土壤干旱对元宝枫渗透调节能力的影响

Effect of soil drought stress on osmotic adjustment ability of maple leaves

采用盆栽控水法和P-V技术研究分析了不同土壤干旱(速度、程度)条件对元宝枫渗透调节能力的影响。结果表明,元宝枫具有很强的渗透调节能力,但该能力受土壤干旱的速度和程度影响,在缓慢干旱条件下,元宝枫叶片的ψw、ψ0、π100、RWC0、ROWC0均明显降低,其中与渗透调节能力直接相关的(π100可下调0.52MPa,ψ0下调1.51MPa。在快速干旱条件下π100和ψ0分别仅下调0.20MPa和0.48MPa。△π100值也表明缓慢干旱条件下元宝枫渗透调节能力是快速干旱下的45倍。在缓慢干旱条件下,由轻度到中度干旱时其渗透调节能力显著增强(增加270%);由中度到严重干旱时,增加不明显(增加了24.5%)。从3种有机渗透调节物质含量与△π100值的动态变化可见,可溶性糖含量增加对渗透调节能力的贡献是第一位的,其次是Pro、游离氨基酸。

Effect of soil drought stress on the osmotic adjustment ability of maple leaves was studied with one-year-old pot-culture seedling treated by different soil drought gradient and speed. The results showed that maple ( Acer truncatum Bunge) has remarkable osmotic adjustment ability, but the ability was influenced by the soil drought gradient and speed. Under slowly soil drought, ψ_w ,ψ_0,π_(100),RWC^0 and ROWC^0 of the maple leaves descended obviously, and the impotent water parameter ψ_0 and π_(100) descended by 1.51 MPa and 0.52 MPa respectively .But under rapidly soil drought, ψ_0 and π_(100) descended only by 0.48 MPa and 0.20 MPa. The value of △π_(100) under slowly drought was 45 times compared with the value under rapidly drought. Pro,amino acids and sugars were increased under the mild and moderate soil drought, and the relative contribution of the three osmotica to osmotic adjustment was in such a order: sugars>Pro>amino acids.