Genetic Variability of Morphological, Flowering, and Biomass Quality Traits in Hemp (Cannabis sativa L.)
Petit, Jordi ; Salentijn, Elma M.J. ; Paulo, Maria João ; Thouminot, Claire ; Dinter, Bert Jan van; Magagnini, Gianmaria ; Gusovius, Hans Jörg ; Tang, Kailei ; Amaducci, Stefano ; Wang, Shaoliang ; Uhrlaub, Birgit ; Müssig, Jörg ; Trindade, Luisa M. - \ 2020
Frontiers in Plant Science 11 (2020). - ISSN 1664-462X
Cannabis sativa - cell wall composition - fiber quality - flowering time - genetic variability - genotype-by-environment (G×E) interactions - hemp - sex determination
Hemp (Cannabis sativa L.) is a bast-fiber crop well-known for the great potential to produce sustainable fibers. Nevertheless, hemp fiber quality is a complex trait, and little is known about the phenotypic variability and heritability of fiber quality traits in hemp. The aim of this study is to gain insights into the variability in fiber quality within the hemp germplasm and to estimate the genetic components, environmental components, and genotype-by-environment (G×E) interactions on fiber quality traits in hemp. To investigate these parameters, a panel of 123 hemp accessions was phenotyped for 28 traits relevant to fiber quality at three locations in Europe, corresponding to climates of northern, central, and southern Europe. In general, hemp cultivated in northern latitudes showed a larger plant vigor while earlier flowering was characteristic of plants cultivated in southern latitudes. Extensive variability between accessions was observed for all traits. Most cell wall components (contents of monosaccharides derived from cellulose and hemicellulose; and lignin content), bast fiber content, and flowering traits revealed large genetic components with low G×E interactions and high broad-sense heritability values, making these traits suitable to maximize the genetic gains of fiber quality. In contrast, contents of pectin-related monosaccharides, most agronomic traits, and several fiber traits (fineness and decortication efficiency) showed low genetic components with large G×E interactions affecting the rankings across locations. These results suggest that pectin, agronomic traits, and fiber traits are unsuitable targets in breeding programs of hemp, as their large G×E interactions might lead to unexpected phenotypes in untested locations. Furthermore, all environmental effects on the 28 traits were statistically significant, suggesting a strong adaptive behavior of fiber quality in hemp to specific environments. The high variability in fiber quality observed in the hemp panel, the broad range in heritability, and adaptability among all traits prescribe positive prospects for the development of new hemp cultivars of excellent fiber quality.
A comprehensive study of planting density and nitrogen fertilization effect on dual-purpose hemp (Cannabis sativa L.) cultivation
Tang, K. ; Struik, P.C. ; Yin, X. ; Calzolari, D. ; Musio, S. ; Thouminot, C. ; Bjelková, M. ; Stramkale, V. ; Magagnini, G. ; Amaducci, S. - \ 2017
Industrial Crops and Products 107 (2017). - ISSN 0926-6690 - p. 427 - 438.
Critical dilution curve - Density - Hemp (Cannabis sativa L.) - Nitrogen - Seed - Stem
Harvesting hemp (Cannabis sativa L.) for both stems and seeds is now a common practice in Europe while crop management strategies for dual-purpose hemp cultivation have not been properly addressed so far. In the present study, the effects of planting density and nitrogen fertilization on hemp stem and seed yields were tested with the cultivars Futura 75 and/or Bialobrzeskie in eight contrasting environments (Italy in 2013; Italy and Latvia in 2014; Italy (two sites), Latvia, the Czech Republic, and France in 2015). Stem yield ranged between 1.3 and 22.3Mgha-1. The effects of planting density and nitrogen fertilization on stem yield did not interact significantly with each other, or with cultivar and harvest time. Increasing planting density from 30 to 120 plants m-2 and increasing nitrogen fertilization rate from 0 to 60kgNha-1 increased stem yield by 29% and 32%, respectively. Further increase in planting density and nitrogen fertilization did not result in a significant increase in stem yield. Seed yield ranged from 0.3 to 2.1Mgha-1. The seed yield was not affected significantly by planting density between 30 and 240 plants m-2. Although the seed yield showed an increasing trend with increasing nitrogen fertilization, the effects of nitrogen fertilization on seed yield were not statistically significant.To grow hemp as a dual-purpose crop it is recommended to plant 90-150 plants m-2 across all tested environments. Nitrogen fertilization rate at 60kg N ha-1 was generally sufficient in the tested environments whereas further optimization of nitrogen fertilization requires accurate assessment of plant nitrogen status. To facilitate assessing plant nutritional status, a critical nitrogen dilution curve was determined for hemp and a practical method to determine nitrogen nutritional status was discussed.