间存在较大变异。综上,花后增温对早晚稻产量无显著影响,有利于改善稻米的加工品质和营养品质,但降低了稻米的外观品质。本研究结果为未来气候变暖下双季优质稻的优质丰产栽培提供了理论依据。

To evaluate the response of the grain yield and quality of double-cropped high-quality rice cultivars to climate warming,a free-air temperature increase experiment was conducted with Jinzao47( Inbred Indica rice) and Liangyou287( Hybrid Indica rice) as early rice cultivars,and Xiangyaxiangzhen( Inbred Indica rice),Wanxiangyouhuazhan( Hybrid Indica rice) and Yongyou5550( Indica-Japonica Hybrid rice) as late rice cultivars. The results showed that post-anthesis warming with a canopy temperature increase of 1. 29℃ and 1. 73℃ in the early and late rice growing seasons respectively,had no significant effects on the grain yield of both early and late rice. Post-anthesis warming had no significant effects on the milling quality and chalky grain rate of early rice,but increased the chalkiness by an average of 16. 0%. The brown rice rate,head rice rate,chalky grain rate,and chalkiness of late rice were increased by an average of 1. 8%,3. 5%,30. 3%,and 27. 2%,respectively. Protein content was increased by an average of 6. 27% for both early and late rice under warming,whereas amylose content decreased by 3. 53%,with an increase of 0. 09μm in the average diameter of starch granules. The rice flour RVA characteristics showed a large variation with growing seasons and cultivars under post-anthesis warming. In conclusion,post-anthesis warming had no significant effects on the grain yield of double-cropped high-quality rice cultivars,while benefiting the milling and nutritional quality of rice grains but with a deterioration in the appearance quality. These results shed light on the production of the double-cropped rice for both high quality and high yield in face of climate warming.