干旱胁迫对不同栽培基质下常春藤光合特性的影响

Effect of Different Cultivation Medium on Photosynthetic Properties of Hedera nepalensis var. sinensis under Drought Stress

夏季水分流失过快是导致垂直绿化植物萎蔫死亡的主要原因,为探讨干旱环境下不同垂直绿化基质对植物光合性能的影响,比较了传统栽培基质、进口无土固态基质保浮科乐(Pafcal),国产无土固态基质炭棉(Tan Mian)的保水性,并以1年生常春藤Hedera nepalensis var.sinensis幼苗为材料,采用自然干燥法控水,测定其在胁迫0 d,10 d,20 d及复水后10 d的气体交换参数、光响应曲线及其特征参数和叶绿素含量变化,探讨常春藤在3种基质中的干旱适应能力。结果显示:(1)传统栽培基质的保水性最好,炭棉次之,保浮科乐最差;(2)在不同程度干旱胁迫下,3种基质中各参数的变化趋势基本一致,但保浮科乐中大部分参数值的变化幅度显著大于传统栽培基质和炭棉;(3)常春藤在传统栽培基质中的总体干旱适应性最强,炭棉次之,保浮科乐最差,这与3种基质的保水性呈完全正相关;(4)在重度胁迫下,保浮科乐中常春藤各指标变化幅度较大,说明常春藤在保浮科乐基质中不能忍受长期的干旱胁迫;(5)复水后,常春藤在传统栽培基质和炭棉中恢复较好,在保浮科乐基质中恢复较差。

Experiments were conducted on comparisons on relative water content of common cultivation medium(pine bark:peat:pearlite:river sand=5:4:0.6:0.4),‘Pafcal’and‘Tan Mian’for 30 days,and on drought stress to 1-year Hedera nepalensis var.sinensis seedlings planted in above-mentioned three medium during July the 1st to 30th 2015.Determinations were implemented on the photosynthetic properties and chlorophyll content in the 0 day(CK),10th day,20th day under drought stress and 10th day after rehydration by air seasoning method.The result showed that relative water content was the highest in common medium,followed by‘Tan Mian’and‘Pafcal’.Photosynthetic parameters of seedling in the tested medium under drought stress had similar variation,however that in‘Pafcal’was significantly larger.H.nepalensis var.sinensis had the strongest drought adaptability in the common medium,followed by‘Tan Mian’and‘Pafcal’,the same order of relative water content.Photosynthetic parameters of seedlings in‘Pafcal’under severe drought stress had larger change,indicating that seedlings could not tolerate long-term drought stress in the medium.After rehydration,seedlings in the common medium and‘Tan Mian’had better recovered than that in‘Pafcal’.