3种冷季型草坪草苗期对干旱胁迫的生理响应

为研究昆明地区广泛种植的黑麦草(Lolium perenne)、高羊茅(Festuca arundinacea)和早熟禾(Poa pratensis)幼苗的抗旱性,采用盆栽控水试验方法测定了不同时间干旱胁迫下的草坪外观质量(TQ)、叶片萎蔫系数(LWS)、叶片相对含水量(RWC)、地上部分和根系生物量(Bio)3种草坪草根冠比(RS)、叶片光合速率(Pn)、叶片暗呼吸速率(R)、脯氨酸含量(Pro)、细胞膜透性(RC)以及可溶性糖含量(Sol)等生理生态指标。结果表明:随着干旱胁迫时间的持续,高羊茅的TQ、LWC、RWC、Bio和Pn降低的比例显著低于黑麦草和早熟禾,而R、Pro、RC和Sol的增加量显著高于黑麦草和早熟禾。用隶属函数法对试验测定的9个生理生态指标进行综合评价,3种冷季型草坪草幼苗抗旱性表现为:高羊茅黑麦草早熟禾。

Physiological and ecological responses of three cool-season turfgrasses to drought stress at seedling stage

The study was conducted to estimate the drought tolerance of ryegrass (Lolium perenne ),tall fes-cue (Festuca arundinacea )and Kentucky bluegrass (Poa pratensis )at seedling stage by plot-water control ex-periment.Different physiological and ecological indices including turf quality,leaf wilting score,leaf relative wa-ter content,ratio of root to shoot,leaf photosynthetic rate,leaf dark respiration rate,leaf proline content,relative electrical conductivity rate,and soluble sugar content were measured.The results showed that reduced propor-tion of turf quality,leaf water score,leaf relative water content,aboveground and root biomass,leaf photosynthe-sis of F .arundinacea with the duration of drought stress were lower than L.perenne and P .pratensis ;increased proportion of leaf respiration,leaf proline content,relative electrical conductivity rate,and soluble sugar content of F .arundinacea were higher than others.According to a comprehensive evaluation of 9 physiological and eco-logical indices based on subordinate function of fuzzy mathematics,the order of drought resistance of three cool-season turfgrasses at seedling stage was:F .arundinacea>L.perenne>P .pratensis .