Hyperspectral images of Marchantia polymorpha under nutrient stress

Plant material and growth condition – M. polymorpha gemma (Accession: Tak-1) was spread on ½ x B-5 medium (PhytoTechnology Laboratories) with 1% agar and grown at 22oC under continuous light (50–60 µmol m−2 s−1). Seven-day old gemmalings were then transferred to full-strength Yamagami (cntl) medium 12 or the same medium with the reduced concentration of 0 or 3 mM potassium nitrate and 0 or 2mM sodium nitrate (0xN or 0.05xN), 0 or 1 mM potassium phosphate (0xP or 0.05xP) , 0.1 or 0.2 mM calcium chloride (0.05xCa or 0.1xCa), 0 or 0.43 µM iron sulfate (0xFe or 0.05xFe) and 0 mM magnesium sulfate (0xMg). The gemmalings were grown at 22oC under a 24-hr continuous light during nutrient deficiency treatment. RGB and hyperspectral images were captured on the 14th day of treatment. Full strength Yamagami nutrient medium contained 2 mM magnesium sulfate, 2 mM potassium dihydrogen phosphate, 6 mM potassium nitrate, 1 mM ammonium chloride, 2 mM calcium chloride, 4 mM sodium nitrate, 8.6 µM iron (II) sulfate, 10.3 µM manganese (II) sulfate, 30 µM boric acid, 1 µM zinc sulfate, 1 µM cupric sulfate, 130 nM cobalt sulphate, 24 nM sodium molybdate. Hyperspectral imaging - Hyperspectral images of M. polymorpha plants were captured using the Specim IQ camera (SPECIM) with halogen lamps as the light source. The hyperspectral image contains 512 x 512 pixels (x, y) and 204 spectral bands (λ) from 400 to 1000 nm with a spectral resolution of 7 nm. The white balance was set according to the manufacturer protocol with the interrogation time 35 s. The interrogation time for the samples was set to 40 s and the working distance was set to 23 cm.

植物材料与培养条件——登录号为Tak-1的多形地钱（Marchantia polymorpha，缩写M. polymorpha）芽胞被接种于含1%琼脂的1/2强度B-5培养基（PhytoTechnology Laboratories品牌），于22℃、持续光照（光照强度50–60 µmol·m⁻²·s⁻¹）下培养。培养7天后的芽胞体被转接至全强度Yamagami（对照，cntl）培养基，或该培养基的养分减量化配方：分别调整硝酸钾浓度为0或3 mM、硝酸钠浓度为0或2 mM（对应0xN或0.05xN）；磷酸钾浓度为0或1 mM（对应0xP或0.05xP）；氯化钙浓度为0.1或0.2 mM（对应0.05xCa或0.1xCa）；硫酸铁浓度为0或0.43 µM（对应0xFe或0.05xFe）；硫酸镁浓度为0 mM（对应0xMg）。养分缺失处理期间，所有芽胞体均于22℃、24小时持续光照条件下培养。于处理第14天采集RGB图像与高光谱图像。

全强度Yamagami营养培养基的成分为：2 mM硫酸镁、2 mM磷酸二氢钾、6 mM硝酸钾、1 mM氯化铵、2 mM氯化钙、4 mM硝酸钠、8.6 µM硫酸亚铁(II)、10.3 µM硫酸锰(II)、30 µM硼酸、1 µM硫酸锌、1 µM硫酸铜(II)、130 nM硫酸钴、24 nM钼酸钠。

高光谱成像：使用Specim IQ相机（SPECIM品牌），以卤钨灯作为光源，采集多形地钱植株的高光谱图像。该高光谱图像分辨率为512×512像素（x、y方向），包含400~1000 nm波段范围内的204个光谱通道，光谱分辨率为7 nm。白平衡设置遵循厂商操作手册，白板校正的积分时间为35 s，样本采集的积分时间为40 s，工作距离设置为23 cm。