Abstract: In order to explore the suitable row spacing and sowing rate ratio for seed production of Agropyron mongolicum in arid and semi-arid areas,a two-factor split-plot design was used in this study. Four row spacing levels (20,30,40,50 cm) and four sowing rates (10,15,20,25 kg·hm^-2) were set up to study the effects of different row spacing and sowing rates on seed yield and yield components of Agropyron mongolicum. The results showed that row spacing had a significant effect on the actual seed yield and potential seed yield of Agropyron mongolicum (P<0.01),sowing rate had a significant effect on the actual seed yield of Agropyron mongolicum (P<0.05),and there was a significant interaction between row spacing and sowing rate on the actual seed yield of Agropyron mongolicum (P<0.01). Multiple regression and path analysis showed that spikelet number,floret number,seed number,panicle length and reproductive branch number had direct effects on seed yield,and the largest contribution to seed yield was reproductive branch number. The regression optimization model analysis showed that the actual seed yield was the highest when the row spacing was 20 cm and the seeding rate was 15 kg·hm^-2. Therefore,it is recommended that the planting spacing should be 20 cm apart and the sowing rate should be 15 kg·hm^-2 in the seed production of Agropyron mongolicum in the arid area of central Ningxia.

Key words: Agropyron mongolicum, Row spacing, Sowing quantity, Seed yield, Regression optimization model

摘要： 为探究干旱半干旱区沙芦草(Agropyron mongolicum)种子生产适宜的行距和播量配比,本试验采用双因素裂区试验设计,分别设4个行距水平(20,30,40,50 cm)和4个播量水平(10,15,20,25 kg·hm^-2),研究了不同行距和播量配比对沙芦草种子产量及产量构成因子的影响。结果表明,行距对沙芦草实际种子产量和理论种子产量有极显著影响(P<0.01),播量对沙芦草实际种子产量有显著影响(P<0.05),行距和播量对沙芦草实际种子产量有极显著的正交互作用(P<0.01)。通径分析表明,小穗数、小花数、种子数、穗长和生殖枝数对种子产量的影响具有直接作用,对种子产量贡献最大的是生殖枝数;回归寻优模型分析得出,当行距为20 cm,播量为15 kg·hm^-2时实际种子产量最高。因此,在宁夏中部干旱区沙芦草种子生产中建议种植密度应为行距为20 cm,播量为15 kg·hm^-2最佳。

关键词: 沙芦草, 行距, 播量, 种子产量, 回归寻优模型