Arundo species are perennial rhizomatous grass belonging to the tribe Arundinae (subfamily Arundinoideae: Poaceae) (Barker et al., 1999). Arundo donax, in particular, is one of the largest of the herbaceous grasses (Perdue, 1958), growing in dense clumps and attaining heights of up to 8–9 m (Lewandowski et al., 2003). With such impressive growth rates, A. donax is a leading candidate for cultivated biomass in Mediterranean climates (Angelini et al., 2009; Cosentino et al., 2006) and is also being considered as an energy crop in North America (Gilbert at al., 2008; Lewandowski et al., 2003). Many of the advantages of A. donax as an energy crop include a high yield potential (up to 63.1 Mg·ha−1 of dry matter), high lignin and cellulose content, rapid growth rate (up to 0.7 m·week−1 under favorable conditions), high carbon sequestration, widely adaptable to marginal sites, low irrigation and nutrient requirements, and minimal soil tillage, (Lewandowski et al., 2003).
Arundo donax is generally found in alluvial, riparian habitats, such as along the borders of lakes or ditches, but can tolerate a wide range of diverse ecological conditions (Perdue, 1958; Vollmer et al., 2008). The native origin of A. donax has been variously reported as southern Asia (Bell, 1997; Dudley, 2000), eastern Asia (Polunin and Huxley, 1987), and countries surrounding the Mediterranean Sea (Perdue, 1958), though a recent study has provided evidence that A. donax likely originated in Asia and subsequently spread into the Mediterranean region (Mariani et al., 2010). A. donax also has been widely dispersed by humans throughout subtropical and warm-temperate regions for diverse applications including musical instruments, paper and pulp, and woven baskets (Perdue, 1958). In North America, A. donax was introduced into southern California in the early 1800s for erosion control with latter introductions being made in Texas and Florida as late as the 1940s (Bell, 1997; Perdue, 1958). Since its introduction, giant reed has been widely cultivated in North America and has escaped cultivation in some areas (Perdue, 1958).
Genetic diversity is important for the selection, cultivation, and potential breeding of A. donax with desirable traits including high biomass yields, resistance to pest and diseases, and regional adaptability. Unfortunately, a low level of genetic diversity has been reported for A. donax in southern North America and southern Europe (Ahmad et al., 2008; Hardion et al., 2012; Khudamrongsawat et al., 2004; Lewandowski et al., 2003; Mariani et al., 2010; Pilu et al., 2014). For example, the G:N ratio of unique genotypes (G = unique genotypes and N = samples) was 0.050 in France and 0.011 in the United States (Ahmad et al., 2008), and ranged from 0.083 to 0.093 in two studies in Italy (Mariani et al., 2010; Pilu et al., 2014). However, Khudamrongsawat et al. (2004) reported a G:N ratio of 0.41 indicating a more moderate level of genetic diversity in 97 accessions collected from eight populations along the Santa Ana River in southern California. The low level of genetic diversity for A. donax in Europe and the United States has been attributed to its lack of sexual reproduction and limited diversity in founding introductions. Reproduction of A. donax is almost exclusively asexual by clonal spread by rhizome extension and by aquatic dispersal of rhizomes and stem fragments (Johnson et al., 2006; Mariani et al., 2010; Perdue, 1958). A. donax has shown a very limited capacity to produce viable seed attributed to early gamtetophytic failure (Hardion et al., 2015).
Despite the relative lack of genetic diversity within A. donax, Cosentino et al. (2006) reported significant levels of variation in biomass yield among accessions in field trials in southern Italy. For example, the aboveground 2nd year biomass yield of clones from 39 different populations ranged from 14.9 to 34.2 Mg·ha−1 per year of dry matter, with an average of 22.1 Mg·ha−1 per year. Expanding germplasm collections with accessions from other areas, particularly Asia, may capture greater genetic diversity.
