Lazarević Boris, Šatović Zlatko, Nimac Ana, Vidak Monika, Gunjača Jerko, Politeo Olivera, Carović-Stanko Klaudija
Department of Plant Nutrition, Faculty of Agriculture, University of Zagreb, Zagreb, Croatia.
Centre of Excellence for Biodiversity and Molecular Plant Breeding (CroP-BioDiv), Faculty of Agriculture, University of Zagreb, Zagreb, Croatia.
Front Plant Sci. 2021 Feb 18;12:629441. doi: 10.3389/fpls.2021.629441. eCollection 2021.
Basil is one of the most widespread aromatic and medicinal plants, which is often grown in drought- and salinity-prone regions. Often co-occurrence of drought and salinity stresses in agroecosystems and similarities of symptoms which they cause on plants complicates the differentiation among them. Development of automated phenotyping techniques with integrative and simultaneous quantification of multiple morphological and physiological traits enables early detection and quantification of different stresses on a whole plant basis. In this study, we have used different phenotyping techniques including chlorophyll fluorescence imaging, multispectral imaging, and 3D multispectral scanning, aiming to quantify changes in basil phenotypic traits under early and prolonged drought and salinity stress and to determine traits which could differentiate among drought and salinity stressed basil plants. "Genovese" was grown in a growth chamber under well-watered control [45-50% volumetric water content (VWC)], moderate salinity stress (100 mM NaCl), severe salinity stress (200 mM NaCl), moderate drought stress (25-30% VWC), and severe drought stress (15-20% VWC). Phenotypic traits were measured for 3 weeks in 7-day intervals. Automated phenotyping techniques were able to detect basil responses to early and prolonged salinity and drought stress. In addition, several phenotypic traits were able to differentiate among salinity and drought. At early stages, low anthocyanin index (ARI), chlorophyll index (CHI), and hue (HUE ), and higher reflectance in red (R ), reflectance in green (R ), and leaf inclination (LINC) indicated drought stress. At later stress stages, maximum fluorescence (F ), HUE , normalized difference vegetation index (NDVI), and LINC contribute the most to the differentiation among drought and non-stressed as well as among drought and salinity stressed plants. ARI and electron transport rate (ETR) were best for differentiation of salinity stressed plants from non-stressed plants both at early and prolonged stress.
罗勒是分布最广泛的芳香植物和药用植物之一，常生长于易干旱和盐碱化的地区。农业生态系统中干旱和盐胁迫常常同时出现，且它们对植物造成的症状相似，这使得区分二者变得复杂。开发能够综合且同时量化多种形态和生理特征的自动化表型分析技术，有助于在整株植物水平上早期检测和量化不同胁迫。在本研究中，我们使用了不同的表型分析技术，包括叶绿素荧光成像、多光谱成像和三维多光谱扫描，旨在量化罗勒在早期和长期干旱及盐胁迫下表型特征的变化，并确定能够区分干旱和盐胁迫罗勒植株的特征。“热那亚”罗勒在生长室中培养，设置了充分浇水的对照处理[体积含水量（VWC）为45 - 50%]、中度盐胁迫（100 mM NaCl）、重度盐胁迫（200 mM NaCl）、中度干旱胁迫（25 - 30% VWC）和重度干旱胁迫（15 - 20% VWC）。每隔7天测量一次表型特征，持续3周。自动化表型分析技术能够检测罗勒对早期和长期盐胁迫及干旱胁迫的响应。此外，一些表型特征能够区分盐胁迫和干旱胁迫。在早期阶段，低花青素指数（ARI）、叶绿素指数（CHI）和色调（HUE），以及较高的红光反射率（R）、绿光反射率（R）和叶片倾斜度（LINC）表明存在干旱胁迫。在胁迫后期，最大荧光（F）、HUE、归一化植被指数（NDVI）和LINC对区分干旱与非胁迫植株以及干旱与盐胁迫植株贡献最大。ARI和电子传递速率（ETR）在早期和长期胁迫下最能有效区分盐胁迫植株与非胁迫植株。
