四种鸭跖草科屋顶绿化植物对水分管控的响应

以牛轭草(Murdannia loriformis)、细竹篙草(M. simplex)、假紫万年青(Belosynapsis ciliata)及假紫万年青毛叶变种(B. ciliata var. vilosa)等4种植物为试材，探讨不同屋顶绿化植物在不同水分管理条件下的生长情况以及对干旱胁迫的响应。结果表明，4种植物在浇水周期较短(2 DIW和6 DIW，即每隔2 d和6 d浇一次水)的处理下，其地上部分和根系生物量积累较快，植株根系体量较大，侧根生长较多；而浇水周期较长(10 DIW和15 DIW)的处理减缓植株地上部分及根系生物量的积累；根系形态明显受到控制性浇水管理的影响。非充分浇水管理下(6 DIW和10 DIW)的植株在持续干旱胁迫下表现出较稳定的叶片相对含水量、根系活力和较好的抗旱性，而在频繁浇水管理(2 DIW)和浇水周期较长处理(15 DIW)后，4种植物在持续干旱胁迫下的生理响应都较为剧烈，表现出较差的抗旱能力。因此，在4种鸭跖草科植物建植期间可通过适度浇水(6～10 DIW)，以维持植株较稳定的根系活力和较强的抗旱性。

Effects of Water Control on Drought-resistance of Four Roof Greening Plants of Commelinaceae

Murdannia loriformis, M. simplex, Belosynapsis ciliata and B. ciliata var. vilosa were chose as test materials to discuss and analyse the effects of water regime on the growth and drought-resistance on roof greening plant species in Commelinaceae. The results showed that the 2-day-interval and 6-day-interval watering (DIW) regime produced bigger biomass and root size and more lateral roots than the ones of 10-day and 15-day-intervals. Through a root scanner we could find that root morphology was significantly affected under water regime. The plants under inadequate watering (6 DIW and 10 DIW) maintained more stable relative physiological activities and better drought resistance during the persistent drought period. However, under frequent watering regime (2 DIW) and longer watering regime (15 DIW), the four species under continuous drought stress maintained a poor drought resistance and physiological response. Therefore, appropriate application (6 DIW to 10 DIW) of deficit watering regime may contribute to more stable root dehydrogenase activity and better drought resistance of green roof vegetation of Commelinaceae.