In the context of increasing global climate change, drought stress greatly affects the growth, yield and quality of medicinal plants. In this study, we analyzed the impact of drought stress on Scutellaria baicalensis Georgi (known as “Huang Qin”) during critical growth stages, emphasizing the necessity for rational irrigation strategies in cultivation amidst global climate change. We conducted a pot experiment with well-watered (CK), leaf-extension stage (LES) drought stress (T1), and seed-ripening stage (SRS) drought stress (T2) treatments. We assessed root morphology, physiology, and active constituent contents at each stage and harvest. The results revealed significant reductions in root dry weight and active constituent yields under drought stress, particularly during the SRS. Compared with that in CK, the root dry weight significantly decreased by 48.87 % and 21.22 % during the LES and SRS, respectively, with SRS stress exhibiting a decrease of 11.43 % compared to LES stress at harvest. Moreover, active constituents like baicalin, baicalein, wogonoside, and wogonin also experienced significant yield reductions in T1 and even more in T2. Factor analysis revealed that both root dry weight, positively influenced by main root diameter, root surface area, and root volume (accounting for 64.74 % of total variance), along with active constituent content played a crucial role in determined the active constituent yields, with root dry weight being the major contributor. Therefore, this study underscores the importance of optimizing irrigation strategies in the cultivation of S. baicalensis. Ensuring water supply to mitigate severe drought (40 %FC drought stress), particularly during the later growth stage, is crucial for achieving high-yield and high-quality of S. baicalensis.

中文翻译：

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不同生长阶段的干旱胁迫通过抑制 Scutellaria baicalensis Georgi 的根系形态来降低干重和活性成分产量的积累


在全球气候变化加剧的背景下，干旱胁迫极大地影响了药用植物的生长、产量和质量。本研究分析了干旱胁迫对黄琴 （Scutellaria baicalensis Georgi） （又称“黄琴”） 在关键生育阶段的影响，强调了在全球气候变化下合理灌溉策略种植的必要性。我们进行了浇水充足的 （CK）、叶片伸展阶段 （LES） 干旱胁迫 （T1） 和种子成熟阶段 （SRS） 干旱胁迫 （T2） 处理的盆栽试验。我们评估了每个阶段和收获的根形态、生理学和活性成分含量。结果显示，在干旱胁迫下，特别是在 SRS 期间，根干重和活性成分产量显著降低。与CK相比，LES和SRS期间根系干重分别显著降低了48.87 %和21.22 %，其中SRS胁迫比采收时LES胁迫降低了11.43 %。此外，黄芩苷、黄芩素、沃戈诺苷和汉黄芩素等活性成分在 T1 中也经历了显着的产量降低，在 T2 中甚至更多。因子分析显示，受主根直径、根表面积和根体积的正向影响（占总方差的 64.74 %）的根干重以及活性成分含量在决定活性成分产量方面起着至关重要的作用，其中根干重是主要贡献者。因此，本研究强调了优化灌溉策略在 S. baicalensis 栽培中的重要性。 确保供水以缓解严重干旱（40 %FC 干旱胁迫），特别是在生长后期，对于实现 S. baicalensis 的高产和高质量至关重要。