乌天麻（Gastrodia elata f. glauca）是兰科天麻属植物天麻的一个变型，作为我国传统名贵中药材，天麻具有息风止痉、镇静安神、益智、提高免疫等诸多功效。2023年，国家卫生健康委员会和国家市场监督管理总局联合发布公告，将天麻纳入《按照传统既是食品又是中药材的物质目录》，明确了其药食两用属性。目前，主流的天麻人工栽培变型包括红天麻（G. elata f. elata）、乌天麻（G. elata f. glauca）和少量绿天麻（G. elata f. viridis）。其中，乌天麻具备麻形状好、折干率高、口味佳等优点，价格可达红、绿天麻的五倍左右。然而，针对天麻不同变型，缺乏作为食药用物质的系统性品质研究，同时其分子特征研究也有待深入。本研究以乌天麻为研究材料，对照红、绿天麻，从农艺性状、营养物质、化学成分及药理活性、分子特征多个维度探究乌天麻独特的品质特征。

首先，通过MaxEnt模型进行地理分布分析，得到影响天麻分布的气候变量的主要因子为温度、降水、海拔和坡度。对天麻适生区分布进行预测，高适生区主要集中我国西南地区，北纬24.5° - 34.5°，东经102.5° - 111.5°之间区域，分布面积为25.73×10⁴ km²。野生乌天麻与红、绿天麻的分布有差异，乌天麻主要沿乌蒙山脉和巫山山脉分布，大部分在中适生区，分布海拔约1975 m，而红、绿天麻分布范围较广，分布在约1376 m的中低海拔区域。其次，对不同天麻块茎在块茎宽、宽周长、折干率等8个方面的性状进行分析，乌天麻综合品质评分为0.6157，而绿天麻和红天麻为0.5386和0.4344，乌天麻的综合品质评分优于红、绿天麻。再次，对于天麻花色差异进行色素分析，发现乌天麻（68.05 ± 2.42 μg/g）和绿天麻（64.57 ± 3.35 μg/g）的叶绿素含量显著高于红天麻（28.56 ± 0.29 μg/g）；类胡萝卜素的含量为表现为乌天麻（20.75 ± 0.92 μg/g）显著高于红天麻（13.81 ± 0.39 μg/g）和绿天麻（6.47 ± 0.90 μg/g）；利用UPLC-MS/MS技术对天麻花的黄酮类成分进行检测，发现三种变型的黄酮组成相似，但含量有差异；其中木犀草素、Agrandol等五种相对含量较高的黄酮，均表现为绿天麻＞乌天麻＞红天麻。

对不同变型天麻叶绿体基因组特征进行分析，发现乌天麻的基因组（35371 ± 66 bp）显著大于红天麻（35158 ± 61 bp）和绿天麻（35134 ± 30 bp）。其中，乌天麻的串联重复数量最低，仅有15个；而红天麻和绿天麻的叶绿体基因组中则额外具有2-3个回文重复序列。天麻属基因组平均核苷酸多态性Pi值为0.081908，其中核苷酸多态性最高的片段是ycf2基因，根据该片段设计了分子标记，可以根据一段插入序列和一个SNP位点准确鉴别乌天麻。系统发育树显示accD、rpl20、rps3、

rps7、rps8、rps18、ycf1、ycf2共8个基因可以将乌天麻分支为单独的亚类群，而红天麻和绿天麻汇聚为一个亚类群，乌天麻与红、绿天麻可以进行区分。

基于LC-ESI-MS/MS非靶向代谢组全面解析了三种变型天麻的次级代谢产物差异。结果共注释到102种芳香族化合物、2种呋喃、4种碳水化合物、11种有机酸及其酯、11种含氮化合物、8种含硫化合物，3种其他类代谢产物。差异代谢物主要富集在苯丙烷类代谢通路，乌天麻的巴利森苷种类及含量比红天麻和绿天麻更为丰富。对天麻素、对羟基苯甲醇以及四种巴利森苷类成分进行定量分析，发现对羟基苯甲醇在乌天麻中含量（5.2 ± 0.11 mg/g）高于红天麻（4.86 ± 0.35 mg/g）和绿天麻（2.9 ± 0.3 mg/g），巴利森苷E在乌天麻中含量（6.92 ± 0.57 mg/g）也高于红天麻（3.02 ± 0.17 mg/g）和绿天麻（5.11 ± 0.06 mg/g）。同时，研究发现经蒸制炮制后的天麻成分含量有显著变化，巴利森苷A含量平均提高了6.84倍，巴利森苷B含量平均提高了8.11倍，巴利森苷C含量平均提高了27.86倍，巴利森苷E平均提高了2.95倍，而对羟基苯甲醇则平均降低至0.55倍。

