目的 研究不同温度和聚乙二醇（PEG）模拟干旱胁迫对大黄种子萌发的影响，探讨大黄种子萌发的最适温度和对干旱胁迫的耐性。方法 用6个温度（10、15、20、25、30、35 ℃）和6个聚乙二醇（PEG-6000，以下简称PEG）浓度（0、5%、10%、15%、20%、25%）模拟温度胁迫与干旱胁迫对大黄种子进行处理，置人工培养箱培育，借助SPSS 24.0单因素方差分析法对其发芽势、发芽率、胚根、胚轴和子叶等指标统计分析。结果 温度与干旱胁迫对3种大黄种子萌发及幼苗生长有显著影响（P＜0.05）；同一温度下，3种大黄的种子萌发指标随PEG浓度的升高而降低，掌叶大黄和唐古特大黄幼苗各指标亦是随PEG浓度的升高而降低，而药用大黄幼苗各指标随着PEG浓度的升高先增加后减小，在低浓度PEG（5%）达到最大，25%PEG重度干旱时严重抑制掌叶大黄和唐古特大黄萌发（P＜0.05），完全抑制药用大黄萌发；20 ℃或25 ℃下，各PEG浓度处理的3种大黄种子萌发及幼苗生长指标均达到最大值；在低于20 ℃或者高于25 ℃时，各PEG浓度下的指标呈下降趋势，35 ℃高温下种子萌发和幼苗生长指标随着PEG浓度的升高呈直线下降。结论 掌叶大黄和唐古特大黄种子在各处理下所有指标均高于药用大黄，萌发的速度和整齐度较好，种子的活力高，表现出较强的抗旱性，轻度干旱环境有利于药用大黄幼苗生长，为大黄种质资源评价及规范种植研究与应用提供了理论依据。

Objective To study the effect of different temperature and PEG-6000 simulated drought stress on seed germination of Rhubarb, exploring the optimum temperature and tolerance of seed germination of rhubarb under drought stress.Method To use six temperatures (10, 15, 20, 25 and 30, 35 ^oC) and six PEG concentrations (0, 5%, 10%, 15%, 20%, 25%) to simulate the temperature stress and drought stress to deal with rhubarb seeds, artificial culture box, with the help of SPSS 24.0 single factor variance analysis on the germination potential, germination rate, germination index, radical length, hycopotyl length, cotyledon length index statistics and analysis. Results Drought and temperature had significant effects (P＜0.05) on the seed germination and seedling growth of these three rhubarbs. Under the same temperature condition, seed germination indexes deceased with the increasement of PEG concentrations for these species. For R. palmatum and R. tanguticum, seedling growth indexes decreased as PEG concentrations increased. R. officinaleseedling growth indexes showed increased then decreased and reached peak at 5% PEG. 25% PEG severely repressed R. palmatum and R. tanguticum germination, and completely inhibited R. officinale germination. At 20 ^oC or 25 ^oC, seed germination and seedling growth indexes of the three rhubarbs all reached maximum under various PEG concentrations. At temperatures below 20 ^oC or over 25 ^oC, seed germination and seedling growth indexes displayed decreasing trend, while showing decreased dramatically at 35 ^oC high temperature. Conclusion Over all, under all experimental conditions, indexes of R. palmatum and R. tangutum seeds showed better germination speed and uniformity, higher seed vigor, and stronger drought resistance than those of R. officinalis. Mild drought might be good for seedling growth ofR. officinalis. This study provided a theoretical basis for the germplasm assessment, standard cultivation research and applications of rhubarb.

R286.2

国家自然科学基金资助项目（81973430）；国家自然科学基金资助项目（82104334）；陕西省重点产业创新链项目（2021ZDLSF04-01）；陕西中医药大学新进博士科研启动经费（104080001）；陕西中医药大学学科创新团队项目（2019-QN01）；省部共建特色秦药资源研究开发国家重点实验室（培育）开放课题（QY202101）