不同栽培介质中茭白对铅胁迫的反应

为研究茭白（Zizania latifolia Turcz.）在不同栽培介质中对重金属Pb²⁺胁迫的反应，以茭白的单季茭品种‘蒋墅茭’和双季茭品种‘葑红早’为试材，采用苇末基质和土壤两种栽培介质进行不同浓度Pb2+的胁迫处理，测定了其生长过程中部分形态、生理指标及其产品器官中Pb²⁺残留含量的变化。结果表明：叶片可溶性蛋白含量、保护酶活性、自顶叶起倒3片功能叶的叶面积及其叶绿素含量及净光合速率等均随Pb²⁺胁迫浓度上升而先上升后下降，脯氨酸含量则逐步增加；苇末基质处理的叶片可溶性蛋白、脯氨酸含量显著低于土壤栽培，而倒3片功能叶的叶面积则显著高于土壤栽培；产品器官肉质茎中的Pb²⁺残留含量较低，苇末基质处理同比均显著低于土壤栽培，表明在苇末基质中栽培茭白具有较高的安全性。

The Response of Zizania latifolia to Lead Stress in Different Cultural Media

To study the response of Zizania latifolia to Pb2+ stress in different cultural medium, a single-harvested cultivar Jiangshu and a double-harvested cultivar Fenghongzao of Zizania latifolia were cultured in reed sediment substrate and soil with different Pb²⁺ concentrations. The changes of some morphological, physiological and biochemical indexes of the Zizania plant and the Pb²⁺ residues in Zizania galls were investigated. The results showed that contents of soluble protein, protective enzyme activities, area and chlorophyll content of functional leaves and net photosynthetic rate ascended under low concentration of Pb²⁺ treatment and descended along with the increase of Pb²⁺ concentrations, while the content of proline ascended all along. Contents of soluble protein and proline were lower but the functional leaf area was higher observably in leaves of plants grown in reed sediment substrate than those in soil in the same concentration of Pb²⁺ stress. The Pb²⁺ residues in Zizania galls were lower than in products of other vegetable. Reed sediment substrate treatments reduced the Pb2+ residues in Zizania galls significantly, comparing with soil treatments. It is implied that the Zizania galls were more secure when cultured in reed sediment substrate.