大穗型杂交粳稻产量构成因素协同特征及穗部性状

【目的】旨在探讨大穗型杂交粳稻库容构成特征及其穗部性状，探索其群体生产力增长途径。【方法】采用大田试验，以具有代表性的8个大穗型杂交粳稻品种（A18/F7562、A2/F7563、A20/F7501、A5/F9249、A2/F7513、A20/F7503、甬优8号和甬优13号）和2个中等穗型常规粳稻品种（武运粳7号和武粳15）为材料，对大穗型杂交粳稻产量构成特征、群体颖花量、库容量、穗部性状等进行系统的研究。【结果】大穗型杂交粳稻产量、群体颖花量、库容量、穗长、着粒密度、单穗重、每穗一次枝梗数、一次枝梗单枝梗着粒数、每穗一次枝梗总粒数、每穗二次枝梗数、二次枝梗单枝梗着粒数和每穗二次枝梗总粒数显著或极显著高于中等穗型常规粳稻，穗数、结实率、千粒重、一次枝梗结实率和二次枝梗结实率极显著低于中等穗型常规粳稻。随着每穗粒数的增加，大穗型杂交粳稻产量、群体颖花量、库容量和二次枝梗结实率先增后减，穗长、着粒密度、单穗重、每穗一次枝梗数、一次枝梗单枝梗着粒数、每穗一次枝梗总粒数、每穗二次枝梗数、二次枝梗单枝梗着粒数和每穗二次枝梗总粒数不断增加，穗数、结实率、千粒重、一、二次枝梗数比值、一、二次枝梗总粒数比值和一次枝梗结实率不断降低，除产量、库容量和二次枝梗结实率外其它与每穗粒数的相关均达到显著或极显著水平。每穗粒数的提高由中等穗型到偏大穗型，主要依靠一次枝梗的贡献，而由偏大穗型到大穗型以及特大穗型和超大穗型，则主要依靠二次枝梗的贡献。在满足一定穗数和具备稳定的结实率的基础上，提高千粒重，是充分利用大穗型杂交粳稻获取超高产的关键；提高群体颖花量是增加产量的基础，而提高库容量是增加产量的重点，在提高群体颖花量的同时还需兼顾千粒重的稳定。【结论】在本试验条件下，大穗型杂交粳稻每穗粒数250左右时穗粒结构合理，群体颖花量高，库容充实足，产量最理想。随着水稻品种和栽培技术的不断进步，其最适值还将可能更高。

Study on Collaborating Characteristics of Grain Yield Components and Panicle Traits of Large Panicle Hybrid Japonica Rice

【Objective】The objective of this study was to reveal sink components characteristics and panicle traits of large panicle hybrid japonica rice and explore approaches to increase group productivity of it.【Method】A field experiment was conducted with eight representative large panicle hybrid japonica rice varieties(A18/F7562,A2/F7563,A20/F7501,A5/F9249,A2/F7513,A20/F7503,Yongyou 8 and Yongyou 13) and two medium panicle conventional japonica rice varieties(Wuyunjing 7 and Wujing 15) as materials.Grain yield components characteristics,total spikelets,sink and panicle traits of large panicle hybrid japonica rice were analyzed systematically.【Result】Grain yield,total spikelets,sink,panicle length,grain density,grain weight per panicle,No.of branches of primary branches per panicle,grains per branch of primary branches,total grains of primary branches per panicle,No.of branches of secondary branches per panicle,grains per branch of secondary branches and total grains of secondary branches per panicle of large panicle hybrid japonica rice were higher than medium panicle conventional japonica rice significantly,while No.of panicles,seed-setting rate,1000-grain-weight,seed-setting rate of primary branches and seed-setting rate of secondary branches followed an opposite tendency accordingly.With the increasing spikelets per panicle,grain yield,total spikelets,sink and seed-setting rate of secondary branches of large panicle hybrid japonica rice increased firstly and then decreased,while panicle length,grain density,grain weight per panicle,No.of branches of primary branches per panicle,grains per branch of primary branches,total grains of primary branches per panicle,No.of branches of secondary branches per panicle,grains per branch of secondary branches and total grains of secondary branches per panicle followed a growing trend and No.of panicles,seed-setting rate,1000-grain-weight,ratio of No.of branches of primary branches to No.of branches of secondary branches,ratio of total grains of primary branches to total grains of secondary branches and seed-setting rate of primary branches did with a declining tendency accordingly.The others and spikelets per panicle were significantly correlated with the exception of grain yield,sink and seed-setting rate of secondary branches.In order to enlarge spikelets per panicle,it was almost contributed by primary branches from medium panicle to prejudiced large panicle,and secondary branches were the major factors from prejudiced large panicle to large panicle(from large panicle to extra large panicle or from extra large panicle to super large panicle).The increase of 1000-grain-weight was the key point of harvesting super high yield of large panicle hybrid japonica rice on the basis of certain No.of panicles and stabilized seed-setting rate.Increase of total spikelets was the basis of increase of grain yield,while the emphasis was to increase sink.Therefore,stable 1000-grain-weight was needed for increasing total spikelets.【Conclusion】Under the experimental conditions,the applicable spikelets per panicle(250 or so) was the best choice for ideal grain yield and its components with high total spikelets and sink filling for large panicle hybrid japonica rice.With the advancement of breeding and techniques,its optimum would be higher.