黄芩（Scutellaria baicalensis Georgi）是我国常见大宗中药材。经调研黄芩资源质量不稳定与野生资源的破坏是黄芩资源的两大问题，为保证黄芩资源的保护与可持续利用，应加强对黄芩质量形成机理研究。水热条件是影响中药资源分布格局与质量形成的重要条件。本研究在生境、种群、个体及分子等水平上研究水分对黄芩质量形成的影响。其主要结果如下：1、对不同生境条件下的黄芩进行形态及化学成分含量分析。研究结果表明干旱指数与汉黄芩苷含量以及多个组分关系存在着线性的正相关，表明水分条件是影响着黄芩资源质量形成的主要生态因子。不同生境条件下，黄芩形态及化学成分含量差异显著，草甸生境下黄芩植株矮壮，具有较高的黄芩苷、汉黄芩苷含量；而山地生境下黄芩植株蔓长，黄芩苷、汉黄芩苷含量相对较低；不同生境条件下黄芩有效成分的差异亦有水分作用的结果。2、观察不同温度下对水分对黄芩种子萌发的影响。结果表明：黄芩种子是广适型的药用植物种子，在10-30℃的变温条件下均能良好萌发，15-25℃是其最适萌发温度。水分是影响黄芩种子萌发的重要因素，适温条件下充分水分条件有利于种子萌发，干旱处理抑制黄芩种子萌发；低温或高温条件下，水分对黄芩种子的浸泡造成黄芩种子活力的丧失；而干旱条件可使黄芩种子在此环境中保持良好的萌发潜力。3、通过盆栽试验研究水分对当年生黄芩初级生长的影响。结果表明：轻度干旱显著地促进了黄芩初级生长，充分水分条件和重度干旱严重抑制了黄芩的初级生长。在不同生长时期，水分对黄芩初级生长的作用有所不同，9月份是黄芩地上部分生物量由积累转为转移的时期，轻度干旱在时间上可以提早促进地上部分生物量的转移，8、9月份是黄芩地下部分生长积累的主要时期，轻度干旱在黄芩根部生长期具有促进根部生长与生物量积累的作用。8、9月份是黄芩株高的形成时期，轻度干旱促进了黄芩株高的形成；8、9月份是黄芩全株生物量积累的主要时期，进入10月份，黄芩生物量开始转移，轻度干旱和重度干旱在时间上提早了对其生物量的转移，充分水分条件下，黄芩生物量积累受阻。黄芩生物量具有不断向根部转移的趋势，其最大的趋势出现在10月份。4、通过HPLC测定不同水分处理当年生黄芩化学成分含量变化。结果表明，轻度干旱或中度干旱条件下黄芩有效成分含量较高，而充分水分和重度干旱条件下相对较低。水分对不同有效成分的效应不同，8月份是黄芩苷合成与积累的主要时期，中度干旱胁迫提高了黄芩苷含量。轻度干旱条件下，黄芩素含量水平相对较低，而充分水分条件或重度干旱条件下相对较高。适当的水分条件也利于汉黄芩苷的累积，在汉黄芩苷合成时期，轻度干旱和充分水分条件促进了汉黄芩苷的合成与累积，而重度或中度干旱使汉黄芩苷分解提前；轻度干旱胁迫下汉黄芩素水平相对较低，而重度干旱或中度干旱条件下相对较高。5、采用荧光PCR技术对不同水分处理下黄芩有效成分生物合成途径关键基因（CHS、UBGAT、SGUS）相对表达量进行差异分析。结果表明，黄芩生物合成关键基因表达差异是黄芩有效成分积累差异的主要原因。轻度干旱或中度干旱条件下，CHS表达量相对较高，8月份是CHS表达量相对较高的时期，其后表达水平逐渐降低；UBGAT相对表达水平受重度干旱诱导，并随着土壤含水量的增加而降低，GUS与UBGAT具有显著地正相关，在重度干旱下表达量最高。可见，水分对黄芩质量形成存在着逆境积累的机制。水分影响黄芩初级生长的根部积累，根部积累影响CHS表达，CHS表达差异造成有效成分差异，最终影响黄芩质量的形成，则是黄芩质量形成可能的“环境-生物-化学”机制。

Scutellaria baicalensis Georgi. is one of common Chinese traditional medical. In this study, serial experiments were carried in the levels of system ecology, habitats, population, single plant and molecular, which based on Quality form of Scutellaria baicalensis. The main results were following:1. Analysis of morphological and bioactive components variations were determined two ecotypes from different habitats. Results showed that aridity index correlated to wogonoside content and several bioactive components relationships in positive linearity. Significant morphological variation showed between S. baicalensis Georgi from different habitats. In the habitats of hilly, S. baicalensis Georgi sprawled and showed higher plant height, while lower plant height and stocky architecture obtained in type of meadow habitats. Higher baicalin and wogonoside content were obtained in S. baicalensis Georgi from meadow habitats, while lower baicalin and wogonoside in hilly habitats. Clustering analysis results also showed that significant variation between different population of S. baicalensis Georgi form different habitats based on the relationships of bioactive components. We proposed that different water condition of different habitats may relate to quality form of S. baicalensis Georgi, accordingly, it’s necessary to conduct such research which determined the exact effect of different water condition on the quality form of S. baicalensis Georgi.2. The germination behavior of Scutellaria baicalensis Georgi seeds on water stress in different thermoperiods was observed. Results showed that seeds of S. baicalensis has a wide adaptability ability in seed germination temperature, it can germinate as thermoperiods of 10-30℃, and the optimal thermoperiods of this seed was 15-25℃. Water condition was an important factor which affect seed germination of S. baicalensis seeds, in the optimal thermoperiods, sufficient water can favor seed germination, drought stress inhibit seed germination; and in the higher or lower thermoperiods, sufficient water supply may attribute to seed vigor lose, while drought condition can preserve seed vigor. In conclusion, water was the functional factor in formative mechanism of S. baicalensis quality.3.A pot culture research was conducted to determine the effect of different water condition on Scutellaria baicalensis Georgi growth and biomass accumulation in the sowing year. Results showed that moderate drought stress promoted primary growth of S. baicalensis, that showed higher height, biomass accumulation. Sufficient water and severe drought stress inhibited primary growth of S. baicalensis. In the time scale for different orange of S. baicalensis Georgi, shoot biomass begin to transfer from September, mild drought stress advanced shoot biomass transfer for S. baicalensis, while moderate and