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Background and Aims Germplasm with diverse, agronomically relevant traits forms the foundation of a successful plant breeding programme. Since 1993, the United Nations has been advocating the implementation of the Convention on Biological Diversity (CBD) and the subsequent 2002 Bonn Guidelines as international best practice on germplasm collection and use. In 2006, a European team made an expedition to Asia to collect wild germplasm of Miscanthus , a C4 perennial rhizomatous grass, for breeding an environmentally adaptable, resilient and high-yielding bioenergy crop. We outline general aspects of germplasm collection, conservation, breeding and biomass production evaluation while following the CBD's guidelines, respecting biodiversity and conservation needs, and the ethical use of genetic resources. Methods Effective protocols, quarantine, methods for collecting seed and rhizomes, and a genebank for conservation were established. Versatile informatics and database architecture were used to assist in selection, flowering synchronization, crossing, evaluation, phenotyping and data integration. Approaches were formulated to comply with the CBD guidelines. Key Results A total of 303 accessions of M. sinensis , M. sacchariflorus and M. floridulus were collected from 158 geographically and environmentally diverse locations. These species were shown to accumulate different amounts of aerial biomass due to combinations of stem count, height and thickness. Progeny from one interspecies cross accumulated more biomass in early trials and has shown double the yield performance in years 3–4 compared with the existing commercial cultivar M. × giganteus. An example of an F1 hybrid has already demonstrated the long-term potential of exploiting this collection for a breeding programme. Conclusions By conforming to the CBD principles, the authors' international collaboration provides a practical example of implementing the CBD. The collection widened the genetic diversity of Miscanthus available to allow for breeding of novel hybrids that exhibit more diverse traits to increase yield and resilience for growth on marginal land and in climate-challenged environments. [ABSTRACT FROM AUTHOR]

Background and aims: Belowground carbon (C) inputs are a major source of soil organic carbon (SOC) in terrestrial ecosystems, and substrate C:N ratios drive SOC stabilisation. In perennial systems, quantitative information on seasonal dynamics of belowground biomass is scarce, but necessary, e.g. to improve SOC modelling and representative sampling. Methods: Seasonal dynamics and depth distribution of belowground biomass C and N of extensive grassland and Miscanthus on sandy soil were estimated. Core samples (1 m depth) were taken six times in 1 year. Miscanthus-derived SOC was quantified using 13C natural abundance. Results: Grassland and Miscanthus differed strongly in belowground biomass C (2.5 ± 0.3 vs. 7.3 ± 1.1 Mg ha−1) and C:N ratios (28.6 ± 0.5 vs. 60 ± 3.3). Peak grassland belowground biomass C and N stocks occurred in summer, while those of rhizomatous Miscanthus were in winter due to different strategies of resource allocation. Grassland roots showed a strong seasonal pattern of C:N ratios, indicating N remobilisation. Miscanthus-derived topsoil SOC was low relative to the high belowground biomass, indicating a slow transfer of rhizome carbon to bulk SOC. Conclusions: Representative belowground biomass sampling of perennials should take seasonal dynamics into account, especially in system comparisons. Furthermore, C inputs from rhizome and roots should be estimated separately owing to likely differences in turnover times. [ABSTRACT FROM AUTHOR]

