二氧化碳浓度对不育系和可育系水稻颖花关闭的影响_黄友明.pdf

2023，45（2）DOI：10.13836/j.jjau.2023036江西农业大学学报 Acta Agriculturae Universitatis Jiangxiensishttp:/二氧化碳浓度对不育系和可育系水稻颖花关闭的影响黄友明，曾晓春（宜春学院 生命科学与资源环境学院，江西 宜春 336000）摘要：【目的】旨在探索水稻颖花关闭机理，发掘颖花关闭调控新措施。【方法】以可育水稻赣早538、萍恢141、华占和不育系水稻珍汕97A、博优A、岳4A为材料，通过观察离体稻穗刚开放颖花在CO2空气混合气体中的关闭过程，并采用便携式光合仪LCI测定颖花开闭过程中颖花胞间CO2浓度（Ci）、气孔导度（Gs）和蒸腾速率（Tr），研究CO2对水稻颖花关闭的效应。【结果】2%15%CO2处理明显加快可育水稻和不育系水稻颖花关闭进程，极显著缩短颖花开闭历时，明显提高不育系水稻颖花最终关闭率，此效应的最佳浓度为5%。可育水稻颖花Ci、Gs和Tr最大值均出现在内外颖夹角最大时，且均极显著高于内外颖开裂时；不育系水稻颖花Gs和Tr最大值也出现在内外颖夹角最大时，但Ci最大值出现在内外颖合拢时，较可育水稻后置，也均极显著高于内外颖开裂时；较可育水稻，不育系水稻各对应时间点的Ci、Gs和Tr值均明显要低。【结论】提示CO2可能是启动水稻颖花关闭的重要因子，不育水稻颖花关闭进程慢，开闭历时长可能与其Ci最大值后置且偏低有关。关键词：水稻；颖花关闭；二氧化碳；胞间CO2浓度；颖花关闭率中图分类号：S511；S334 文献标志码：A 开放科学（资源服务）标识码（OSID）：文章编号：1000-2286（2023）02-0373-11Influences of Carbon Dioxide Concentration on Spikelet Closure in Fertile and Sterile Rice（Oryza sativa L.）HUANG Youming，ZENG Xiaochun（Department of Life Science and Environmental Resources，Yichun University，Yichun，Jiangxi 336000，China）Abstract：Objective This study aims to explore the mechanism of spikelet closure and discover the new measures to regulate spikelet closure.MethodThe fertile rice Ganzao 538，Pinghui 141，Huazhan and the sterile rice Zhenshan 97A，Boyou A，and Yue 4A were used as materials to study the effects of CO2 on spikelet closure.The closing process of the isolated rice spikelets that just opened in CO2-air mixture were observed，and the intercellular CO2 concentration（Ci），stomatal conductance（Gs），and transpiration rate（Tr）of spikelets were measured by portable photosynthetic instrument（LCI）during the process，to study the effects of CO2 on spikelet closure in rice.Result The results showed that 2%-15%CO2 treatment significantly accelerated the 收稿日期：20220908 修回日期：20221106基金项目：国家自然科学基金项目（31360297）Project supported by the National Natural Science Foundation of China（31360297）作者简介：黄友明，副教授，博士，主要从事作物生理研究，orcid.org/0000-0001-8567-3295，。黄友明，曾晓春.二氧化碳浓度对不育系和可育系水稻颖花关闭的影响 J.江西农业大学学报，2023，45（2）：373-383.HUANG Y M,ZENG X C.Influences of carbon dioxide concentration on spikelet closure in fertile and sterile rice（Oryza sativa L.）J.Acta agriculturae universitatis Jiangxiensis,2023,45(2):373-383.