severe drought stress delayed shoot biomass transfer, while in the sufficient water condition, shoot growth was inhibited strongly. Root biomass accumulated mainly in August and September, and then transferred in the beginning of October; mild drought stress can promote root biomass accumulation, while moderate drought stress can reduce biomass transfer. In sufficient water and severe drought condition, root primary growth was inhibited strongly. The height of S. baicalensis Georgi formed in August and September, mild drought stress promoted height, the plant biomass accumulated mainly in August and September, then transferred in the beginning of October, and mild and severe drought stress advanced the transfer trend in the time scale. In the sufficient water condition, the plant biomass was suffocated in biomass accumulation. The plant biomass has a trend of accumulation biomass into root from beginning to end, and this trend showed distinctly in October. In conclusion, the quality of S. baicalensis formed in September and October, in the period of root biomass accumulation, mild drought stress would be conducted in order to increase root biomass accumulation, while in the period of root biomass transfer, moderate drought stress would be conducted in order to reduce biomass transfer.4. The main bioactive components of different water treatments for Scutellaria baicalensis Georgi were measured by HPLC, the components relationships was established by biosynthetic pathway. Results showed that moderate water condition (moderate drought stress and mild drought stress) promoted second metabolites accumulation, and sufficient water and severe drought stress inhibited second metabolites accumulation. In the time scale for different components of S. baicalensis Georgi, baicalin was synthesized mainly in August, mild drought stress promoted baicalin accumulation, baicalin began to decompose in the beginning of September, and sufficient water inhibited baicalin decomposition, severe drought stress promoted. Low level of baicalein showed in the moderate drought stress while higher baicalein content was obtained in sufficient water or severe drought condition. Moderate water condition promoted wogonoside accmulaiton, moderate drought and sufficient water condition promoted wogonoside biosynthesis and accumulation; while mild drought and severe drought stress advanced the decompose of wogonoside. Low level of wogonin showed in the moderate drought stress while higher wogonin content was obtained in mild and severe drought condition. The relationship between wogonin (wogonosied) and baicalein (baicalin) was found in this research, different water conditions modulate the biosynthesis way and final accumulation.In conclusion, the quality of S. baicalensis Georgi formed in August and September, in the period of components biosynthesis, moderate drought stress would be conducted in order to promoted bioactive components accumulation, while in the period of components decomposition, mild drought stress would be conducted in order to reduce bioactive components.5. Various analysis of the pivotal genes relative transcript levels in biosynthesis pathway of Scutellaria baicalensis Georgi under different water treatments by real-time PCR are conducted.The relative analysis of primary growth, pivotal genes real-time expression and secondary metabolites accumulation was determined.Results showed the diversity of pivotal genes expression was the primary reason which attribute to bioactive components accumulation under different water conditions. Real-time PCR results showed that CHS expressed higher levels under the moderate drought and mild drought stress, the CHS was the fastigium in the August and then gradually reduce in the time scale. The expression levels of UBGAT, was induced by severe drought stress, and decreased as the increase of the soil water content. GUS expression remarkably positively correlated to UBGAT, the higher expression levels was obtained on the severe drought stress. In collusion, water affected root biomass accumulation in the primary growth, and the root biomass accumulation conducted the diversity of expression levels of CHS, while such significant transcript levels related to the bioactive components accumulation and form the quality of S. baicalensis Georgi.