种植模式对高密度下不同耐密性大豆品种根形态的影响

Effect of Planting Patterns on Root Morphology of Soybean Varieties with Different Density Tolerance under High-density Planting

试验以不耐密大豆吉育86和耐密大豆长密豆30为材料,设置2个处理,种植模式处理:垄上双行和垄上单行种植,种植密度处理:20万株/hm^(2)和40万株/hm^(2)。研究耐密性不同的大豆品种的地下根系生理和形态特征以及地上干物质量和产量特性。结果表明,根系活力、根系干重、根长、根表面积、根体积和根尖数分别与大豆产量和地上干物质量存在显著正相关关系。高密度种植显著降低吉育86的干物质量和产量,对于长密豆30的产量虽有降低但未达显著水平。垄上双行对吉育86在高密度条件下的产量提高达显著水平。高密度种植对于不耐密品种吉育86的地下根系和地上冠层造成的竞争抑制程度更高。垄上双行对于不耐密大豆品种根系形态的优化作用,尤其是高密度条件下根系形态的优化效果明显优于耐密大豆。长密豆30地下根系分级结构受种植模式的影响更大,吉育86的地下根系分级结构受种植密度影响更大。综上所述,耐密大豆品种地下根系耐受竞争抑制作用能力更强,高密度条件下具有较强的根系活性响应能力,是耐密大豆品种在高密度条件下保持较高地上部干物质量和产量的重要原因。

The experiment used the soybean variety Jiyu 86 which is not tolerant to dense planting and the soybean variety Changmidou 30 which is tolerant to dense planting as materials.Two treatments were set up in this experiment,one was planting mode treatment:double row planting on ridge and single row planting on ridge,the other one is the planting density treatment:200,000 plants/ha and 400,000 plants/ha.To explore the physiological and morphological characteristics of underground root system and the quality and yield characteristics of above-ground dry matter of soybean varieties with different density tolerance characteristics.The results showed that root activity,root dry weight,root length,root surface area,root volume and root tip number were positively correlated with soybean yield and dry matter,respectively.High density planting significantly decreased the dry matter quality and yield of Jiyu 86,and the yield of Changmidou 30 was decreased but not to a significant level.The yield of Jiyu 86 increased significantly under high density conditions.High-density planting had a higher degree of competition inhibition on the underground root system and above ground canopy of the intolerant variety Jiyu 86.Double row on ridge had obvious optimization effect on root morphology of dense-tolerant soybean varieties,especially under high-density condition,the optimization effect was better than that of dense-tolerant soybean varieties.The underground root hierarchical structure of Changmidou 30 was more affected by planting pattern,and that of Jiyu 86 was more affected by planting density.In summary,the underground roots of dense-tolerant soybean varieties have a better ability to withstand competition inhibition and have a stronger responsiveness to root activity under high-density conditions,which is an important reason for the higher aboveground biomass and yield of dense-tolerant soybean varieties under high-density conditions.