Environmental Modulation of Mini-Clonal Gardens for Cutting Production and Propagation of Hard- and Easy-to-Root Eucalyptus spp

Abstract

Clonal Eucalyptus propagation is essential for various industry sectors. It requires cuttings to successfully develop adventitious roots (ARs). Environmental conditions are influential on AR development and may be altered to modulate the productivity of hard-to-root clones. The current knowledge gap in research on the physiological patterns underlying commercial-scale propagation results hinders the design of novel strategies. This study aimed to identify patterns of variation in AR-relevant parameters in contrasting seasons and species with distinct rooting performances. E. dunnii and E. ×urograndis (hard- (hardR) and easy-to-root (easyR), respectively) mini-stumps were subjected to light modulation treatments and to mini-tunnel use (MT) for a year. The treatment impact on the branching and rooting rates was recorded. The carbohydrate content, AR-related gene expression, and mineral nutrition profiles of cuttings from the control (Ctrl) and treated mini-stumps were analyzed. Light treatments were often detrimental to overall productivity, while MTs had a positive effect during summer, when it altered the cutting leaf nutrient profiles. Species and seasonality played large roles in all the assessed parameters. E. ×urograndis was particularly susceptible to seasonality, and its overall superior performance correlated with changes in its gene expression profile from excision to AR formation. These patterns indicate fundamental differences between easyR and hardR clones that contribute to the design of data-driven management strategies aiming to enhance propagation protocols.

A Comprehensive Review Uncovering the Challenges and Advancements in the In Vitro Propagation of Eucalyptus Plantations

“…Moreover, the F1 hybrids from interspecific breeding show heterosis. Successful attempts to achieve commercial-scale plantations have been made for some species (E. deglupta, E. grandis, E. camaldulensis, and E. pellita) agile to tropical and subtropical regions with high rainfall via macro-and microcuttings [10][11][12]. For those species unable to rapidly propagate using these methods, tissue culture is a propitious approach [13].…”

A Proximal Sensor-Based Approach for Clean, Fast, and Accurate Assessment of the Eucalyptus spp. Nutritional Status and Differentiation of Clones

“…In Brazil, it accounts for 78% of the national forestry sector, worth over USD 21 billion in 2021 [ 1 ]. From cellulose and charcoal to timber and energy, many industry sectors depend on high-quality woody biomass provided by Eucalyptus planted forests [ 2 ]. In addition to being rich in essential oils (EO) [ 3 ], Eucalyptus has a great diversity of biological, pharmaceutical, and cosmetic applications [ 4 ].…”

Anais do Congresso Plantações Florestais.

“…High-quality seedlings, particularly of eucalyptus, favor final products with greater economic value (García-Quincoces et al, 2023). However, some species, such as Corymbia citriodora, exhibit recalcitrance to rooting , which can hinder or even make it unfeasible to propagate high-value genotypes for the industry through cuttings (Vilasboa et al, 2022).…”