Department Territorio e Sistemi Agro Forestali (TESAF), University of Padova, Viale dell'Università 16, 350120 Legnaro, Italy.
Department of Life Science and Systems Biology, University of Torino, Viale Mattioli, 25, 10125 Torino, Italy.
Tree Physiol. 2021 Nov 8;41(11):2022-2033. doi: 10.1093/treephys/tpab069.
Climate change and the global economy impose new challenges in the management of food-producing trees and require studying how to model plant physiological responses, namely growth dynamics and phenology. Hazelnut (Corylus avellana L.) is a multi-stemmed forest species domesticated for nut production and now widely spread across different continents. However, information on stem growth and its synchronization with leaf and reproductive phenology is extremely limited. This study aimed at (i) defining the sequencing of radial growth phases in hazelnut (onset, maximum growth and cessation) and the specific temperature triggering stem growth; and (ii) combining the stem growth phases with leaf and fruit phenology. Point dendrometers were installed on 20 hazelnut trees across eight orchards distributed in the Northern and Southern hemisphere during a period of three growing seasons between 2015 and 2018. The radial growth variations and climatic parameters were averaged and recorded every 15 min. Leaf and reproductive phenology were collected weekly at each site. Results showed that stem radial growth started from day of year 84 to 134 in relation to site and year but within a relatively narrow range of temperature (from 13 to 16.5 °C). However, we observed a temperature-related acclimation in the cultivar Tonda di Giffoni. Maximum growth always occurred well before the summer solstice (on average 35 days) and before the maximum annual air temperatures. Xylogenesis developed rapidly since the time interval between onset and maximum growth rate was about 3 weeks. Importantly, the species showed an evident delay of stem growth onset with respect to leaf emergence (on average 4-6 weeks) rarely observed in tree species. These findings represent the first global analysis of radial growth dynamics in hazelnut, which is an essential step for developing models on orchard functioning and management on different continents.
气候变化和全球经济给粮食生产树木的管理带来了新的挑战，需要研究如何模拟植物的生理响应，即生长动态和物候学。榛子（Corylus avellana L.）是一种多茎森林物种，经过驯化用于坚果生产，现在广泛分布在不同的大陆。然而，关于茎生长及其与叶片和生殖物候同步的信息极其有限。本研究旨在：(i) 确定榛子径向生长阶段的顺序（开始、最大生长和停止）和触发茎生长的特定温度；(ii) 将茎生长阶段与叶片和果实物候相结合。在 2015 年至 2018 年的三个生长季节期间，在分布在北半球和南半球的八个果园中，在 20 棵榛树上安装了点测微计。将径向生长变化和气候参数平均并记录每 15 分钟一次。每周在每个地点收集叶片和生殖物候。结果表明，茎的径向生长开始于生长日第 84 天至第 134 天，与地点和年份有关，但在相对较窄的温度范围内（13 至 16.5°C）。然而，我们观察到在 Tonda di Giffoni 品种中存在与温度相关的适应。最大生长总是在夏至之前（平均 35 天）和年最高气温之前发生。木质部形成迅速发展，因为起始和最大生长速率之间的时间间隔约为 3 周。重要的是，该物种的茎生长起始与叶片出现之间存在明显的延迟（平均 4-6 周），这在树种中很少观察到。这些发现代表了榛子径向生长动态的首次全球分析，这是在不同大陆开发果园功能和管理模型的重要步骤。
