再生稻穗茎比与产量及其构成因素的关系

Relationships of panicle to stem ratio with yield and its components of ratoon rice

【目的】探析再生稻穗茎比与产量及其构成因素的关系,确立高效准确的再生力鉴定指标,为再生稻高产育种与栽培提供参考。【方法】田间试验于2016年和2017年在福建省三明市尤溪县再生稻试验示范基地开展,以7个生育期相近的强再生力杂交稻品种为材料,设置3个试验重复,采用完全随机区组设计。试验测定指标包括头季和再生季水稻的有效穗数、穗粒数、结实率、千粒质量、产量、穗茎比,计算颖花量、库容量、日产量和热能利用率。通过主要性状间的相关、回归与通径分析,定量研究决定再生力的关键因子。【结果】(1)有效穗数和穗茎比对再生稻产量起决定作用,有效穗数多、穗茎比大,则热能利用率、日产量和产量较高。(2)通过颖花量和库容量的作用,穗粒数对头季产量贡献最大,而有效穗数对再生季产量的贡献最大,因此选择头季大穗重穗和再生季多穗特征的品种,有利形成颖花量和库容量优势,易获高产。(3)再生季有效穗数、穗粒数、结实率、千粒质量这4个性状均与产量相关极显著,对产量的贡献率分别为35.40%,17.03%,25.19%和20.52%,均为影响再生力的主要因子。穗茎比与再生季产量关系最密切,相关系数达0.8619,与有效穗数、结实率极显著相关,与穗粒数显著相关,穗茎比可作为鉴定再生力的关键指标,预测再生季产量的平均精度达90.10%。(4)以穗茎比为指标,杂交稻品种再生力可分为4级,再生季水稻产量达3750 kg/hm^(2)以上品种的库容特征:穗茎比≥1.1761,有效穗数≥330.24穗/m^(2),穗粒数≥63.89,结实率≥82.25%,千粒质量≥27.60 g。(5)选择杂交稻组合头季产量满足高产要求的前提下,品种再生力越强、穗茎比越高,再生季产量也越高,将间接指标穗茎比和直接指标产量相结合,经再生力鉴定,筛选出福优366和福两优366适合作再生稻栽培的优良新组合。【结论】头季和再生季的增产因素分别是穗粒数和有效穗数,穗茎比可作为高效鉴定再生力的共性指标,头季大穗重穗、再生季多穗是再生稻品种总体高产的重要特征。

【Objective】The relationships of panicle to stem ratio with yield and its components of ratoon rice were studied and efficient and accurate identification of regeneration capacity was conducted to provide basis for improvement of high yield breeding and cultivation of ratoon rice.【Method】The field experiment was conducted on the experimental demonstrative base for ratoon rice at Youxi,Fujian in 2016 and 2017.Seven hybrid rice varieties with similar growth period and high regeneration capacity were planted with a completely random block design for three replications.The effective panicle number,spikelet per panicle,thousand grain weight,seed setting rate,and panicle to stem ratio were determined and spikelets,storage capacity,daily grain yield and heat utilization efficiency of grain of the first season and ratoon season rice were deducted.The key factors of regeneration capacity were analyzed through variance,correlation,regression and path analysis.【Result】(1)The number of effective panicle and panicle to stem ratio affected yield of ratoon rice decisively.The varieties with more effective panicle and higher panicle to stem ratio had higher heat utilization efficiency,daily grain yield and yield.(2)The grain number per panicle contributed the most to yield of the first season rice,and effective panicle number contributed the most to yield of ratoon season rice through the effects of spikelets and storage capacity.The hybrid rice cultivars with heavy or large panicles from first season and more panicles from ratoon season were the best for high yield.(3)The panicle to stem ratio,effective panicle,seed setting rate and spikelets per panicle had extremely significant relationships with yield and their contributions were 35.40%,17.03%,25.19%and 20.52%,respectively.The panicle to stem ratio had the closest relationship with coefficient of 0.8619 and it could be used as a key index of regeneration capacity with prediction accuracy of 90.10%.(4)The regeneration capacity could be divided into 4 stages using panicle to stem ratio as index.Varieties with yield of over 3750 kg/hm^(2)had sink traits of panicle to stem ratio≥1.1761,effective panicle number≥330.24 per m^(2),spikelets≥63.89 per panicle,seed setting rate≥82.25%and thousand grain weight≥27.60 g.(5)Satisfying high yield requirements of first season of hybrid rice combination,stronger regeneration capacity had larger panicle to stem ratio and higher yield.Fuyou 366 and Fuliangyou 366 were identified as superior varieties for breeding hybrids with high ratoon ability.【Conclusion】The yield increasing factors of first-season and ratoon season rice were spikelets per panicle and effective panicles,respectively.The panicle to stem ratio can be used as a general evaluation index for regeneration capacity.The key characteristics for high yield of ratoon season rice included heavy or large panicles for the first-season rice and more panicles for ratoon season rice.