Historical herbarium specimens in plant molecular systematics — an example from the fern genus Lindsaea (Lindsaeaceae)

Abstract

We extracted, amplified and sequenced DNA from historical herbarium specimens and silica-dried samples of the fern genus Lindsaea in order to study the sequencing success between the two kinds of samples. High quality sequences were obtained from 57% of the herbarium samples. The specimens age was found to be of little importance for sequencing success when less than 75 years, but the colour of a specimen was found more indicative of sequencing success. Shorter DNA fragments were sequenced successfully twice as often as longer fragments from the herbarium material; in relatively recently collected silica-dried material longer sequences were obtained almost as frequently as short ones. No obvious differences in sequencing success between material originating from different herbaria was observed. We conclude that by using specifically designed DNA extraction protocols and by sequencing short DNA fragments from carefully selected specimens, herbarium material and type specimens can be successfully used in molecular systematics. Typical material or specimens from the type locality (topotypes) should be preferred, when placing a species in a phylogeny.

Phylogenetics and classification of the pantropical fern family Lindsaeaceae

“…We obtained silica‐dried material for 37 specimens and used herbarium material to broaden the molecular sampling by another 158 specimens. Because DNA fragmentation is a problem with herbarium material, we had to focus on relatively short sequences (Lehtonen & Christenhusz, 2010). This precluded using the conservative mitochondrial genome (Seberg & Petersen, 2006) and many of the plastid markers commonly used in fern systematics (e.g.…”

Testing the viability of seeds from old herbarium specimens for conservation purposes

“…In addition to the information contained in herbarium vouchers, the plant material itself may also be useful to many studies. Herbaria are indeed reservoirs of morphological and chemical data, active enzyme and DNA material (e.g., Andreasen & al., 2009;Lehtonen & Christenhusz, 2010), but also repositories of live seeds or spores with great biosystematics potential (Windham & Haufler, 1986). Given the current endangerment and accelerated loss of vascular plant species, plant collections in herbaria are a valuable seed resource for conservation and recovery of a potentially vast array of living plant species (Bowles & al., 1993).…”

The effects of sample age and taxonomic origin on the success rate of DNA barcoding when using herbarium material

“…Herbarium samples are commonly used for studies on molecular systematics or for the generation of DNA barcoding libraries. For instance, Lehtonen and Christenhusz (2010) have used historical herbarium specimens to study the molecular systematics of the fern genus Lindsaea using two chloroplast loci (trnL-trnF and trnS GGA -rps4). The age of the samples ranged from 4 to 172 years, and the total success rate was 57%.…”

“…For plant barcoding, herbarium collections are a major source of materials. It has been well documented that DNA is often well preserved in herbarium samples and, therefore, can be used for DNA analyses, such as sequencing in molecular systematic and phylogenetic studies, and DNA barcoding (e.g., Lehtonen and Christenhusz 2010;von Cräutlein et al 2011;Xu et a. 2015;Kuzmina et al 2017).…”