MINTOTA research group, Departament de Química Analítica, Facultat de Química, Universitat de València, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain.
MINTOTA research group, Departament de Química Analítica, Facultat de Química, Universitat de València, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain.
Sci Total Environ. 2017 Dec 31;609:370-376. doi: 10.1016/j.scitotenv.2017.07.140. Epub 2017 Jul 25.
Chlorophyll is a key biochemical component that is responsible for photosynthesis and is an indicator of plant health. The effect of stressors can be determined by measuring the amount of chlorophyll a, which is the most abundant chlorophyll, in vegetation in general. Nowadays, invasive methods and vegetation indices are used for establishing chlorophyll amount or an approximation to this value, respectively. This paper demonstrates that H-point curve isolation method (HPCIM) is useful for isolating the signal of chlorophyll a from non-invasive diffuse reflectance measurements of leaves. Spinach plants have been chosen as an example. For applying the HPCIM only the registers of both, a standard and the sample are needed. The results obtained by HPCIM and the invasive method were statistically similar for spinach leaves: 144±6mg/m (n=5) and 155±40mg/m (n=5), respectively. However, more precise values were achieved with the HPCIM, which also involved minimal experimental effort. The HPCIM method was applied to spinach plants stressed by the action of several pesticides and water scarcity, showing a decrease of chlorophyll a content with time, which is related with a loss of health. The results obtained were compared with those achieved by two different reflectance vegetation indices (Macc01 and NDVI). Although NDVI and HPCIM gave similar footprints for the plants tested, vegetation indices fail in the estimation of real content of the chlorophyll a. The HPCIM could contribute to improve the knowledge of the chlorophyll a content of vegetation like health indicator, by applying it to a much employed non-invasive technique such as diffuse reflectance, which can be used in place or in remote sensing mode.
叶绿素是一种关键的生化成分，负责光合作用，是植物健康的指标。可以通过测量植被中最丰富的叶绿素 a 的含量来确定胁迫因子的影响。如今，分别采用侵入性方法和植被指数来建立叶绿素的含量或其近似值。本文证明 H 点曲线分离法（HPCIM）可用于从叶片的非侵入性漫反射测量中分离叶绿素 a 的信号。以菠菜植物为例。应用 HPCIM 仅需标准和样品的寄存器。HPCIM 和侵入性方法获得的菠菜叶片结果在统计学上相似：144±6mg/m（n=5）和 155±40mg/m（n=5）。然而，HPCIM 获得的结果更精确，而且所需的实验工作量也更小。该方法应用于受到几种杀虫剂和缺水胁迫的菠菜植物，随着时间的推移观察到叶绿素 a 含量的减少，这与植物健康状况的下降有关。将获得的结果与两种不同的反射植被指数（Macc01 和 NDVI）的结果进行比较。尽管 NDVI 和 HPCIM 对测试植物的足迹相似，但植被指数在叶绿素 a 的实际含量估计方面存在不足。HPCIM 可以通过将其应用于广泛使用的非侵入性技术（如漫反射）来提高对植被中叶绿素 a 含量的了解，该技术可用于原位或遥感模式。