Miscanthus is a genus of perennial rhizomatous grasses with C4 photosynthesis which is indigenous in a wide geographic range of Asian climates. The sterile clone, Miscanthus × giganteus (M. × giganteus), is a naturally occurring interspecific hybrid that has been used commercially in Europe for biomass production for over a decade. Although, M. × giganteus has many outstanding performance characteristics including high yields and low nutrient offtakes, commercial expansion is limited by cloning rates, slow establishment to a mature yield, frost, and drought resistance. In this paper, we evaluate the performance of 13 novel germplasmtypes alongsideM. × giganteus and horticultural "Goliath" in trials in six sites (in Germany, Russia, The Netherlands, Turkey, UK, and Ukraine). Mean annual yields across all the sites and genotypes increased from 2.3 ± 0.2 t dry matter ha-1 following the first year of growth, to 7.3 ± 0.3, 9.5 ± 0.3, and 10.5 ± 0.2 t dry matter ha-1 following the second, third, and fourth years, respectively. The highest average annual yields across locations and four growth seasons were observed for M. × giganteus (9.9 ± 0.7 t dry matter ha-1) and interspecies hybrid OPM-6 (9.4 ± 0.6 t dry matter ha-1). The best of the new hybrid genotypes yielded similarly to M. × giganteus at most of the locations. Significant effects of the year of growth, location, species, genotype, and interplay between these factors have been observed demonstrating strong genotype × environment interactions. The highest yields were recorded in Ukraine. Time needed for the crop establishment varied depending on climate: in colder climates such as Russia the crop has not achieved its peak yield by the fourth year, whereas in the hot climate of Turkey and under irrigation the yields were already high in the first growing season. We have identified several alternatives to M. × giganteus which have provided stable yields across wide climatic ranges, mostly interspecies hybrids, and also Miscanthus genotypes providing high biomass yields at specific geographic locations. Seed-propagated interspecific and intraspecific hybrids, with high stable yields and cheaper reliable scalable establishment remain a key strategic objective for breeders. [ABSTRACT FROM AUTHOR]

Miscanthus is a woody rhizomatous C4 grass that can be used as a CO2 neutral biofuel resource. It has potential to grow in marginal areas such as saline soils, avoiding competition for arable lands with food crops. This study explored genetic diversity for salt tolerance in Miscanthus and discovered mechanisms and traits that can be used to improve the yield under salt stress. Seventy genotypes of Miscanthus (including 57 M. sinensis, 5 M. sacchariflorus, and 8 hybrids) were evaluated for salt tolerance under saline (150 mM NaCl) and normal growing conditions using a hydroponic system. Analyses of shoot growth traits and ion concentrations revealed the existence of large variation for salt tolerance in the genotypes. We identified genotypes with potential for high biomass production both under control and saline conditions that may be utilized for growth under marginal, saline conditions. Several relatively salt tolerant genotypes had clearly lower Na+ concentrations and showed relatively high K+/Na+ ratios in the shoots under salt stress, indicating that a Na+ exclusion mechanism was utilized to prevent Na+ accumulation in the leaves. Other genotypes showed limited reduction in leaf expansion and growth rate under saline conditions, which may be indicative of osmotic stress tolerance. The genotypes demonstrating potentially different salt tolerance mechanisms can serve as startingmaterial for breeding programs aimed at improving salinity tolerance of Miscanthus. [ABSTRACT FROM AUTHOR]