The base chromosome number for Arundo has been reported as x = 6 or 12 (Hardion et al., 2011, 2013; Lewandowski et al., 2003). This confusion arises due to the high chromosome numbers resulting from multiple whole genome duplication events (Connor and Dawson, 1993, and discussed in Christopher and Abraham, 1971). However, Hardion et al. (2011, 2013, 2014) concluded x = 6 seemed to be the most suitable theoretical base number based on cytology of Arundinoideae and related taxa. Several cytotypes have been reported ranging from 2n = 12x (≈72) to 2n = 18x (≈108) (Bucci et al., 2013; Christopher and Abraham, 1971; Haddadchi et al., 2013).
Although there is limited genetic diversity within North American and southern European A. donax, there is evidence for substantial differences in yield between genotypes. Further, there has been no characterization of wild collected Arundo from South Asia. Thus, the objective of this study was to evaluate genetic diversity, cytogenetics (ploidy, chromosome numbers, and relative genome sizes) and biomass yields of Arundo taxa collected from North America and South Asia, to identify candidate genotypes for future development of North American bioenergy feedstocks.
Ahmad, R., Liow, P.S., Spencer, D. & Jasieniuk, M. 2008 Molecular evidence for a single genetic clone of invasive Arundo donax in the United States Aquat. Bot. 88 113 120
Angelini, L., Ceccarini, L., Nassi o Di Nasso, N. & Bonari, E. 2009 Comparison of Arundo donax L. and Miscanthus xgiganteus in a long-term field experiment in central Italy: Analysis of productive characteristics and energy balance Biomass Bioenergy 33 635 643
Barker, N.P., Linder, H.P. & Harley, E.H. 1999 Sequences of the grass-specific insert in the chloroplast rpoC2 gene elucidate generic relationships of the Arundinoideae (Poaceae) Syst. Bot. 23 327 350
Bell, G. 1997 Ecology and management of Arundo donax, and approaches to riparian habitat restoration in southern California, p. 103–113. In: J. Brock, M. Wade, P. Pysek, and D. Green (eds.). Plant invasions: Studies from North America and Europe. Backhuys Publishers, Leiden, The Netherlands
Bucci, A., Cassani, E., Landoni, M., Cantaluppi, E. & Pilu, R. 2013 Analysis of chromosome number and speculations on the origin of Arundo donax L. (giant reed) Cytol. Genet. 47 237 241
Chen, Z.J. 2007 Genetic and epigenetic mechanisms for gene expression and phenotypic variation in plant polyploids Annu. Rev. Plant Biol. 58 377 406
Christopher, I. & Abraham, A. 1971 Studies on the cytology and phylogeny of South Indian Bambusoideae, Oryzoideae, Arundinoideae, and Festucoideae Cytology 36 579 594
Cosentino, S., Copani, V., D’Agosta, G., Sanzone, E. & Mantineo, M. 2006 First results on evaluation of Arundo donax L. clones collected in southern Italy Ind. Crops Prod. 23 212 222
Don, R.H., Cox, P.T., Wainwright, B.J., Baker, K. & Mattick, J.S. 1991 ‘Touchdown’ PCR to circumvent spurious priming during gene amplification Nucleic Acids Res. 19 4008
Dudley, T. 2000 Arundo donax, p. 53–58. In: C. Bossard, J. Randall, and M. Hoshovsky (eds.). Invasive plants of Calfornia’s wildlands. Univ. of California Press, Berkeley, CA
Gilbert, R., Ferrell, J. & Helsel, Z. 2008 Production of giant reedgrass for biofuel. EDIS Publ. SS AGR 318. 1 May 2015. <http://edis.ifas.ufl.edu/ag327>
Haddadchi, A., Gross, C.L. & Fatemi, M. 2013 The expansion of sterile Arundo donax (Poaceae) in southeastern Australia is accompanied by genotypic variation Aquat. Bot. 104 153 161
