Genetic Diversity, Cytogenetics, and Biomass Yields among Taxa of Giant Reeds (Arundo Species)

Abstract

Genetic diversity and cytogenetics of 31 accessions of Arundo L., collected from North America and South Asia, were characterized using 20 intersimple sequence repeat (ISSR) markers, flow cytometry, and cytology. In addition, field trials of 23 Arundo donax L. accessions were established in 2011 and harvested in 2012 to 2013 to assess annual biomass yields. Cluster analysis, based on Jaccard’s similarity coefficient method, clearly differentiated Arundo formasana Hack. from A. donax and a third unidentified Arundo taxon. Arundo donax further contained two subgroups representing North American (naturalized and cultivated) and South Asian collections. Within each A. donax subgroup, genetic distances were very low (0.03 for North America and 0.07 for South Asia). Principle coordinate analysis further supported distinct clusters. Relative genome sizes were determined using Pisum sativum L. as the reference genome and 6-diamidino-2-phenylindole (DAPI) fluorochrome. Chromosome numbers (2n), ploidy levels, and 2C relative genome sizes ranged from ≈62 to 105, near 12x to near 18x, and 2.78 to 4.13 pg, respectively, and were similar within each taxa/subgroup. While there was a low level of genetic variability among A. donax accession, dry biomass yields varied significantly ranging from 6.5 to 65 Mg·ha−1 per year for the third growing season.