四种金花茶组植物叶片金属元素含量及富集特性研究

以四种金花茶组植物为研究对象,采用原子吸收光谱法和原子荧光法,测定其嫩叶、老叶及对应土壤中Mg、Ca、Mn、Fe、Zn、Ni、Se、Pb、Cd、Hg、As共11种元素的含量,并分别计算嫩叶和老叶对土壤金属元素的富集系数.结果表明:(1)4种金花茶组植物叶片富含Mg、Ga、Mn、Fe、Zn、Ni等营养元素,各元素在叶片中含量为Ca>Mg>Mn>Fe>Zn>Ni>Se;Pb、Cd、As、Hg等重金属元素含量较低,均达到无公害茶叶标准.(2)老叶和嫩叶中各金属元素含量差异较大,老叶中的Ca、Mn、Fe、Zn、Pb、Cd、Hg、As、Se元素含量均大于嫩叶,尤以Ca、Mn、Fe差异显著;嫩叶中的Mg和Ni含量大于老叶.(3)金花茶组植物对不同金属元素的富集能力不同,对各元素富集能力强弱为Ca、Mn、Mg>Zn、Ni、Hg>Pb、Se>Fe、As,老叶和嫩叶的富集规律存在差异.(4)不同金花茶组植物对金属元素的富集能力有较大差异,龙州金花茶(Camellia longzhouensis)和黄花抱茎茶(C.murauchii)对Mg、Ca、Mn、Zn、Ni、Se、Pb的富集能力均大于金花茶(C.nitidissima)和毛籽金花茶(C.ptilosperma).其中,龙州金花茶对Mg、Mn、Se的富集能力最强,黄花抱茎茶对Ca、Pb、Hg富集能力最强,金花茶对Hg的富集能力较强,对其它元素的富集能力均较弱;毛籽金花茶对Ca、Mn、Ni、Zn的富集能力均最弱.该研究结果为金花茶组植物的进一步开发和利用提供了理论依据.

Enrichment characteristics of metal elements in leaves from four species of yellow flower Camellia

Yellow flower Camellia is one of the world treasure plant resources. In this paper, eleven elements including Mg, Ca, Mn, Fe, Zn, Ni, Se, Pb, Cd, Hg and As were determined in leaves and corresponding soils of four yellow flower Camellia by atomic absorption spectrometry and atomic fluorescence spectrometry, and then the enrichment factors of these metal elements were calculated. The results were as follows:(1)The leaves of four yellow flower Camellia were rich in Mg, Ca, Mn, Fe, Zn, Ni and element contents were Ca > Mg > Mn > Fe > Zn > Ni > Se, while the toxic heavy elements such as Pb, Cd, As and Hg were low, which reached the standards of non-polluted tea.(2)There were obvious differences in metal element contents between young and old leaves. The concentrations of Ca, Mn, Fe, Zn, Pb, Cd, Hg, As and Se in old leaves were higher than those in young leaves, especially in Ca, Mn and Fe, while concentrations of Mg and Ni in young leaves were higher than those in old leaves.(3)Yellow flower Camellia showed different enrichment abilities to different metal elements. The enrichment factors were Ca, Mn, Mg > Zn, Ni, Hg > Pb, Se > Fe, As. Also, the enrichment characteristics were different in young and old leaves.(4)The enrichment abilities of four yellow flower Camellias were different. Overall, C. longzhouensis and C. murauchii had higher enrichment factors of Mg, Ca, Mn, Zn, Ni, Se and Pb than that of C. nitidissima and C. ptilosperma. In detail, C. longzhouensis and C. murauchii showed the highest enrichment of Mg, Mn, Se and Ca, Pb and Hg, respectively. C. nitidissima showed higher enrichment of Hg and lower enrichment of other elements, while C. ptilosperma had the lowest enrichment factors of Ca, Mn, Ni and Zn. The above results showed that plant species, parts and element type had a comprehensive effect on the enrichment factors. The results provide the information for reasonable development and utilization of yellow flower Camellia.