不同栽培条件对杂交晚稻茎秆抗倒伏性状的影响

Influence of different cultivation conditions on stalk lodging resistances of hybrid late rice(Oryza sativa L.)

研究施氮量和栽插密度对水稻茎秆抗倒伏能力的影响及其与茎秆形态性状和力学性状的关系,为水稻抗倒伏高产栽培调控提供依据。以3种不同抗倒伏水平的籼型杂交晚稻品种为材料,设置3个氮水平、3种栽插密度,进行大田试验,研究施氮和栽插密度对水稻茎秆基部节间形态和力学性状的影响及其与倒伏指数的关系。结果表明,随着施氮量和栽插密度的增加,茎秆基部第1节间变细长,第2、3节间长度先增加后下降,茎壁变薄,秆型指数降低,从而提高茎秆的倒伏指数和降低抗倒伏能力;在高氮与高密栽培条件下,水稻的群体大,个体生长受抑制,使水稻植株茎秆的倾斜角度加大,倒伏指数加大,从而使水稻更容易倒伏;水稻基部茎秆的倒伏指数与株高、基部各伸长节间的长度呈正相关,与茎粗、茎壁厚、秆型指数呈负相关;增施氮肥与增加栽插密度,在一定程度上增加了茎长与植株茎秆的弯曲力矩,降低了壁厚、机械强度和折断弯矩(M),从而降低了茎秆的抗倒伏能力,提高了水稻茎秆的倒伏指数(LI)。施纯氮160 kg·hm-2和栽插密度20.0 cm×16.6 cm时,水稻抗倒伏性能较好。

Lodging is one of the important constraints to high yield and stable production of rice. This study investigated the effects of nitrogen and cultivation density application on stem lodging resistance and its relationship with stem morphological and mechanical traits. The mechanisms of stem lodging resistance were explored. Results of the study would provide a theoretical basis for lodging resistance and high yield cultivation of rice. Three indica rice cv.hybrid late rice varieties with different lodging resistance were grown in field experiments conducted with three nitrogen and three cultivation density levels at Shangrao. Lodging index,morphological and mechanical traits of basal culms were measured. Results showed that with the increase of nitrogen fertilizer and plant density,the first stem basal internode became spindling,the second and third internode length showed increasing first and then fall,stemwall became thinning,stem type index decreased,which improved the ability of stem lodging index and reduced lodging resistance; The rice group was large under the cultivation of high nitrogen and density,which inhibited it＇s growth,and increased angle of inclination and lodging index of rice stem leading to easy lodging. The lodging index had positive correlation with plant height,basal elongation internode length and negative correlation with stem diameter,stem thickness,type index; To a certain extent,increasing nitrogen fertilizer and density could increase the stem length and bending moment,reduce the wall thickness,mechanical strength,and bending moment（M）,which reduced the lodging resistance capability,improved rice stem lodging index（LI）. Lodging resistance of rice were stronger under medium nitrogen fertilizer（160 kg·hm-2） and density（20. 0 cm × 16. 6 cm） cultivation condition.