Bellvert Joaquim, Nieto Héctor, Pelechá Ana, Jofre-Čekalović Christian, Zazurca Lourdes, Miarnau Xavier
Efficient Use of Water in Agriculture Program, Institute of Agrifood Research and Technology, Fruitcentre, Parc Científic i Tecnològic Agroalimentari de Lleida, Lleida, Spain.
Complutum Tecnologías de la Información Geográfica, Madrid, Spain.
Front Plant Sci. 2021 Mar 10;12:608967. doi: 10.3389/fpls.2021.608967. eCollection 2021.
One of the objectives of many studies conducted by breeding programs is to characterize and select rootstocks well-adapted to drought conditions. In recent years, field high-throughput phenotyping methods have been developed to characterize plant traits and to identify the most water use efficient varieties and rootstocks. However, none of these studies have been able to quantify the behavior of crop evapotranspiration in almond rootstocks under different water regimes. In this study, remote sensing phenotyping methods were used to assess the evapotranspiration of almond cv. "Marinada" grafted onto a rootstock collection. In particular, the two-source energy balance and Shuttleworth and Wallace models were used to, respectively, estimate the actual and potential evapotranspiration of almonds grafted onto 10 rootstock under three different irrigation treatments. For this purpose, three flights were conducted during the 2018 and 2019 growing seasons with an aircraft equipped with a thermal and multispectral camera. Stem water potential (Ψ ) was also measured concomitant to image acquisition. Biophysical traits of the vegetation were firstly assessed through photogrammetry techniques, spectral vegetation indices and the radiative transfer model PROSAIL. The estimates of canopy height, leaf area index and daily fraction of intercepted radiation had root mean square errors of 0.57 m, 0.24 m m and 0.07%, respectively. Findings of this study showed significant differences between rootstocks in all of the evaluated parameters. Cadaman and Garnem had the highest canopy vigor traits, evapotranspiration, Ψ and kernel yield. In contrast, Rootpac 20 and Rootpac R had the lowest values of the same parameters, suggesting that this was due to an incompatibility between plum-almond species or to a lower water absorption capability of the rooting system. Among the rootstocks with medium canopy vigor, Adesoto and IRTA 1 had a lower evapotranspiration than Rootpac 40 and Ishtara. Water productivity (WP) (kg kernel/mm water evapotranspired) tended to decrease with Ψ , mainly in 2018. Cadaman and Garnem had the highest WP, followed by INRA GF-677, IRTA 1, IRTA 2, and Rootpac 40. Despite the low Ψ of Rootpac R, the WP of this rootstock was also high.
育种计划开展的许多研究的目标之一是对适应干旱条件的砧木进行特征描述和选择。近年来，已开发出田间高通量表型分析方法来描述植物性状，并识别水分利用效率最高的品种和砧木。然而，这些研究均未能量化不同水分条件下杏仁砧木的作物蒸散行为。在本研究中，采用遥感表型分析方法评估嫁接到一组砧木上的“Marinada”品种杏仁的蒸散情况。具体而言，分别使用双源能量平衡模型以及Shuttleworth和Wallace模型，估算在三种不同灌溉处理下嫁接到10种砧木上的杏仁的实际蒸散量和潜在蒸散量。为此，在2018年和2019年生长季期间，使用配备了热成像和多光谱相机的飞机进行了三次飞行监测。在图像采集的同时还测量了茎水势（Ψ ）。首先通过摄影测量技术、光谱植被指数和辐射传输模型PROSAIL评估植被的生物物理性状。冠层高度、叶面积指数和每日截获辐射比例的估算值的均方根误差分别为0.57米、0.24平方米和0.07%。本研究结果表明，在所有评估参数方面，砧木之间存在显著差异。卡达曼和加内姆的冠层活力性状、蒸散量、Ψ 和果仁产量最高。相比之下，Rootpac 20和Rootpac R在相同参数方面的值最低，这表明这是由于李属 - 扁桃属物种之间不亲和，或者是根系吸水能力较低所致。在冠层活力中等的砧木中，阿德索托和IRTA 1的蒸散量低于Rootpac 40和伊斯塔拉。水分生产率（WP）（每毫米蒸散水分的果仁产量，单位：千克）往往随Ψ 降低，主要在2018年如此。卡达曼和加内姆的WP最高，其次是INRA GF - 677、IRTA 1、IRTA 2和Rootpac 40。尽管Rootpac R的Ψ 较低，但其砧木的WP也很高。
