| 摘要: |
| 【目的】探析再生稻产量与植株性状间的关系，为适宜轻简栽培再生稻品种的选育和筛选以及高产栽培提供理论与实践依据。【方法】田间试验于2018年在福建省三明市尤溪县再生稻试验示范基地进行，以５个重穗型强再生力杂交稻品种为材料，采用轻简栽培方式，设置3个重复，完全随机区组设计。考查农艺及穗部性状，测定并计算SPAD值衰减指数、再生芽出鞘率、热能利用率和日产量。通过相关、回归与通径分析，研究再生稻产量构成与形成特点，解析性状指标与产量及产量构成因素的关系，进而确定再生力关键因子。【结果】轻简栽培方式下，再生稻产量构成因素中，有效穗数受千粒质量、结实率和颖花量间接作用的累加效应，对产量贡献最大，因而增加有效穗数是提高再生稻产量的重要途径。再生稻产量与头季稻株高、结实率、千粒质量呈极显著正相关关系，相关系数分别达0.63,0.54,0.65，说明筛选和选育再生力强、植株高度适宜、生产量大的高结实重穗型杂交稻品种是保障头季稻和再生稻产量的前提。SPAD值衰减指数与再生稻产量间相关性达极显著水平，相关系数为-0.82，其偏相关系数也达极显著水平，可作为衡量再生稻品种产量高低的关键指标。1周、2周再生芽出鞘率与产量间均呈极显著正相关，相关系数分别为0.85和0.83，决定系数均达68%以上，是决定再生力的关键因子。日产量和热能利用率由两季总产间接计算而来，与再生稻产量间相关性极显著，可作为再生稻品种筛选的关键指标。所建产量模拟模型对再生稻产量的预测精度均达85%以上。【结论】轻简栽培方式下再生稻的增产因素是有效穗数，促进腋芽的萌发成苗是再生稻高产增产的关键。不同时期鉴定再生力的关键筛选指标分别为前期头季稻的SPAD值衰减指数、中期再生稻的再生芽出鞘率，以及收获后期的日产量和热量利用率,所建产量模型预测精度较高。 |
| 关键词: 水稻育种 再生稻 植株再生力 产量形成 轻简栽培 |
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| 基金项目:福建省省属公益类科研院所基本科研专项“强再生力水稻新种质创制与新品种培育”(2016R1020-4)；国家重点研发计划资助项目“水稻优质高效品种筛选及其配套栽培技术”（2016YFD0300508） |
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| Yield formation and key screening indicators ratooning rice under simplified cultivation |
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LIN Qiang,WANG Yingheng,LIN Qi,et al
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| Abstract: |
| 【Objective】The relationships between agricultural traits and yield of ratooning rice were studied to provide basis for breeding and screening of ratooning rice varieties suitable for simplified cultivation and application of high yield cultivation technology.【Method】The field experiment was conducted on the experimental demonstrative base for ratooning rice at Youxi,Fujian in 2018.Five heavy panicle hybrid rice varieties with strong ratooning ability were planted in a simplified cultivation system with a completely random block design for three repeats.The agronomic and panicle traits,index for SPAD decay,ratio of ratooning bud number to total stems number,heat utilization efficiency of grain and daily grain yield were deducted.Then correlation analysis,regression and path analysis were used to study the characteristics of yield components and formation for ratooning rice,analyze the relationship between yield and yield components,and identify the key traits for ratooning ability.【Result】The combined effects of thousand grain weight,seed setting rate and spikelet number had the largest positive effect on yield under simplified cultivation,indicating that increasing effective panicle number was an important approach to increase the yield of ratooning rice.The plant height (P<0.01,r=0.63),seed setting rate (P<0.01,r=0.54) and thousand grain weight (P<0.01,r=0.65) for main crop season had positive correlations with the yield of ratooning rice.Those results showed that strong ratooning ability,suitable plant height and high yield of main crop were important factors to ensure the yield of main crop and ratooning rice.The SPAD decay index and yield of ratooning rice was negatively correlated (P<0.01,r=-0.82),and the partial correlation coefficient was also significant (P<0.01).Thus,it could be used as a key trait to forecast the yield of ratooning rice.The ratio of ratooning bud number to total stem number at the 7th and 14th days after harvest were positively correlated with the yield of ratooning rice (P<0.01,r=0.85 and 0.83) with coefficient of determination higher than 68%,and both of them were key factors for ratooning ability.The daily grain yield and heat utilization efficiency of grain calculated based on total yield of main crop and ratooning rice were correlated with the yield of ratooning rice (P<0.01),and they can be used as key factors for identifying ratooning ability.According to the yield simulation model derived from these indexes,the prediction accuracy of the ratooning rice yield were higher than 85%.【Conclusion】Increasing the effective panicle number was important for yield improvement of ratooning rice under simplified cultivation,and the key factor was to promote the development of sprouting buds.The key factors for identifying ratooning ability at different stages were SPAD decay index at early main crop season,ratio of ratooning bud number to total stem number in middle ratooning rice season,and daily grain yield and heat utilization efficiency of grain in the late season after harvest,and the established prediction model of yield has higher precision. |
| Key words: rice breeding ratooning rice plant regeneration yield formation simplified cultivation |
