Abstract: Lawn grasses play an increasing role in urban greening and environment conservation.Shade tolerance is a particularly serious problem for lawn grasses resulting from tall city buildings.Tall fescue and Kentucky bluegrass are two main cool-season lawn grasses.The technology of improving shade tolerance of lawn grasses are discussed in this paper.Both lawn grasses under 57% shade stress are treated using ABA,sucrose and silicon.Each treatment includes four difference concentrations(ABA: 0,0.02,0.06,0.10 mmol·L^-1,sucrose: 0,600,800,1000 mg·L^-1,silicon: 0,0.50,1.00,1.50 mmol·L^-1).Results indicate that ABA is not suitable for enhancing shade tolerance of either lawn grasses,but both sucrose and silicon can promote shade tolerance for both lawn grasses.The best concentration of sucrose is 800 mg·L^-1 for tall fescue and 600 mg·L^-1 for Kentucky bluegrass.The best concentration of silicon is 0.50 mmol·L^-1 for tall fescue and 1.50 mmol·L^-1 for Kentucky bluegrass.

Key words: Tall fescue, Kentucky bluegrass, Shade tolerance, ABA, Sucrose, Silicon

摘要： 为探索外源物质对草坪草耐荫性的作用效果及其最佳浓度,在57%遮荫胁迫下,选用脱落酸(ABA)(0,0.02,0.06和0.10mmol·L^-1)、蔗糖(0,600,800和1000mg·L^-1)和硅酸钠(0,0.50,1.00和1.50mmol·L^-1)对盆栽高羊茅(Festuca arundinacea)和草地早熟禾(Poa pretensis)进行处理。结果表明:各浓度ABA对提高2种草坪草耐荫性没有效果,反而加重胁迫,明显抑制植株的生长,严重影响草坪外观质量;适宜浓度的蔗糖和硅酸钠能不同程度的促进2种草坪草的生长,提高其耐荫性;800mg·L^-1蔗糖和0.50mmol·L^-1硅酸钠对高羊茅处理效果最佳,600mg·L^-1蔗糖和1.50mmol·L^-1硅酸钠对草地早熟禾处理效果最佳。

关键词: 高羊茅, 草地早熟禾, 耐荫性, 脱落酸, 蔗糖, 硅