Hardion, L., Verlaque, R., Baumel, A., Juin, M. & Vita, B. 2012 Revised systematics of Mediterranean Arundo (Poaceae) based on AFLP fingerprints and morphology Taxon 61 1217 1226
Hardion, L., Verlaque, R., Rosato, M., Rosellό, J.A. & Vila, B. 2015 Impact of polyploidy on fertility of Mediterranean Arundo L. (Poaceae) C. R. Biol. 338 298 306
Hardion, L., Verlaque, R., Saltonstall, K., Leriche, A. & Vita, B. 2014 Origin of the invasive Arundo donax (Poaceae): A trans-Asian expedition in herberia Ann. Bot. (Lond.) 114 455 462
Hecker, K.H. & Roux, K.H. 1996 High and low annealing temperatures increase both specificity and yield in touchdown and stepdown PCR Biotechniques 20 478 485
Kao, K.N. 1975 A nuclear staining method for protoplasts, p. 60–64. In: O.L. Gamborg and L.Z. Wetter (eds.). Plant tissue culture methods. Natl. Res. Council Canada, Prairie Regional Lab. Saskatoon, SK, Canada
Kering, M.K., Butler, T.J., Biermacher, J.T. & Guretzky, J.A. 2012 Biomass yield and nutrient removal rates of perennial grasses under nitrogen fertilization BioEnergy Res. 5 61 70
Khudamrongsawat, J., Tayyar, R. & Holt, J. 2004 Genetic diversity of giant reed (Arundo donax) in the Santa Ana River, California Weed Sci. 52 395 405
Les, D. & Philbrick, C. 1993 Studies of hybridization and chromosome number variation in aquatic angiosperms: Evolutionary implications Aquat. Bot. 44 181 228
Lewandowski, I., Scurlock, J., Lindvall, E. & Christou, M. 2003 The development and current status of perennial rhizomatous grasses as energy crops in the US and Europe Biomass Bioenergy 25 335 361
Mariani, C., Cabrini, R., Danin, A., Piffanelli, P., Fricano, A., Gomarasca, S., Dicandilo, M., Grassi, F. & Soave, C. 2010 Origin, diffusion and reproduction of the giant reed (Arundo donax L.): A promising weedy energy crop Ann. Appl. Biol. 157 191 202
National Oceanic and Atmospheric Administration 2010 1981-2010 Normals. 10 Mar. 2016. <http://www.ncdc.noaa.gov/cdo-web/datatools/normals>
Nei, M. & Li, W.H. 1979 Mathematical model for studying genetic variation in terms of restriction endocleases Proc. Natl. Acad. Sci. USA 76 5269 5273
Noyer, J.L., Causse, S., Tomekpe, K., Bouet, A. & Baurens, F.C. 2005 A new image of plantain diversity assessed by SSR, AFLP and MSAP markers Genetica 124 61 69
Osborn, T.C., Pires, J.C., Birchler, J.A., Auger, D.L., Chen, J.Z., Lee, H. & Comai, L. 2003 Understanding mechanisms of novel gene expression in polyploids Trends Genet. 19 141 147
Palmer, I.E., Gehl, R.J., Ranney, T.G., Touchell, D. & George, N. 2014 Biomass yield, nitrogen response, and nutrient uptake of perennial bioenergy grasses in North Carolina Biomass Bioenergy 63 218 228
Pilu, R., Cassani, E., Landoni, M., Badone, F.C., Passera, A., Cantaluppi, W., Corno, L. & Adani, F. 2014 Genetic characterization of an italian giant read (Arundo donax L.) clones collection: Exploiting clonal selection Euphytica 196 169 181
Polunin, O. & Huxley, A. 1987 Flowers of the Mediterranean. Hogarth Press, London, UK
Rohlf, F.J. 1989 NTSYS-PC numerical taxonomy and multivariate analysis system. Exeter, New York, NY
Schönswetter, P. & Tribsch, A. 2005 Vicariance and dispersal in the alpine perennial Bupleurum stellatum L. (Apiacese) Taxon 54 725 732
Thompson, J. & Lumaret, R. 1992 The evolutionary dynamics of polyploidy plants: Origins, establishment and persistence Trends Ecol. Evol. 7 302 307
Vollmer, K., Rainbolt, C. & Ferrel, J. 2008 Giant reed (Arundo donax): Biology, identification and management. EDIS Publication SS AGR 301. 1 May 2015. <http://edis.ifas.ufl.edu/ag307>