种植密度对蔓性千斤拔种子产量和干物质生产的影响

Effect of Planting Density on Seed Yield and Dry Matter Production of Flemingia philippinensis

【目的】探讨种植密度对蔓性千斤拔种子产量和干物质积累量的影响机制,为蔓性千斤拔高产种子生产提供理论依据和实践指导。【方法】以蔓性千斤拔为试验材料,采用单因素完全区组试验,测定不同种植密度(60万、80万、100万、114.3万株/hm^2,分别记为D1、D2、D3、D4)处理种子产量及产量构成因子和干物质积累量。【结果】种子产量随着种植密度的增加而提高,D4处理种子产量比D1、D2、D3处理分别显著提高19.0%、15.8%和10.3%,但同时导致单株粒数和果荚数显著下降;相关和偏相关分析显示,单株种子产量与单株粒数和果荚数的相关系数分别为0.99和0.988,其偏相关系数分别为0.8858和0.8389,且呈极显著水平;通径分析进一步表明,产量构成因子对单株种子产量直接作用大小表现为单株粒数﹥单株果荚数﹥结实率﹥千粒重,其中单株粒数和果荚数对单株种子产量均有显著的正效应,其贡献率分别为0.5264和0.4661。从物质生产上看,地上部分总的干物质积累量随着种植密度的增加而显著提高,但收获指数呈明显下降趋势;回归分析表明,单位面积的总干物积累量与种子产量、收获指数与单株种子产量均呈显著的线性相关性(R=0.9074和R=0.9880)。【结论】在高密度种植条件下,种子产量提高的原因主要受益于种植密度的显著增加;单株粒数和果荚数是影响单株种子产量的主导因子;提高收获指数和单位面积干物质积累量是蔓性千斤种子产量增加的物质基础。

【Objective】The objective is to explore the effect of planting density on seed yield and dry matter accumulation of Flemingia philippinensis so as to provide atheoretical basis and practical guidance for the production of high-yielding seeds .【Method】The F. philippinensis was used as the test material, and the single-factor complete block test was conducted to determine the effect of different planting densities four different planting density treatments ( 600 000, 800 000, 1 000 000 and 1 143 000 plants/hm2, which were recorded as D1, D2, D3 and D4, respectively) on seed yield, seed components and dry matter accumulation.【Results】The results showed that the seed yield of F. philippinensis increased with the increase of planting density. The highest yield was from the D4 treatment with a panting density of 1 143 000 plants/hm2, which was 1 600.5 kg/hm^2. Compared with the other three treatments, the seed yield of D4 was increased by 19.0%, 15.8% and 10.3% compared with that of D1, D2 and D3, but at the same time, the number of seeds per plant and the number of pods were decreased significantly. Correlation and partial correlation analyses indicated that the correlation coefficients of seed yield per plant with the number of seeds per plant and the number of pods were 0.990 and 0.988, respectively, and the partial correlation coefficients were 0.8858 and 0.8389, respectively, with extremely significant levels. The result of path analysis further indicated that the direct effect of yield components on the seed yield per plant was as follows: number of seeds per plant > number of pods per plant >seed setting rate> 1000-grain weight. The number of seeds per plant and the number of pods had significant positive effects on the seed yield per plant, with a contribution rate of 0.5264 and 0.4661, respectively. From the perspective of dry matter production, the total dry matter accumulation in the above-ground part increased significantly with the increase of planting density, but the harvest index showed a significant downward trend. Regression analysis showed that there was a significant linear correlation between total dry matter accumulation per unit area and seed yield, and between harvest index and seed yield per plant (R=0.9074 and R=0.9880).【Conclusion】In the high-density planting condition, the increase in seed yield is mainly attributed to the significant increase in planting density. The number of seeds per plant and the number of pods were the key factors affecting the seed yield per plant. The increase of harvest index (HI) and dry matter accumulation per unit area was the material basis for the increase of the seed yield of F. philippinensis.