不同播栽方式下杂交籼稻非结构性碳水化合物与枝梗和颖花形成及产量性状的关系

Relationship of NSC with the Formation of Branches and Spikelets and the Yield Traits of Indica Hybrid Rice in Different Planting Methods

【目的】研究播栽方式对杂交籼稻非结构性碳水化合物(NSC)积累与分配及对枝梗和颖花分化与退化的影响,并探明穗分化期NSC代谢与枝梗及颖花分化与退化的关系及抽穗后NSC积累与产量构成的关系。【方法】在前2年试验的基础上,于2014年采用两因素裂区试验设计,研究了3种播栽方式(机直播、机插和手插)下2个杂交籼稻组合(宜香优2115和F优498)抽穗前和抽穗后植株NSC积累与分配、稻穗不同部位枝梗和颖花分化与退化的规律及差异。【结果】(1)穗分化期NSC的竞争茎鞘较幼穗有明显优势;机插在抽穗期茎鞘贮藏了较多NSC,在籽粒灌浆结实期茎鞘向籽粒高效输送较多的NSC,使其成熟期穗部获得较高的NSC积累量。(2)各播栽方式的枝梗分化及退化差异主要是二次枝梗现存数及退化率、三次枝梗分化数;机插的二次枝梗分化数及现存数、二次颖花分化数及现存数较高,从而有较高的总枝梗数和总颖花数;二次枝梗和一次颖花的退化主要分别发生在穗的下部和上部;二次枝梗分化数和二次颖花退化数均为下部>中部>上部;二次颖花分化数为中部>下部>上部;机插的下部、中部、上部二次颖花现存数均高于手插和机直播;(3)抽穗前12 d和抽穗前4 d及抽穗期茎鞘较高的NSC贮藏量不利于幼穗枝梗和颖花的分化与退化,而抽穗前16 d至抽穗前8 d幼穗NSC积累量与大多数颖花性状呈显著或极显著正相关,是决定大穗形成的关键时期;抽穗后NSC分配主要是通过影响叶片和穗部NSC分配从而影响产量;枝梗及颖花性状与产量关系密切,千粒重和单位面积有效穗均与枝梗及颖花性状呈显著或极显著负相关,而每穗粒数、结实率及产量与枝梗及颖花性状呈显著或极显著正相关;(4)F优498较宜香优2115有更高的茎鞘NSC转运率及对穗部的贡献率,且其大多数枝梗及颖花性状显著或极显著高于宜香优2115,F优498的每穗粒数和结实率极显著高于宜香优2115,相应产量也较高。【结论】不同播栽方式下NSC积累与分配及枝梗和颖花分化与退化有较大差异,且品种间差异较大,机插配合大穗型品种有更高的增产潜力。

【Objective】The objective of this experiment was to explore the effects of planting methods on the accumulation and distribution of non-structural carbohydrates（NSC） and the differentiation and retrogress of branches and spikelets, and to make clear the relationship of NSC in the panicle differentiation stage with differentiation and retrogress of branches and spikelets and therelationship of the accumulation of NSC after heading with yield and its form factors. 【Method】On the basis of the early two year＇s experiments, using a split plot field experiment research was done on the accumulation and distribution of NSC before and after heading, and the regulation and differences of the differentiation and retrogress of branches and spikelets on different parts of panicle which under three planting methods included mechanized direct-seeding（MD）, mechanized transplanting（MT）, and artificial transplanting（HT） of two combinations of indica hybrid rice. 【Result】（1） The stem-sheath had an obvious advantage to the young panicle about the competition of NSC in the panicle differentiation stage. MT garnered more NSC in heading, and transported more NSC to grain with a higher efficiency in the grain filling stage, making it gain more distribution of NSC in maturity.（2） The main differences among these planting methods were in the survived and retrograded percentage of secondary branches and the differentiated third branches. MT had more numbers of the survived and differentiated secondary branches and the survived and differentiated secondary spikelets so that it had more hole branches and spikelets. The retrograde of secondary branches and primary spikelets were respectively concentrated on the lower part and the upper part of panicle. Numbers of secondary branches and secondary spikelets were lower partmiddle partupper part. Numbers of survived secondary spikelets in different parts of panicle of MT were higher than HT and MD.（3） The higher accumulation of NSC in 12 d, 4 d and 0 d before heading were not beneficial to the differentiation and retrogression of branches and spikelets, but the accumulation of young panicle had a significant or extremely significant positive correlation of most characteristics of spikelets in 16 d to 8 d before heading, so this stage was the key stage of forming big panicle. The distribution of NSC after heading was mainly through the effect of the distribution of NSC in leaves and panicle on yield. There was a close contact between the yield and characteristics of the branches and spikelets. Thousand grain weight and effective panicles per unit area had a significant or extremely significant negative correlation of the characteristics of branches and spikelets, numbers of grains per panicle, and the setting percentage and yield had a significant or extremely significant positive correlation with the characteristics of the branches and spikelets.（4） Fyou498 had a higher exportation rate of the NSC of stem-sheath and a higher contribution rate of the NSC of stem-sheath to panicle than Yixiangyou2115, and most characters of branches and spikelets of Fyou498 were significantly or extremely significantly higher than Yixiangyou2115. The number of grains per panicle and the setting percentage of Fyou498 were extremely significantly higher than Yixiangyou2115, so its yield was higher. 【Conclusion】There were large differences of the accumulation and distribution of NSC and the characters of branches and spikelets among different planting methods, and also the varieties. MT cooperates big panicle varieties has a higher yield potential.