Difference in calcium speciation in leaves of golden Camellia species from calcareous soil and acidic soil habitats

Abstract

In order to study the calcium speciation characteristics in leaves of golden Camellia species under different habitats, 10 species of golden Camellia from calcareous soil habitats and four species from acidic soil habitats were used as the research objects. The calcium content (Soil-Ca) and pH (Soil-pH) of habitat soil, and the contents of calcium nitrate and calcium chloride (AIC-Ca), water soluble organic acid calcium (H2O-Ca), calcium pectate (NaCl-Ca), calcium phosphate and calcium carbonate (HAC-Ca), calcium oxalate (HCl-Ca), calcium silicate (Res-Ca), and total calcium (Tot-Ca) of leaves were measured. The results were as follows: (1) the Soil-Ca and Soil-pH of calcareous soil were extremely significantly (P<0.01) higher than those of acidic soil. (2) The leaf calcium speciation of golden Camellia species from calcareous soil habitats was primarily HCl-Ca (41.17%), while species from acidic soil habitats was primarily NaCl-Ca (43.10%), and all calcium speciation and total calcium content in leaves of species from calcareous soil were extremely significantly (P<0.01) higher than that from acidic soil except for AIC-Ca and NaCl-Ca. (3) Correlation analysis showed that most of the content of calcium speciation in leaves was extremely significantly (P<0.01) and positively correlated with Soil-Ca and Soil-pH, indicating that soil environment had an important influence on the leaf calcium speciation characteristics of golden Camellia species. (4) According to one-way ANOVA, the content of each leaf calcium speciation was extremely significant (P<0.01) difference among the species in golden Camellia revealing that the calcium speciation characteristics had a considerable variation during the species differentiation. (5) Cluster analysis based on calcium speciation characteristics showed that the 14 species of golden Camellia could be grouped into three categories. In summary, the differences in leaf calcium speciation of plants of golden Camellia species in different habitats may be the consequence of a combination of soil environmental and genetic factors. The results of this study will help to understand the adaptation mechanism of golden Camellia species to soil calcium and provide a reference for the formulation of conservation measures.

Keywords

• golden camellia
• soil environment
• calcium adaptation
• cluster analysis
• karst plant