Comparison of the abilities of vegetation indices and photosynthetic parameters to detect heat stress in wheat
Comparison of the abilities of vegetation indices and photosynthetic parameters to detect heat stress in wheat
复制标题
植被指数和光合参数检测小麦热胁迫能力的比较
DOI：
10.1016/j.agrformet.2018.11.009
复制
发表时间：
2019-02-15
影响因子：
6.2
通讯作者：
Zhu, Yan
中科院分区：
文献类型：
--
作者：
Cao, Zhongsheng;Yao, Xia;Zhu, Yan
随着气候的变化，对小麦（Tritieum aestivum L.）生产以往的研究表明，光合参数可以作为胁迫条件的指标，植被指数（维斯）提供了非破坏性监测光合参数的能力。然而，目前还不清楚是否维斯可以用来检测热胁迫类似的方式作为光合参数。此外，用于指示热应力和检测应力状态的最佳维斯目前也是未知的。在本研究中，设计了四个温度水平[T1，17 ℃/27 ℃（T-min/T-max），T2（25 ℃/35 ℃），T3（29 ℃/39 ℃）和T4（33 ℃/43 ℃）]和三个处理持续时间[3天（D1），6天（D2）和9天（D3）]的热应激实验。选择叶片叶绿素含量（LCC）、净光合速率（Pn）和光系统II最大效率（Fv/Fm）3个光合参数和17个已发表的维斯指标，比较它们对高温胁迫的敏感性，并评估它们用于高温胁迫检测的可行性。结果表明，F-v/F-m是对热胁迫最为敏感的光合参数，在轻度或早期水平上具有指示热胁迫开始和结束的能力。叶绿素红边指数（CIred-edge）、归一化差值红边指数（NDRE）和光化学反射指数（PRI）与光合参数关系密切，对高温胁迫敏感。在这三种维斯中，PRI的敏感性最高。但PRI的敏感性不如F-v/F-m，且不能反映持续3 d的热胁迫的开始和结束。当热胁迫持续时间增加到7天时，PRI检测热胁迫的能力与F-v/F-m相似。因此，F-v/F-m是反映高温胁迫早期光合功能变化的最佳指标。相比之下，PRI，一种非破坏性指标，很好地指示相对后期的热胁迫，其中叶片的化学和物理特性（例如，叶绿素含量）受到影响。
With the changing of the climate, the detection of heat stress as early as possible has become increasingly important for wheat (Tritieum aestivum L.) production. Previous studies have demonstrated that photosynthetic parameters can serve as indicators of the stress conditions, and vegetation indices (VIs) provide the ability to non-destructively monitor photosynthetic parameters. However, it remains unclear whether VIs can be used to detect heat stress in a similar manner as the photosynthetic parameters. In addition, the optimal VIs for indicating heat stress and detecting the stress status are also currently unknown. In the present study, a heat stress experiment was designed with four temperature levels [T1, 17 degrees C/27 degrees C (T-min/T-max), T2 (25 degrees C/35 degrees C), T3 (29 degrees C/39 degrees C), and T4 (33 degrees C/43 degrees C)] and three treatment durations [three days (D1), six days (D2) and nine days (D3)]. Three photosynthetic parameters [leaf chlorophyll content (LCC), net photosynthesis rate (P-n), and maximum efficiency of photosystem II (F-v/F-m)] and 17 published VIs were selected to compare their sensitivity and assess their feasibility for detecting heat stress. The results showed that F-v/F-m was the most sensitive photosynthetic parameter to heat stress and had the ability to indicate the start and end of heat stress at the slight level or the early stage. The chlorophyll index-red edge (CIred-edge), normalized difference red edge index (NDRE) and photochemical reflectance index (PRI) were sensitive to heat stress owing to their close relationships with photosynthetic parameters. Among these three VIs, PRI displayed the highest sensitivity. Nevertheless, the sensitivity of PRI was less than that of F-v/F-m, and it failed to detect the beginning and end of heat stress lasting for three days. The ability of PRI to detect heat stress became similar to that of F-v/F-m when the duration of heat stress was increased to seven days. In conclusion, F-v/F-m is the optimum indicator for detecting early-stage heat stress, in which only the photosynthetic functions change. In contrast, PRI, a non-destructive indicator, works well to indicate relatively late-stage heat stress, in which the chemical and physical characteristics of leaves (e.g., chlorophyll content) are affected.