Abstract: In order to investigate the tolerance of Ludisia discolor to drought stress, the experiments potted water control to simulate drought were used to study the changes of growth, physiological and biochemical indicators, and bioactive components in L. discolor seedlings with around 6 months of age under different water treatments. The main response factors to drought resistance were evaluated through correlation analysis (CA) and principal component analysis (PA), which would provide some references for the water management under conservation and cultivation of L. discolor. The results showed that with the increase of drought severity, the height of L. discolor seedlings showed a downward trend compared to the control group, but there was no significant effect on stem thickness. The relative water content of leaves decreased, and the content of chloroplast pigment (Chl) first increased and then decreased, while the content of anthocyanin (ACN) showed an upward trend. Under drought stress, the activities of peroxidase (POD) and superoxide dismutase (SOD) showed a trend of first increasing and then decreasing. The contents of malondialdehyde (MDA), soluble sugar (SS), and the bioactive substances such as total flavonoids (TF), total phenols (TP), and polysaccharides (PS) all increased. Through correlation analysis and principal component analysis, it was found that MDA, SS, PS, and relative water content could be used as the preferred evaluation indicators, and in addition, stem thickness and SOD activity could be used as auxiliary indicators for drought resistance evaluation in L. discolor. In summary, the results indicated that moderate drought stress (soil moisture content 50%–55%) could promote the synthesis and accumulation of osmotic regulating substances and bioactive components of L. discolor, At the same time, to improve the quality of L. discolor, it was recommended to carry out short-term severe drought (soil moisture content 15%–20%) before harvest so that the biological activities of L. discolor could be enhanced. These findings had practical guiding significance for cultivation management.

Key words: Ludisia discolor, drought stress, physiological characteristics, biologically active ingredients

摘要： 为探究血叶兰Ludisia discolor对干旱胁迫的耐受性，以炼苗后自然生长约6个月龄的血叶兰组培苗为试材，盆栽控水模拟干旱条件下，分析幼苗生长、生理生化指标及生物活性成分的变化，并通过相关性及主成分分析评价其抗旱性主要响应因子，为血叶兰保育栽培的水分管理提供参考。结果表明，随着干旱程度增加，血叶兰株高较对照组呈下降趋势，但茎粗无明显影响；叶片相对含水量减少，叶绿体色素(Chl)含量先上升后降低，而花色素苷(ACN)含量则呈上升趋势。干旱胁迫下，植株过氧化物酶(POD)、超氧化物歧化酶(SOD)活性均呈先升后降趋势，丙二醛(MDA)、可溶性糖(SS)含量及生物活性物质总黄酮(TF)、总酚(TP)和多糖(PS)含量均增加。相关性分析和主成分分析表明，MDA、可溶性糖、多糖和相对含水量可作为血叶兰耐旱性的首先评价指标，茎粗、SOD活性可为辅助指标。综上，适度干旱胁迫(土壤含水量50%～55%) 可促进血叶兰渗透调节物质、生物活性成分的合成积累，若基于提升血叶兰品质，建议在采收前进行短期的重度干旱(土壤含水量15%～20%)以提升植株生物活性含量，该研究结果对血叶兰栽培管理具有指导意义。

关键词: 血叶兰, 干旱胁迫, 生理特性, 生物活性成分