营养成分分析发现，乌天麻淀粉含量（74.63 ± 2.9 g/100 g）显著高于红天麻（65.63 ± 1.8 g/100 g）和绿天麻（71.23 ± 5.29 g/100 g）；在蛋白质方面乌天麻（6.8 ± 0.2 g/100 g）同样显著高于红天麻（5.97 ± 0.14 g/100 g）和绿天麻（6.32 ± 0.04 g/100 g）。乌天麻的纤维素含量（50.56 ± 0.78 g/kg）显著高于红天麻（32.95 ± 1.24 g/kg）和绿天麻（46.2 ± 1.13 g/kg），而半纤维素含量乌天麻（32.52 ± 0.60 g/kg）显著低于红天麻（47.91 ± 0.85 g/kg）和绿天麻（47.03 ± 0.88 g/kg）。利用电子舌对风味进行评价，发现乌天麻的苦味值最低（3.60 ± 0.57），显著低于红天麻（5.20 ± 0.39）和绿天麻（5.41 ± 0.60）；而甜味值乌天麻（16.15 ± 0.31）显著高于红天麻（14.41 ± 0.80）和绿天麻（14.85 ± 1.12）。基于代谢组分析，天麻中的苦味化合物可能为酚酸类化合物、苦味氨基酸及腺苷；对其进行定量分析，天麻中含量最高的酚酸（及前体）成分为对羟基苯甲醛（8.87 - 11.18 μg/g）和阿魏酸（1.77 - 7.33 μg/g）；同时，琥珀酸（19.88 - 49.35 μg/g）也被报道呈现苦味。研究发现，琥珀酸和阿魏酸的含量表现为红天麻＞绿天麻＞乌天麻，同时红天麻和绿天麻中的苦味氨基酸总量显著高于乌天麻。相关性分析显示酚酸类化合物、苦味氨基酸及腺苷三类苦味物质影响着天麻的食品风味，乌天麻低苦味的食用品质与其苦味化合物含量低有关。此外，乌天麻口感粉面，可能与其淀粉的粒径小、直链淀粉比例高有关。

天麻水提物中主要的化学成分为多糖（66.89% - 75.54%）和对羟基苯甲醇（1.14% - 2.60%），在2 - 6 mg/mL浓度范围，乌天麻水提物的体外抗氧化能力显著高于红天麻和绿天麻水提物。天麻水提物对过氧化氢损伤的PC12细胞具有保护作用，在低剂量（10 μg/mL）下乌天麻组处理后的细胞存活率（79.66 ± 4.42%）显著高于红天麻（61.3 ± 3.76%）和绿天麻（67.07 ± 3.22%）、而中、高剂量组（20、50 μg/mL）细胞存活率无显著差异。天麻水提物可以不同程度地降低细胞内NO、IL-6、TNF-α炎症因子分泌水平，提高CAT、SOD、GSH-PX抗氧化酶指标。

本研究对乌、红、绿三个不同变型天麻进行了系统性特征比较，探究乌天麻独特的品质特征，为天麻混伪品鉴别、优质种质资源保护及质量评价提供参考。为推动天麻功能性食品、保健品开发提供基础。

Gastrodia elata f. glauca is an infraspecific form of Gastrodia elata (Orchidaceae), a renowned traditional Chinese medicinal herb with multiple pharmacological effects, including calming convulsions, sedative and neuroprotective properties, cognitive enhancement, and immune regulation. In 2023, the National Health Commission and the State Administration for Market Regulation jointly announced the inclusion of Gastrodia elata in the "Substance Catalog of Dual Use as Food and Traditional Chinese Medicine," officially recognizing its medicine and food attributes. Currently, the primary cultivated forms are G. elata f. glauca (W), G. elata f. elata (H), and G. elata f. viridis (L). Due to its superior tuber morphology, high drying rate, and palatability, W commands a market price approximately five times higher than that of H and L. However, research on infraspecific forms of Gastrodia elata remains limited, with a lack of systematic studies on the medicinal-edible quality of W, H, and L, as well as insufficient exploration of their molecular genetic characteristics. This study investigates the unique quality traits of W using H and L as controls, focusing on agronomic traits, nutrient content, chemical composition, pharmacological activity, and molecular features. Key findings are as follows:

Firstly, MaxEnt modeling identified temperature, precipitation, altitude, and slope as the primary climatic factors influencing the modern geographical distribution of Gastrodia elata. The predicted highly suitable habitats are concentrated in southwestern China (24.5°N - 34.5°N latitude and 102.5°E - 111.5°E longitude), covering an area of 257,300 km² (2.68% of China’s total land area). W is is primarily distributed along the Wumeng Mountains and Wushan Mountains, with most populations located in moderately suitable habitats, while H and L have a broader distribution range. Secondly, agronomic analysis of tubers (e.g., tuber width, perimeter, and drying rate) revealed a comprehensive quality score ranking: W (0.6157) > L (0.5386) > H (0.4344). Moreover, pigment analysis showed significantly higher chlorophyll content in W (68.05 ± 2.42 μg/g) and L (64.57 ± 3.35 μg/g) compared to H (28.56 ± 0.29 μg/g). Carotenoid content followed the order W (20.75 ± 0.92 μg/g) > H (13.81 ± 0.39 μg/g) > L (6.47 ± 0.90 μg/g), with significant differences. UPLC-MS/MS analysis of flavonoids in flowers indicated identical compositional profiles across the three forms but varying concentrations. The five most abundant flavonoids exhibited the trend L > W > H, with compounds such as luteolin and agrandol identified.