Fifteen miscanthus genotypes selected by European plant breeders were field tested in Denmark over a three-year period. The genotypes belonged to four groups: 1) M. x giganteus 2) M. sacchariflorus 3) Miscanthus hybrids and 4) Pure M. sinensis . All genotypes established well during the first summer with a maximum of 10% plant loss. Survival during the first winter varied from no survival of M. x giganteus to 85-99% survival of most pure M. sinensis and of the hybrids. Biomass yield harvested in October-November increased each year to a mean of 10.8 tonnes DM/ha in 1999. The highest yield was 18.5 tonnes DM/ha. Delaying harvest until February 2000 decreased moisture content from a genotype mean of 63% in October to 29%, and decreased mean yield by 35%. The contents of K, Cl and ash were significantly lower at delayed harvest, while N and S contents only decreased slightly. Genotype differences in time of flowering and in mineral contents are described. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to measure the chemical composition and morphological and mechanical properties, and to determine the contribution of different tissue components and chemical constituents to the modulus of elasticity of Miscanthus. Randomly selected stems of Miscanthus ‘Giganteus’, 10 numbered clones and 6 named cultivars of M. sinensis were harvested in February 1999. Determination of morphological characteristics included counting the number of internodes, measurement of the length of stems and internodes, and size of outer and inner diameter. Culm wall thickness, cross sectional stem area and moment of inertia were calculated, and modulus of elasticity was measured using a three point method. Chemical analysis included determination of the concentration of dry matter, cellulose, lignin, and ashes. Studies of anatomy encompassed determination of number of vascular bundles, area of parenchyma vascular bundles, and outer heavily lignified ring (outer ring). Substantial variations and significant differences between genotypes were found for all morphological and anatomical characteristics and for concentrations of chemical constituents except dry matter. A stepwise regression analysis was carried out on the relationship between modulus of elasticity as the dependent variable, and the morphological characteristics, anatomical characteristics, and the concentration of chemical constituents as independent variables. Modulus of elasticity depended significantly of the area parenchyma vascular bundles and outer heavily lignified tissue (outer ring) and of the concentration of lignin and cellulose. Based on the measured characteristics it was hypothesized that the cultivar ‘Purpurescens’ may have the highest lodging resistance followed by ‘Braunschweigh’ and ‘Giganteus’. [Copyright &y& Elsevier]

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process. [ABSTRACT FROM AUTHOR]

Miscanthus is a high-yielding lignocellulosic perennial biomass crop. The low multiplication rate of clonal rhizome propagation is a bottleneck to upscaling plantation areas of feedstock needed to supply and expand the bioeconomy. Novel seeded Miscanthus hybrids are currently being developed to overcome this bottleneck by increasing annual multiplication rates from approximately 10 to over 1000 times. We describe a series of field experiments in southern Italy using agronomic methods to optimise multiplication rates through (i) planting configurations and densities, (ii) ratio of seed parents to pollen parents (iii) supplemental pre-dawn misting to increase humidity during pollination. In these trials the seed-bearing M. sinensis started flowering 2–3 weeks earlier than the M. sacchariflorus pollen parent. Earlier experiments indicated that flowering in M. sacchariflorus was mostly determined by photoperiod while in M. sinensis it was modulated by endogenous signals. Consequently, a second set of experiments were conducted to delay flowering time in M. sinensis : (iv) mid-season stem cut back, (v) oversupply of nitrogen, and (vi) undersupply of water. Across all treatments and years, the multiplication rates varied from 140 to 1300 seeds m². Reducing the proportion of the pollen parent plants (M. sacchariflorus) from 50 % to 25 % did not reduce seed yield per plant. This therefore increases the seed yield per m² and reduces seed production upscaling costs. Flowering time and duration in M. sinensis was significantly impacted by mid-season cutting and water stress, but not by nitrogen supply rates. Mid-season shoot cutting reduced number of flowers per plant (77 %), seed quantity (47 %), seed size (46 %), and resulted in seeds with a low germination rate of 39 %. High M. sinensis planting densities produced higher seed yields in the first year. However, in subsequent years higher density plots were more susceptible to autumn lodging lowering seed production by loss of panicles. Pre-dawn misting to prolong pollen life and stigma receptivity had no significant effects on seed production. This study demonstrates the importance of flowering time synchronization in the open field for commercial seed production. The limited effect of agronomic efforts to reduce the interspecies flowering time gap emphasises the importance of genetic factors in controlling flowering time. The most impactful intervention to change flowering time and improve parental synchronisation was mid-season cutting, while this method reduced seed production when applied to the seed parent it could be ideal for pollen parents. • Commercially relevant in field optimisation of Miscanthus hybrid seed production. • Field flowering synchronisation manipulation for production of interspecies seed. • Parental ratios ≥ 3:1 can increase seed per m² without impacting pollination rate. • Under field conditions reduced watering delayed M. sinensis flowering. • Mid-season cutting was most effective for flowering delay but reduced seed set. [ABSTRACT FROM AUTHOR]