Natural & Medical Sciences Research Center, University of Nizwa, Nizwa, Oman.
Department of Biological Sciences & Chemistry, University of Nizwa, Nizwa, Oman.
PLoS One. 2018 Dec 19;13(12):e0207910. doi: 10.1371/journal.pone.0207910. eCollection 2018.
Boswellia sacra, an endemic tree to Oman, is exposed to man-made incisions for commercial level frankincense production, whereas unsustainable harvesting may lead to population decline. In this case, assessment of endogenous phytohormones (gibberellic acid (GA), indole-acetic acid (IAA), salicylic acid (SA) and kinetin) can help to understand population health and growth dynamics. Hence, it was aimed to devise a robust method using Near-Infrared spectroscopy (NIRS) coupled with multivariate methods for phytohormone analysis of thirteen different populations of B. sacra. NIRS data was recorded in absorption mode (10000-4000 cm-1) to build partial least squares regression model (calibration set 70%). Model was externally cross validated (30%) as a test set to check their prediction ability before the application to quantify the unknown amount of phytohormones in thirteen different populations of B. sacra. The results showed that phytohormonal contents varied significantly, showing a trend of SA>GA/IAA>kinetin across different populations. SA and GA contents were significantly higher in Pop13 (Hasik), followed by Pop2 (Dowkah)-an extreme end of B. sacra tree cover in Dhofar region. A similar trend in the concentration of phytohormones was found when the samples from 13 populations were subjected to advance liquid chromatography mass spectrophotometer and gas chromatograph with selected ion monitor analysis. The current analysis provides alternative tool to assess plant health, which could be important to in situ propagation of tree population as well as monitoring tree population growth dynamics.
乳香树是阿曼特有的树种，为了商业规模的乳香生产，人为地在其树干上切割，而这种不可持续的采集方式可能导致其数量减少。在这种情况下，评估内源性植物激素（赤霉素（GA）、吲哚乙酸（IAA）、水杨酸（SA）和激动素）可以帮助了解种群的健康和生长动态。因此，本研究旨在设计一种使用近红外光谱（NIRS）结合多元方法分析 13 个乳香树种群的内源性植物激素的稳健方法。在吸收模式（10000-4000cm-1）下记录 NIRS 数据，以建立偏最小二乘回归模型（校准集 70%）。然后，将模型作为测试集进行外部交叉验证（30%），以检查其在应用于量化 13 个不同乳香树种群未知植物激素含量之前的预测能力。结果表明，植物激素含量存在显著差异，不同种群中表现出 SA>GA/IAA>kinetin 的趋势。在哈西克的第 13 种群（Pop13）和多瓦卡的第 2 种群（Pop2）中，SA 和 GA 的含量明显较高，多瓦卡是达夫地区乳香树覆盖的最极端地区。当对来自 13 个种群的样本进行高效液相色谱-质谱联用和气相色谱-选择离子监测分析时，也发现了类似的植物激素浓度趋势。目前的分析为评估植物健康提供了一种替代工具，这对于原位繁殖和监测树木种群的生长动态可能很重要。
