不同株高类型甬优系列籼粳杂交稻产量差异及其形成机理

Yield Difference and Its Formation Mechanism of Indica-japonica Hybrid Rice of Yongyou Series in Different Types of Plant Height

为了探究不同株高类型甬优系列籼粳杂交稻产量差异及其形成机理,以株高S型(株高<135cm)、M型(株高140~150cm)、H型(株高>155cm)甬优系列籼粳杂交稻为试验材料进行2年试验,比较不同株高类型产量及其构成因素、茎蘖动态、干物质积累与转运、叶面积动态、光合势与粒叶比以及冠层结构等特征差异。结果表明,与株高S、H型相比,M型增产21.26%和30.50%,结实率高,千粒重大。有效分蘖临界叶龄期到拔节期,M型茎蘖数增长较为缓慢,拔节后群体茎蘖数下降平缓;抽穗前,M型群体干物质积累量较小,抽穗到成熟期干物质积累量大,达10.51t·hm-2;抽穗至成熟期,M型单茎鞘重呈"V"型变化,最大输出量、最大输出率以及最大转化率均以S型最大,表观输出量、表观输出率、表观转化率均以M型最小;结实期,M型叶面积衰减缓慢,光合势、粒叶比较高。与S、H型相比,M型上3叶长宽大小适宜,叶片受光姿态良好,群体的冠层透光性好。甬优系列籼粳杂交稻株高适宜的M型在较大库容的基础上,依靠合理的冠层结构和较大的叶面积指数,中后期拥有较强的光合物质生产与转运能力,保持库容流的稳定性,促进库容的充实,最终实现高产。本研究结果对籼粳杂交稻株高性状的选育具有重要意义。

In order to study the differences in grain yield and formation mechanism of indica-japonica hybrids of Yongyou series in different plant height types under the high yield cultivation conditions,a field experiment was conducted with short type（ 〈 135cm） including Yongyou1952,Yongyou1956,and Yongyou4395,middle type（ 140 to 150cm）including Yongyou4340, Yongyou4348, and Yongyou4356, high type（ 〉 155cm） including Yongyou4304,Yongyou4306,Yongyou4377,and Yongyou5373. Differences in grain yield and its components,stems and tillers dynamics,dry matter accumulation and translocation,dynamics of leaf area,photosynthetic potential and canopy structure characteristics were analyzed systematically. The two-year results showed that the grain yield of M type was increased by 21. 26% and 30. 50% compared with the types of S and H,which was mainly attributed to its higher seed setting rate and 1 000-grain weight. From the critical stage of productive tillering to jointing stage,growth rate of the stems and tillers of M type was relatively slow,and after the jointing stage,the number of stems and tillers decreased.The dry matter accumulation of M type was small before heading,which reached 10. 51t·hm2from heading to maturing stage. From heading to maturity,the single stem of M type showed ＂V＂shape change and the maximum output,the maximum output rate and the maximum conversion rate of S type was the highest. In addition,the apparent output,the apparent output rate,and the apparent conversion rate from heading to maturity of M type were the smallest. During grain filling,the leaf area of M type decreased slowly,photosynthetic potential and grain-leaf ratio were higher.Compared with S and H types,the width and size of the top three leaves was appropriate,and the posture by light and canopy light transmittance were both great. M type had large storage capacity depending on reasonable canopy structure and large LAI. The production and transport capacity of the photosynthetic material were strong in the middle and later period. At the same time,it kept the stability of flow capacity,promoted the full capacity,and achieved high yield finally. The findings have important significance for breeding plant height of indica-japonica hybrid rice.