短期NaHCO3胁迫对3种冷季型草坪草生理生态特征的影响

土壤盐渍化严重威胁草坪草的可持续发展,选育和种植耐盐草坪草可改良和利用大面积盐渍土壤。以3种冷季型草坪草黑麦草(Lolium perenne L.)、高羊茅(Festuca arundinacea L.)和早熟禾(Poa pratensis L.)为试验材料,采用盆栽法研究不同浓度NaHCO3胁迫(0,0.2%,0.4%,0.6%,0.8%,1.0%)对3种冷季型草坪草生理生态特征的影响。结果表明:不同浓度NaHCO3胁迫下3种冷季型草坪草草坪外观质量、叶片萎蔫系数、叶片相对含水量、叶片叶绿素含量和K+含量均随着NaHCO3浓度的增加而逐渐降低,且浓度越高,下降越明显;0.4%～1.0%NaHCO3胁迫降低了3种冷季型草坪草的地上部分和根系干重,且随着NaHCO3浓度的增加,生长受到胁迫的抑制程度显著增大,根系部分的受抑制程度比地上部分更明显;不同浓度NaHCO3胁迫下3种冷季型草坪草叶片相对电导率、脯氨酸含量、丙二醛含量和Na+含量随着NaHCO3胁迫浓度的升高呈上升趋势,且浓度越高上升越明显;NaHCO3浓度0.4%时,3种冷季型草坪草已受到伤害;黑麦草、高羊茅和早熟禾在不同浓度NaHCO3胁迫下的隶属函数平均值均表现为早熟禾黑麦草高羊茅,说明3种冷季型草坪草抗NaHCO3胁迫的能力均为早熟禾强于黑麦草和高羊茅。

Effects of Short-term NaHCO3 Stress on Physiological and Ecological Characteristics of Three Cold-season Turfgrass Species

Soil salinization is a serious threat to the sustainable development of turfgrass, and breeding and planting salt-tolerant turfgrass can improve and utilize large area of saline soil. The effects of NaHCO₃ stress at different concentrations (0, 0.2%, 0.4%, 0.6%, 0.8% and 1.0%) on the physiological and ecological characteristics of three types of cold-season turfgrass, including ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea L.) and kentucky bluegrass (Poa pratensis L.) were studied by pot experiment. The results showed that the turf quality, leaf wilting score, leaf relative water content, leaf chlorophyll content and K⁺ content of the three types of cold-season turfgrass decreased with the increasing of NaHCO₃ concentration, and the higher the concentration, the more obvious the decrease. Dry weight of aboveground and roots of the three types of cold-season turfgrass reduced under 0.4%~1.0% NaHCO₃ stress, and with the increasing of NaHCO₃ concentration, the inhibition degree of growth increased significantly, and the inhibition degree of root system was more obvious than that of aboveground parts. The leaf relative conductivity, proline content, malondialdehyde content and Na⁺ content showed an increasing trend with the increasing of NaHCO₃ stress concentration, and the higher the concentration, the more obvious the increase. When NaHCO₃ concentration was greater than 0.4%, three types of cold-season turfgrass were damaged. The average value of subordinate function under different concentrations of NaHCO₃ stress followed the order of kentucky bluegrass > ryegrass > tall fescue, indicating that the resistance of kentucky bluegrass to NaHCO₃ stress was stronger than that of ryegrass and tall fescue.