RESUMO
This study aims to investigate the effects of different magnesium supply levels on the growth, nutrient absorption and distribution, and quality of Panax quinquefolium, and to determine the optimum content of exchangeable magnesium in soil. Three-year-old plants of P. quinquefolium were used in this study, and eight magnesium supply gradients(CK, Mg1-Mg7) were designed for indoor pot experiment(cultivation in soil). The plant growth indexes, nutrient element content in soil and plant, and root saponin content were determined at the end of the growth period. The correlation analysis of nutrient element content in aboveground and underground parts of P. quinquefolium showed significantly negative correlations of magnesium-calcium, magnesium-potassium, and magne-sium-manganese. With the increase in magnesium supply level, the biological absorption coefficient of magnesium increased, while that of total nitrogen, potassium, iron, and manganese decreased; the biological transfer coefficient of magnesium decreased, while that of nitrogen, phosphorus, calcium, iron, and manganese increased. The saponin content was analyzed by principal component analysis, which showed the comprehensive score in the order of Mg4(2.537), Mg2(1.001), Mg3(0.600), Mg1(0), Mg7(-0.765), CK(-0.825), Mg6(-0.922), and Mg5(-1.663). The partial least squares-path modeling(PLS-PM) showed that the correlation coefficients of exchangeable magnesium and pH with quality were-0.748 and-0.755, respectively, which were significant. Magnesium-calcium, magnesium-potassium, and magnesium-manganese showed antagonism in the nutritional physiology of P. quinquefolium. Excessive application of magnesium can lead to the imbalance of nutrient elements in P. quinquefolium. The content of exchangeable magnesium in soil suitable for the quality formation of P. quinquefolium was 193.34-293.34 mg·kg~(-1). In addition to exchangeable magnesium, pH was also important to the quality formation of P. quinquefolium. Therefore, exchangeable magnesium and pH could be regarded as monitoring factors for the quality formation of P. quinquefolium.
Assuntos
Magnésio , Nutrientes , Panax/química , Fósforo , Solo/químicaRESUMO
Objective: To study the variation patterns of rhizospheric soil nutrient and the content of nutrient elements for Fritillaria taipaiensis,in order to provide the theoretical base for the soil improvement and balanced fertilization during the artificial cultivation. Method: Totally 14 samples of rhizospheric soil of Fritillaria taipaiensis from different origins and years were taken as the research objects. Total N,available N,total P,available P,total K,available K,organic matter,pH and 7 nutrient element contents (Ca,Mg,Na,Mn,Zn,Cu and Ni) were analyzed by the soil agrochemical analysis method combined with the atomic absorption spectrophotometry. SPSS 22.0 software was applied for data multiple comparison and correlation analysis. Result: The all results showed significant differences (PF. taipaiensis. The content of total N,available N,total P,available P and organic matter of rhizospheric soil collected from cultivated varieties decreased with the increase of years,and the content of total K,available K and pH decreased first and then increased. However,the soil physical and chemical properties of wild varieties had no obvious change with the increase of years. The content of Ca,Mg,Na and Cu of soil from cultivated varieties decreased with the increase of years,while the content of Mn decreased first and then increased. And Zn and Ni showed no significant change with the increase of years. Compared with cultivated varieties,the content of Ca,Mg,Na,Mn and Cu increased first and then decreased. The content of Zn and Ni showed no obvious change. In general,the rhizospheric soil nutrient and the content of nutrient elements for wild F. taipaiensis were superior to those of cultivated varieties. Conclusion: The third year is the turning point of F. taipaiensis growth. The rhizospheric soil nutrient and the content of nutrient elements decreased obviously after three years. Attention shall be given to the balanced fertilization,the improvement of soil quality and the prevention of the cropping during cultivation of F. taipaiensis.