2. Based on chloroplast genome analysis. The chloroplast genome size of W (35,371 ± 66 bp) was significantly larger than those of H (35,158 ± 61 bp) and L (35,134 ± 30 bp). W exhibited the lowest number of tandem repeats (15), while H and L contained 2-3 additional palindromic repeats. The average nucleotide diversity (Pi value) of the W chloroplast genome was 0.081908, with the highest polymorphism observed in the ycf2 gene. A molecular marker designed based on this region (featuring an insertion sequence and a SNP locus) enables accurate identification of W. Phylogenetic analysis revealed that eight genes (accD, rpl20, rps3, rps7, rps8, rps18, ycf1, and ycf2) distinguish W as a distinct subgroup, while H and L cluster together, indicating closer genetic relatedness between the latter two.

3. A comprehensive analysis of secondary metabolites identified 102 aromatic compounds, 2 furans, 4 carbohydrates, 11 organic acids/esters, 11 nitrogen-containing compounds, 8 sulfur-containing compounds, and 3 other metabolites across the three varieties. Differential metabolites were primarily enriched in the phenylpropanoid biosynthesis pathway. W exhibited higher diversity and abundance of Parishins compared to H and L. Quantitative analysis showed: p-Hydroxybenzyl alcohol: W (5.20 ± 0.11 mg/g) > H (4.86 ± 0.35 mg/g) > L (2.90 ± 0.30 mg/g). Parishin E: W (6.92 ± 0.57 mg/g) > L (5.11 ± 0.06 mg/g) > H (3.22 ± 0.17 mg/g). Steaming processing significantly altered metabolite content: Parishin A increased by 6.84-fold, Parishin B by 8.11-fold, Parishin C by 27.86-fold, and Parishin E by 2.95-fold, while p-hydroxybenzyl alcohol decreased to 0.55-fold of its original level.

4. Nutritional analysis reveals that starch content: W (74.63 ± 2.90 g/100 g) > L (71.23 ± 5.29 g/100 g) > H (65.63 ± 1.80 g/100 g). Protein content: W (6.80 ± 0.20 g/100 g) > L (6.32 ± 0.04 g/100 g) > H (5.97 ± 0.14 g/100 g). W exhibited significantly elevated cellulose levels (50.56 ± 0.78 g/kg) compared to H(32.95 ± 1.24 g/kg) and L(46.2 ± 1.13 g/kg), whereas its hemicellulose content (32.52 ± 0.60 g/kg) was markedly reduced relative to both H(47.91 ± 0.85 g/kg) and L(47.03 ± 0.88 g/kg). Electronic tongue analysis revealed: Bitterness: W (3.60 ± 0.57) < L (5.41 ± 0.60) < H (5.20 ± 0.39). Sweetness: W (16.15 ± 0.31) > L (14.85 ± 1.12) > H (14.41 ± 0.80). The sweeter taste of W and bitter preference of H/L may stem from lower phenolic acids, bitter amino acids, and adenosine based on metabolomics analysis. Phenolic acids and its precursors: p-hydroxybenzaldehyde (8.87 - 11.18 μg/g), ferulic acid (1.77 - 7.33 μg/g), and succinic acid (19.88 - 49.35 μg/g),with levels ranking H > L > W. Bitter amino acids and adenosine: Total content was significantly higher in H and L, which influence its flavor. Moreover, Its loury mouthfeel is likely linked to smaller starch granules and higher amylose content.

5. The primary components of Gastrodia elata aqueous extracts were polysaccharides (66.89% - 75.54%) and p-hydroxybenzyl alcohol (1.14% - 2.60%). At 2 - 6 mg/mL, W extracts demonstrated significantly higher in vitro antioxidant capacity than H and L. Additionally: Cytoprotective effects: At 10 μg/mL, W-treated H₂O₂-damaged PC12 cells showed higher viability (79.66 ± 4.42%) compared to H (61.30 ± 3.76%) and L (67.07 ± 3.22%). No significant differences were observed at higher doses (20, 50 μg/mL). Anti-inflammatory and antioxidant effects: Extracts reduced intracellular NO, IL-6, and TNF-α levels and elevated CAT, SOD, and GSH-Px activity.

This study conducted a systematic comparative analysis of three G. elata varieties to investigate the unique quality characteristics of G. elata f. glauca. The research provides scientific references for identifying adulterants, conserving superior germplasm resources, and establishing quality evaluation standards. The findings aim to facilitate the development of functional foods and health products derived from G. elata.