DArT-based characterisation of genetic diversity in a Miscanthus collection from Poland

Abstract

Analysis of 180 accessions of Miscanthus using a DArT platform revealed high diversity. The phylogenetic analysis revealed that M. × giganteus accessions fall into two genetically distinct groups. Miscanthus is a genus of perennial rhizomatous grasses that has emerged in last 20 years as a feedstock for bioenergy and biofuel production. Currently, the most widely used accession for bioenergy purposes is Miscanthus × giganteus, a sterile triploid hybrid between Miscanthus sinensis and Miscanthus sacchariflorus. However, previous reports have shown that genetic diversity of Miscanthus × giganteus is limited. Here, we report development of Diversity Arrays Technology platform for the analysis of genetic structure of a Miscanthus collection of 180 accessions. A total of 906 markers were obtained of which around 25.5% exhibited polymorphism information content value in the range of 0.40 and 0.50 and are considered particularly informative. Newly developed marker system will serve as an additional resource to assist crop improvement, germplasm preservation and genetic studies. Three types of analysis indicated that 180 accessions from the collection were well differentiated and presented high diversity. Interestingly, the analysis revealed that there are two separate groups of plants, significantly differing in genetic diversity, that are commercially available as M. × giganteus. We suggest that one of these groups is most likely mutants or somaclonal variants of original M. × giganteus. The other group is recent hybrids of Miscanthus of higher genetic diversity. This study indicates that the diversity of commercially available M. × giganteus is higher than commonly assumed. Development of the new marker system can significantly assist breeding of new commercial cultivars of Miscanthus for bioenergy use.

Miscanthus x giganteus crop fields hide a genotype of the invasive M. sacchariflorus

“…Tang et al . () did not use ITS sequencing to compare their samples to known accessions; however, we suspect that our two genotypes are the same pair of genotypes as found by Tang et al . ().…”

“…Also, the ITS sequence of Mxg produces a stronger nucleotide signal for the ITS allele of Msa due to the occurrence of two genome copies of Msa and only a single Msi in the triploid Mxg (2 n = 3 x ; Linde‐Laursen, ; Rayburn et al ., ). The occurrence of genotypic diversity among horticultural samples of Mxg has been observed previously in Poland via a microarray‐based genotyping method (Tang et al ., ). The authors also underlined that one of these two Mxg clusters was more related to some Msa samples than to the other Mxg cluster.…”

“…The hidden occurrence of Msa in the crop fields of Mxg in France and potentially Europe (Tang et al ., ) raises serious questions regarding its invasiveness (Schnitzler & Essl, ). As described previously, the abundant and aggressively spreading rhizomes of Msa were distinguishable from Mxg in fields.…”

“…( Mflo ) as mislabelled Msi accessions that correspond to Msa , or mislabelled Mflo that are closely related to the Mxg ‘Illiniois’ genotype (Oladeinde, ; Cichorz et al ., ). A pair of studies also found distinct genotypes in horticultural and experimental collections of Mxg (Chouvarine et al ., ; Tang et al ., ). This confusion in the taxonomic assignation of commercially sold Miscanthus accessions adds to the risk of introducing new and potentially invasive genotypes within European and North American crop fields.…”

“…In addition, current field research involving new hybrids also called Mxg could increase confusion regarding the genetic identity of cultivated accessions (Clark et al, 2018) (Oladeinde, 2012;Cichorz et al, 2014). A pair of studies also found distinct genotypes in horticultural and experimental collections of Mxg (Chouvarine et al, 2012;Tang et al, 2015). This confusion in the taxonomic assignation of commercially sold Miscanthus accessions adds to the risk of introducing new and potentially invasive genotypes within European and North American crop fields.…”