Genetic by environment interactions of two North American Salix species assessed for coppice yield and components of growth on three sites of varying quality

• Published in: Trees (Berlin, West) West), 2014-10, Vol.28 (5), p.1401-1411
• Main Authors: Mosseler, A, Major, J. E, Labrecque, M
• Format: Article
• Language: English
• Subjects: Agriculture; Biomass; biomass production; Biomedical and Life Sciences; clones; coal; Coal mines; coppicing; field experimentation; Field tests; Forestry; genotype; genotype-environment interaction; Genotypes; growth traits; heat sums; Life Sciences; Original Paper; Overburden; Plant Anatomy/Development; Plant Pathology; Plant Physiology; Plant Sciences; Salix; Salix discolor; shale; Soil nutrients; Soil properties; temperature; water holding capacity
• ISSN: 0931-1890; 1432-2285
• DOI: 10.1007/s00468-014-1043-9

KEY MESSAGE: Field testing of different willow species, and promising genotypes within a species, can maximize biomass yield and quality traits due to strong genotype by environment interactions. Coppice yield and components of growth were quantified in eight clones of two widely distributed North American willows, Salix discolor (DIS) and S. eriocephala (ERI), in common-garden field tests on three sites of varying quality. Both species and clones within species varied significantly across different sites and interacted with site for plant yield and components of growth traits. At the species level, ERI was significantly more productive than DIS on the two most productive sites (85 and 57 % greater, respectively), but on the poorest site, a shale coal mine overburden, species ranking was reversed, with DIS showing a 60 % greater biomass yield than ERI. These sites had similar mean temperature, growing degree days, and seasonal precipitation. Site quality differences were thus most probably driven by soil nutrients, physical traits, and water-holding capacity quantified by 13 soil properties, 12 of which were significantly different and showed fairly consistent ranking among sites. At the clonal level, growth trends and differences were mostly consistent among clones across the three test sites, with the exception of one clone of DIS and to a lesser extent a clone of ERI, which showed abnormally strong clone by site interaction for specific growth traits. Productivity reached as high as 6.0 kg green mass in 2-year-old coppices for a clone from each of DIS and ERI on the most productive site. The strong expression of genetic by environment interactions at both the species and clonal levels suggests that biomass production can be optimized by taking advantage of such interactions and highlights the need for testing not only different species, but also a number of clones within a species before selecting clones for biomass production on different site types. Our results highlight variation in coppice form and the potential for genetic selection both among and within species.