不同土壤深度棉花根系形态变化规律及与矿质元素的关系

【目的】研究不同土壤深度下棉花根系形态变化规律,分析与矿质元素的响应关系,及矿质元素对根系形态的调控作用,为构建合理棉花根系构型提供理论依据。【方法】测试37份棉花品种的根系长度、根系表面积、根系体积、根系生物量、根系氮、磷、钾元素,根据公式计算比根长、比根面积、比根体积、根系密度,研究矿质元素对根系形态的调控关系。【结果】位于0~10 cm土壤中,由于氮素作用,促使比根长、比根面积、比根体积增加,轻微抑制根系密度生长。在10~20 cm土壤中,氮素促使比根长、比根面积增加,抑制根系密度的生长及比根体积的增加。在20~30 cm土壤中,氮素对比根长、比根面积、根系密度的作用效果不明显,而对比根体积表现为负相关关系。在30~50 cm土壤中,氮素对比根长、比根面积、比根体积、根系密度表现为正相关关系。在50~60 cm的土壤中,比根长、比根面积、比根体积、根系密度表现为负相关关系。第一主成分与氮素、比根长、比根面积、比根体积的相关性较高,第二主成分主要与根系密度的相关性较高,第三主成分主要与磷、钾元素的相关性较高。磷、钾元素与第一主成分的相关性较高,氮素与第三主成分的相关性较高。【结论】根系在不同土壤深度下,比根长、比根面积、比根体积逐渐增大,单位质量根系含氮量不断减少。根系形态性状主要受氮素调控,磷、钾元素对根系形态性状的调控作用较小。

Changes of Root Morphology and Its Relationship with Mineral Elements in Different Soil Depths of Cotton (Gossypium hirsutum L.)

【Objective】 To study the changes of cotton root morphology and the response to mineral elements in different soil depths and analyze the regulation of mineral elements on root morphology in the hope of providing theoretical support for the construction of reasonable cotton root configuration. 【Method】 The root length, root surface area, root volume, root biomass, root nitrogen, phosphorus, potassium,calcium, magnesium and sulfur of 37 cotton varieties were tested, and according to the formula, the specific root length, specific root area, root volume and root density were calculated. Finally, the regulation and control relationship between mineral elements and root morphology was studied. 【Result】In 0 - 10 cm soil, due to the action of nitrogen, the specific root length, specific root area and specific root volume increased, and the growth of root density was slightly inhibited. In 10-20 cm soil, nitrogen promoted the specific root length, increased the specific root area, and inhibited the growth of root density and the increase of specific root volume. In 20-30 cm soil, the effect of nitrogen on root length, specific root area and root density was not obvious, but the contrastive root volume showed a negative correlation. Nitrogen showed a positive correlation with root length, specific root area, specific root volume, and root density in 30-50 cm soil. In the soil of 50-60 cm, there was a negative correlation between root length, specific root area, and specific root volume and root density. Principal component analysis showed that the correlation between the first principal component and nitrogen element, specific root length, specific root area, and specific volume was higher. The second principal component was more correlated with root density, and the third principal component was mainly related to phosphorus. The correlation between potassium and potassium was high. In addition, the correlation between the phosphorus and potassium elements was higher than that of the first main component, and the correlation between the nitrogen element and the third main component was high. 【Conclusion】 Under different soil depths, the root length, specific root area and specific root volume gradually increased, and the nitrogen content per unit mass root decreased continuously. The root morphological traits were mainly regulated by nitrogen, and the phosphoric and potassium elements had little effect on the regulation of root morphological traits.