土培草坪植物对外源铈的生态响应特征

Ecological Responses of Turfgrass to Cerium Nitrate under Soil Cultivation

探讨了外源铈对黑麦草和高羊茅两种草坪植物种子萌发和初期生长的影响,结果表明,在培养土壤中施加一定量的硝酸铈有助于提高草坪植物的种子活力和发芽指数,当硝酸铈的施加浓度为400mg.kg-1时效果最好,其中黑麦草和高羊茅种子活力分别比对照提高了23.1%和42.1%,发芽指数分别提高了18.7%和29.4%。当硝酸铈的浓度为400mg.kg-1时,黑麦草的叶绿素含量和地上生物量为最高,分别高出对照20.6%和16.4%。当硝酸铈的浓度为200mg.kg-1时,高羊茅的叶绿素含量和地上生物量为最高,分别高出对照46.7%和15.4%。硝酸铈能明显增加黑麦草和高羊茅的根长、根干重、须根数和根冠比,这些都有利于提高草坪植物的抗旱性。

Lolium perenne L. and Festuca anmdinacea L. were cultivated with cerium addition in the soil medium. Effects of cerium on seed germination and seedling growth of two turfgrasses were investigated. The results showed that cerium nitrate could promote seed germination and seedling growth of two turfgrasses. The seed vigor and germination index of two turfgrasses reached the maximum at Ce 400mg·kg^-1, and the vigor indices of L. perenne and F. anmdinacea were enhanced by 23.1% and 42.1%, respectively as compared with control; and the germination index of the two turfgrasses increased by 18.7 % and 29.4%, respectively. The chlorophyll content and abovegrotmd biomass of L. perenne were the highest when cerium nitrate concentration was 400mg· kg^-1, increased 20.6% and 16.4% ,respectively as compared with control; but the optimum concentration for the chlorophyll content and aboveground biomass of F. anmdinacea was 200mg·kg^- 1, the chlorophyll content and abovegrotmd biomass increased by 46.7% and 15.4% ,respectively as compared with control. In addition, cerium nitrate could also promote the root length, root dryweight, fibrous roots and the ratio of root and shoot of L. perenne and F. arundinacea. It is beneficial to enhance drought resistance of turfgrass.