Concentration of Ca in the tree body of Shatang mandarin on different rootstocks

【Objective】 The study was to explore the distribution characteristic of calcium concentration in Shatang mandarin trees on different rootstocks.【Method】 Seven-year-old Shatang mandarin trees on sudacih and trifoliate(Poncirus trifoliate) rootstocks were uprooted and divided into 23 parts in mature period and the biomasses and Ca concentrations of different parts were measured.【Result】 The Ca concentration of Shatang mandarin in roots was significantly higher on trifoliate rootstock than that on sudacih rootstock,but the Ca concentrations of other organs were similar in two rootstocks.With the diameter increasing,the Ca concentrations in branches,and their xylem parts decreased but increased in their cortex parts,and the fluctuations in the former two were both higher on trifoliate rootstock than those on sudacih rootstock,and contrary in cortex;both rootstocks were considerably higher in the Ca concentrations of Shatang mandarin in pulp than those in rind,but no differences were found between blades and petioles.With the exception of root crown,the Ca concentrations of Shatang mandarin on both rootstocks in roots followed the order fibrous rootlateral rootmain root,but those in root crown and fibrous root were significantly higher for trifoliate orange than those for sudacih rootstock.【Conclusion】 The types of rootstocks had a significant influence on Ca concentration of Shatang madarin in roots,but little influence on other organs.