Characterization of phenology, physiology, morphology and biomass traits across a broad Euro‐Mediterranean ecotypic panel of the lignocellulosic feedstock Arundo donax

Abstract

Giant reed (Arundo donax L.) is a perennial rhizomatous grass, which has attracted great attention as a potential lignocellulosic feedstock for bioethanol production due to high biomass yield in marginal land areas, high polysaccharide content and low inhibitor levels in microbial fermentations. However, little is known about the trait variation that is available across a broad ecotypic panel of A. donax nor the traits that contribute most significantly to yield and growth in drought prone environments. A collection of 82 ecotypes of A. donax sampled across the Mediterranean basin was planted in a common garden experimental field in Savigliano, Italy. We analysed the collection using 367 clumps representing replicate plantings of 82 ecotypes for variation in 21 traits important for biomass accumulation and to identify the particular set of ecotypes with the most promising potential for biomass production. We measured morpho‐physiological, phenological and biomass traits and analysed causal relationships between traits and productivity characteristics assessed at leaf and canopy levels. The results identified differences among the 82 ecotypes for all studied traits: those showing the highest level of variability included stomatal resistance, stem density (StN), stem dry mass (StDM) and total biomass production (TotDM). Multiple regression analysis revealed that leaf area index, StDM, StN, number of nodes per stem, stem height and diameter were the most significant predictors of TotDM and the most important early selection criteria for bioenergy production from A. donax. These traits were used in a hierarchical cluster analysis to identify groups of similar ecotypes, and a selection was made of promising ecotypes for multiyear and multisite testing for biomass production. Heritability estimates were significant for all traits. The potential of this ecotype collection as a resource for studies of germplasm diversity and for the analysis of traits underpinning high productivity of A. donax is highlighted.

UAV-Based LiDAR for High-Throughput Determination of Plant Height and Above-Ground Biomass of the Bioenergy Grass Arundo donax

“…The study area was located in Savigliano, northern Italy, (44 • 35 N, 07 • 37 E, 349 m above sea level) ( Figure 1a). Three clones of A. donax (named hereafter EcoA, EcoB, and EcoC) were selected from a set of 82 EuroMediterranean ecotypes [22] and vegetatively propagated by rhizomes. The selected ecotypes originated from three contrasting environments: EcoA was collected from the coastal habitat of Attica region (southern Greece), characterized by typical warm Mediterranean climate; EcoB originated from the coastal habitat of southern Dalmatia region (southern Croatia), characterized by temperate oceanic climate; and EcoC was collected from the hilly area of Viseu district (northern Portugal), characterized by temperate Mediterranean climate.…”

Integrated lignocellulosic value chains in a growing bioeconomy: Status quo and perspectives

“…The long‐term soil rest reduces the risk of soil erosion and leads to soil carbon and humus accumulation, thus improving soil fertility and potentially improving degraded lands (Lewandowski, ). PBC can be integrated well into farming systems and provide them with additional biomass for on‐farm use or as cash crops. PBC have the highest productivity of all biomass production systems in Europe. There are promising candidate PBC for temperate (see Clifton‐Brown et al, ; Hoeber et al, ) and Mediterranean (see Fabbrini et al, ) European climates, including switchgrass, miscanthus, giant reed, willow and poplar. Breeding programs are in place for most relevant PBC.…”

“…Breeding programs are in place for most relevant PBC. These exploit the genetic variability and have already delivered genotypes at varying levels of advancement (Clifton‐Brown et al, ; Fabbrini et al, ; Hoeber et al, ) The chemical composition and physical properties of PBC biomass can be tailored to biomass utilization chains by the optimization of harvest time (Mangold, Lewandowski, & Kiesel, , ), appropriate selection of available cultivars (Schäfer, Sattler, Iqbal, Lewandowski, & Bunzel, ) and, in the long term, through breeding programs (see Clifton‐Brown et al, ). Biomass from PBC thus has a more consistent composition than biomass from wastes, which come from a variety of sources, and is therefore more suitable for conversion pathways with specific quality requirements.…”

“…The supply of sustainably produced biomass is the prerequisite for a lignocellulosic value chain to perform well. It can be provided from sustainable forestry and from agricultural production, with agricultural residues and perennial biomass crops (PBC) being the most favourable resources (Clifton‐Brown et al, ; Fabbrini et al, ; Hoeber et al, ). PBC can be integrated into existing farming systems using less favourable land or land marginal for food crop production, with the additional provision of various ecological benefits (Wagner et al, ).…”

Biobased value chains for a growing bioeconomy

“…Breeding programs are in place for the most relevant PBC. These exploit the genetic variability and have delivered genotypes at varying levels of advancement (Clifton‐Brown et al, ; Fabbrini et al, ). The optimal integration of biomass production and conversion requires advanced breeding (see e.g., Clifton‐Brown et al, ) that tailors the biomass to user needs, resulting in improved pretreatment and conversion efficiencies.…”