两种地被植物生长及生理指标对盐胁迫的响应

采用盆栽试验法对花叶蔓长春和金叶过路黄进行盐胁迫处理，以了解两种植物的耐盐能力及耐盐性差异。对新梢生长量和相对生长量、叶片中游离脯氨酸（Pro）和丙二醛（MDA）含量、过氧化物酶（POD）和超氧化物歧化酶（SOD）活性等指标进行了测定分析。结果表明：随盐浓度升高，新梢生长量逐渐下降，花叶蔓长春的平均相对生长量高于金叶过路黄；叶片中游离Pro含量增加，MDA含量和SOD活性均呈先升后降趋势，且均表现为金叶过路黄的增幅大于花叶蔓长春；金叶过路黄叶片中的POD活性几乎无变化，而花叶蔓长春中则呈先升后降趋势。综合各测试指标、外部形态观察以及田间生长表现认为：花叶蔓长春的耐盐性较金叶过路黄强，但均可在含盐量为4mg·F^-1以下的土壤中正常生长。

Responses of Two Groundcover Plants to Salt-Stress in Their Growth and Physiological Characteristics

Finca major cv. Variegata and Lysimachia nummularia ＇Aurea＇ grown in pots were studied to tmderstand their salt tolerance and differences when they were treated with NaC1 solutions. Indexes including shoot growth and relative growth increament, free proline and MDA content, POD and SOD activities in the leaves were analyzed in the experiment. The results show that with the increase of salinity, the shoot growth of the two tested plants kept decreasing gradually, the average relative shoot growth of V. major cv. Variegata was higher than that of L. nummularia ＇Aurea＇, the proline content of both species increased, and the MDA content and SOD activities of both species increased at the beginning and decreased afterwards, but the increased range of L. ＇Aurea＇ was wider than that of V. major cv. Variegata, POD activity of L. nummulari ＇Aurea＇ remained almost unchanged in all of the treatments while that of V. major cv. Variegata had a trend to increase firstly and then to decrease. According to the indexes analyzed in the paper and the morphological properties observed in the field, V. major cv. Variegata had a higher salt tolerance ability than L. nummularia ＇Aurea＇ and both species can grow regularly in the soil with salinity under 4 mg· g^-1.