水稻幼穗分化期至抽穗期高温对籽粒形态和充实的影响及其与粒重的关系  

Effect of high temperature during the panicle initiation and heading stages on grain shape and filling and its relationship with grain weight in rice

作　　者：王梦宁 谢可冉 高逖 王飞 任孝俭 熊栋梁[1] 黄见良[1] 彭少兵[1] 崔克辉[1] WANG Meng-Ning;XIE Ke-Ran;GAO Ti;WANG Fei;REN Xiao-Jian;XIONG Dong-Liang;HUANG Jian-Liang;PENG Shao-Bing;CUI Ke-Hui(National Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River,Ministry of Agricultural and Rural Affairs/College of Plant Science and Technology,Huazhong Agricultural University,Wuhan 430070,Hubei,China)

机构地区：[1]作物遗传改良国家重点实验室/农业农村部长江中游作物生理生态与耕作重点实验室/华中农业大学植物科学技术学院,湖北武汉430070

出　　处：《作物学报》2025年第5期1347-1362,共16页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31871541);财政部和农业农村部国家现代农业产业技术体系建设专项(CARS-01)资助。

摘　　要：以热敏感型品种两优培九(LYPJ)和晶两优华占(JLYHZ)、耐热型品种汕优63(SY63)为材料,在盆栽条件下设置幼穗分化期至抽穗期常温和高温2种温度处理,探究幼穗分化期至抽穗期高温对穗分化期颖花和籽粒大小、灌浆期籽粒充实的影响及其与粒重的关系及内在机制。与常温处理相比,幼穗分化期至抽穗期高温导致LYPJ和JLYHZ的千粒重、每穗颖花数、结实率和产量显著降低,但对SY63无显著影响。幼穗分化期至抽穗期高温显著降低LYPJ和JLYHZ颖花和籽粒大小(长度、宽度和厚度), SY63的降幅低于热敏感品种。高温导致LYPJ颖花OsLOGL2基因表达降低、JLYHZ颖花OsCKX5基因表达增加,并显著降低两品种颖花活性细胞分裂素含量。高温对2个热敏感品种成熟期地上部干物质积累无显著影响,显著降低收获指数,降低抽穗期至成熟期单粒增重和平均灌浆速率,对SY63则无显著影响。高温显著降低了LYPJ和JLYHZ籽粒灌浆相关基因(OsFLO2、OsFLO4和OsGIF2)表达和籽粒酸性/中性转化酶、蔗糖合成酶、腺苷二磷酸葡萄糖焦磷酸化酶以及LYPJ籽粒淀粉分支酶活性,对SY63无显著影响。本研究表明幼穗分化期至抽穗期高温降低了收获指数,降低了颖花内源活性细胞分裂素含量从而降低颖花和籽粒大小,也抑制了籽粒灌浆相关基因表达和相关酶活性;因此,高温导致粒重和产量下降可能是由于同化物向籽粒分配减少和库活性受到抑制,表现出高温处理的后续效应。A pot experiment was conducted with two temperature treatments—normal temperature treatment and high temperature treatment during the panicle initiation and heading stages—using three rice varieties:heat-sensitive varieties Liangyoupeijiu(LYPJ)and Jingliangyouhuazhan(JLYHZ),and heat-tolerant variety Shanyou 63(SY63).The objective was to investigate the effects of high temperature during the panicle initiation and heading stages on spikelet and grain size,grain filling,and their relationship with grain weight.Compared to normal temperature,high temperature significantly reduced thousand-grain weight,spikelets per panicle,seed setting rate,and yield in LYPJ and JLYHZ,but had no significant effect on SY63.High temperature also significantly decreased spikelet and grain size(length,width and thickness)in the heat-sensitive varieties,while SY63 exhibited only minor reductions.Additionally,high temperature significantly downregulated the expression of OsLOGL2 in spikelets of LYPJ and upregulated the expression of OsCKX5 in spikelets of JLYHZ,resulting in reduced endogenous active cytokinin levels in spikelets.High temperature decreased the harvest index but had no significant effect on aboveground dry weight at the maturity stage.It also significantly reduced single-grain weight accumulation and the average grain filling rate during the heading and maturity stages in the heat-sensitive varieties,with no significant changes observed in SY63.Furthermore,high temperature treatment significantly reduced the expression of grain filling-related genes(OsFLO2,OsFLO4 and OsGIF2)and the activities of key enzymes involved in grain filling,including acid/neutral invertases,sucrose synthetase,and ADP-glucose pyrophosphorylase,in the heat-sensitive varieties.Starch branching enzyme activity in grains was also significantly reduced in LYPJ,while these enzymes and genes were unaffected in SY63.This study demonstrates that high temperature during the panicle initiation and heading stages reduces the harvest index and decreases spik

关 键 词：水稻 幼穗分化期-抽穗期高温 粒重 籽粒形态 籽粒充实 颖花细胞分裂素含量 

分 类 号：S511[农业科学—作物学]