不同施氮量和栽插密度下三角形强化栽培杂交稻抗倒伏性与群体质量的关系

Relationship Between Culm Lodging Resistance and Population Quality of Hybrids under Triangle-Planted System of Rice Intensification at Different Nitrogen Application Rates and Planting Densities

以杂交水稻组合Ⅱ优498为材料,在三角形强化栽培(TSRI)条件下,研究了施氮量和栽插密度对水稻群体质量及抗倒伏能力的影响,并探讨了主要群体质量指标与茎秆抗倒伏性及产量间的关系。结果表明,TSRI下,施氮量及栽插密度对水稻产量、群体质量以及茎秆基部各节间抗倒伏能力均存在显著的调控作用。施氮量为150 kg/hm2与栽插规格40 cm×40 cm配合可提高结实期叶面积指数(LAI)、群体透光率,协调茎秆基部各节间弯曲力矩与抗折弯矩,缓和高产栽培的穗粒矛盾,显著提高籽粒产量;而施氮量增加至225 kg/hm2,应适当降低栽插密度,来缓解群体质量指标的恶化,降低倒伏指数,栽插规格50 cm×50 cm为宜。相关性分析表明,不同施氮量和栽插密度下水稻群体质量指标与茎秆基部各节间抗倒伏能力显著或极显著相关;结合产量表现,尤以齐穗期、齐穗后30 d中部的群体透光率以及齐穗后30 d的根系伤流量对水稻产量及抗倒伏性影响显著。

The effects of nitrogen （N） application rate and planting density on population quality and culm lodging resistance of rice were investigated with hybrid rice combination II you 498 as material under triangle-planted system of rice intensification （TSRI） and correlation of population quality with culm lodging resistance and grain yield was ana- lyzed. There was an obvious regulatory effect of N application rate and planting density on grain yield, population quali- ty, and lodging resistance of rice culm under TSRI. Compared with other treatments, 150 kg/hm2 N application rate coupled with the suitable planting density （40 cm X 40 era） improved leaf area index （LAI） and light transmission rate in rice population, coordinated bending moment and breaking resistance of basal internodes, alleviated contradiction of panicle and grain, and increased grain yield. At the nitrogen application rate of 225 kg/hmz , planting density should be reduced to alleviate deterioration of population quality index and decreased lodging index. The suitable planting density was 50 cm X 50 cm. Correlation analysis indicated population quality was significantly correlated with internode lodg ing resistance and yield. Middle part light transmission rate in rice population at full heading and 30 days after full heading, and amount of sap flow of rice root at 30 days after full heading might be indicators for grain yield and culm lodging resistance,