Analysis on photosynthetic rate, transpiration rates and volatile chemical constituents from leaves of various Houttuynia Chemotypes at varied growth stages

Chino. 研究两种化学型鱼腥草不同生育期叶片净光合速率和蒸腾速率以及挥发油化学成分的差异。用便携式光合仪测定自然条件下两种化学型鱼腥草苗期和花期叶片的净光合速率(Pn)和蒸腾速率(Tr)日变化。用水蒸气蒸馏法分别提取挥发油，并用GC-MS法对各化合物进行鉴定，峰面积归一法计算各成分相对含量。LSD多重比较法进行差异显著性检验。两种化学型鱼腥草Pn日变化苗期均为典型的单峰曲线，而花期呈双峰形；Tr日变化则两个时期均为单峰曲线；且苗期Pn和Tr值均极显著低于花期。两种化学型鱼腥草叶片挥发油所含组分数目苗期普遍比花期多，而共有成分和主要成分总量分别低于花期。M型鱼腥草叶片挥发油所含化学成分种类较D型多，而其挥发油化学成分中共有成分和主要成分总量却较D型低，且该化学型不同材料间在某些主要成分含量上存在极显著差异。不同化学型鱼腥草在不同生育期的净光合速率和蒸腾速率以及挥发油化学成分上均存在一定程度的差异。而峨眉蕺菜与蕺菜之间，无论在净光合速率和蒸腾速率还是挥发油化学成分方面均无显著差异。

Inglés. The study compared the net photosynthetic rate (Pn), transpiration rate (Tr) and volatile chemical constituents of two different Houttuynia leaves chemotypes at different growth stages. The diurnal variation of Pn and Tr were determined with CIRAS-1 under natural conditions. Volatile oils were obtained with steam distillation and the chemical constituents were separated and identified by GC-MS. The relative content of each constituent was determined by area normalization. The curve of diurnal variation of Pn tended to be a typical single peak at the seedling stage and double peak type at the flowering stage. Tr diurnal variation curves at both stages were single peak types. Both Pn and Tr values at seedling stage were much higher than that at the flowering stage in all the tested materials. Meanwhile, the numbers of volatile chemical constituents were also more plentiful at the seedling stages than at the flowering stage. The total contents of common and major volatile chemical constituent were much lower at the seedling stage than at the flowering stage. The numbers of the volatile chemical Myrcene (M) chemotype were much more plentiful than Decanal(D) chemotypes at both stages. While the total contents of common and major volatile chemical constituent of M chemotype were much lower than that of D chemotype. Furthermore, there were extremely significant differences among the contents of some major chemical constituents in different materials of M chemotypes at both stages. Houttuynia chemotypes at various growth stages showed certain differences on Pn, Tr andvolatile chemical constituents. And there were no significant differences between Houttuynia emeiensis Z.Y. Zhu et S.L. Zhang and Houttuynia cordata Thunb. or Pn, Tr and volatile chemical constituents of their leaves3.