江 西 农 业 大 学 学 报第 45 卷spikelet closing process of fertile and sterile rice，and the time duration from the opening to closing of the glumous flower were shorted significantly，the final spikelet closure rate of sterile rice were increased significantly，and the optimal concentration of this effect was 5%CO2.The maximum values of Ci、Gs and Tr of fertile rice spikelets appeared when the angle between the inner and outer glume was maximum，and the values were significantly higher than that when inner and outer glume cracked.The maximum of Gs and Tr also appeared when the angle between the inner and outer glume was the largest in the sterile rice，but the maximum of Ci appeared when the inner and outer glume were closing and it was significantly higher than its appeared at the time when inner and outer glume cracking and it was later than the fertile rice.The Ci、Gs and Tr in spikelets of the sterile rice were less than that of the fertile rice at the corresponding time points in the process of spikelet opening and closure.Conclusion These results revealed that CO2 may be an important factor in initiating spikelet closure in rice.The spikelet closure of sterile rice was slower and the time from the inner and outer glume cracking to clousure was longer than that of the fertile rice，which may be caused by the maximum of Ci in spikelet was postposition and low level relatively.Keywords：rice（Oryza sativa L.）；spikelet closure；carbon dioxide（CO2）；intercellular CO2 concentration；spikelet closure rate【研究意义】在水稻生产尤其是在杂交水稻制种中，颖花关闭同颖花开放一样是非常重要的过程，都直接影响着水稻种子的产量和质量。水稻抽穗开花期，不可避免地会遭遇各种逆境胁迫，如高温、干旱、雨淋、机械损伤、病害、虫害、盐害和干热风等，严重影响开放颖花的开闭；不育系颖花普遍存在闭颖慢、开闭历时过长、关闭不严、甚至不闭颖等现象。导致结实率降低、裂颖率升高和子房发育异常出现子粒畸形，严重降低种子产量和质量1。通过选择花时相近的不育系和恢复系配组、选育开花习性良好的不育系、采取科学合理的栽培与化学调控技术措施，杂交水稻制种中父母本花时不遇的问题已得到相当程度的解决。然而，水稻杂交制种中不育系开放颖花的关闭障碍又成为目前生产上新的瓶颈和“卡脖子”问题，严重降低杂交种子的产量和杂种质量。因此，研究水稻颖花关闭启动因子、影响因素、关闭机理以及物理化学调控方法势在必行。【前人研究进展】要调控水稻颖花关闭，就必须对颖花开闭运动过程有清晰的认识。水稻颖花开闭和植物气孔开闭类似，都属于膨胀性运动；它们都由细胞的膨压变化引起；在一天的特定时间发生，存在一定的节律性；一定程度上都响应诸如机械损伤、光强或温度的变化等外来刺激2。黄友明等3研究发现，水稻颖花的开闭运动经历了内外颖夹角逐渐增大期（开颖）、内外颖最大夹角保持期（颖花开放）、内外颖夹角逐渐缩小期（闭颖）和内外颖夹角最小期（颖花关闭）4个截然不同的阶段。这种明确的划分可知“开颖”和“闭颖”是既相对独立又互相联系的不同过程。受植物叶片内CO2分压与气孔开闭关系的启发4-5，王忠等6研究发现，水稻成熟颖花开放前，呼吸增强，颖腔内CO2浓度达5%左右。若把稻穗置于5%以上的CO2气体或浸没于pH5.6的CO2水溶液，成熟颖花将迅速开放。由于CO2对花丝伸长、柱头外露、花药开裂及花粉活力均无显著影响，故CO2促进水稻成熟颖花开放技术已应用于杂交水稻制种，能显著提高异交结实率和产量2,7-8。【本研究切入点】成熟颖腔内CO2浓度升高是启动颖花开放的重要因子。然而内外颖开裂后颖腔内CO2浓度迅速降低，颖腔内低浓度CO2是颖花关闭的启动信号吗？如果继续维持颖腔内较高浓度CO2，是否抑制颖花关闭呢？【拟解决的关键问题】在对水稻颖花开闭运动认识以及CO2对成熟颖花开放效应研究的基础上，本文拟开展CO2浓度对水稻颖花关闭影响的研究。1 材料与方法1.1供试材料和试剂以可育水稻赣早538、萍恢141、华占和不育系水稻珍汕97A、博优A、岳4A为材料（均为生产上广泛使用，且不育系材料颖花闭合慢，大量颖花关闭不严，甚至不关闭，裂颖现象非常严重），常规栽培管理于 374第 2 期黄友明等:二氧化碳浓度对不育系和可育系水稻颖花关闭的影响宜春学院基地（地力1级，土壤剖面结构为A-P-W-C，水型为潴育型，粘壤土，电力排灌良好；有机质3.5%，全氮0.22%，有效磷7.6 mg/kg，速效钾96 mg/kg，阳离子交换量19.5 cmol(+)/kg，pH6.8）。CO2空气混合气由盛富莱锐锋气体有限公司提供。1.2处理方法1.2.1处理装置试验装置（图1）由分离式的底座和玻璃罩组成，底座四周设凹槽，能与玻璃罩的4个面缘盖住时相吻合。玻璃罩由厚度为9 mm的普通玻璃制成，长、宽、高分