Genetic Diversity Among Paspalum L. Species (Poaceae) Belonging to the Notata and Linearia Groups Based on Restriction Fragment Length Polymorphism Analyses

Abstract

A taxonomic study of Paspalum L. was carried out using a genetic diversity approach. Thirty accessions representing twenty one different species from the Notata and Linearia groups of Paspalum were studied using restriction fragment length polymorphism analysis of the amplified ITS ribosomal DNA (rDNA) and from the psbA-trnH of the chloroplast genome (cpDNA). The combined analysis of the internal transcribed spacer (ITS) and the chloroplast spacer region between the psbA and trnH genes identified genetic polymorphisms. A distance analysis of the molecular data generated a dendrogram which showed the relationships of the two informal groups of Paspalum studied here. Although the distribution of species in the dendrogram was found to be roughly in agreement with previous works based on morphological and cytological data, the results obtained reveal the current artificiality in Paspalum taxonomy. Based on molecular data, a new circumscription of the Notata and Linearia groups is proposed here in order to provide a more accurate delimitation of these groups and contribute to the taxonomy of Paspalum. This study, although preliminary, reveals the potential utility of such a molecular approach for clarifying the taxonomy of closely related taxa.

Phylogeny of Linearia and Notata groups of Paspalum L. (Poaceae, Panicoideae, Paniceae) and related species

“…Observing the distribution of the informal groups in the tree, it can be seen that there is no monophyletic group corresponding to Notata, Linearia or both together, although a small part of Notata could be considered monophyletic, when it includes P. flaccidum. This behavior agrees with the work of Ferreira and Souza-Chies (2005), based on RFLP data, but not with the total evidence analysis including morphological data, which support the hypothesis of a single group formed by Linearia plus Notata together (Zuloaga et al 2004;Souza-Chies et al 2006). Excluding P. flaccidum, the seven other species are in fact very similar morphologically, so the clade maybe deserves some formal treatment.…”

Genetic diversity of the complex Paspalum notatum Flügge (Paniceae: Panicoideae)

“…However, the potential to detect polymorphism depends on the method used. Different molecular analyses were used among Paspalum species (Liu et al 1994;Pupilli et al 1997;Jarret et al 1998;Casa et al 2002;Ferreira and Souza-Chies 2005;Miz and Souza-Chies 2006).…”

Estudos genético-moleculares no gênero Paspalum L. (Poaceae: Panicoideae: Paniceae)

“…The reduced number of bands at some loci for the species genetically more distant from the species for which the primers were developed (Paspalum notatum and P. atratum) may be due to the presence of null alleles, i.e., mutations may have arisen in the region of primer annealing for some alleles. Non-amplifying or null alleles are not very common in the literature concerning plant species, but some examples have been observed (Souza et al, 2005); however, two facts emerge from human studies. First, these alleles are common;…”

“…Incluindo estudos taxonômicos 1996;Oliveira, 1996;2004;, citogenéticos Freitas et al, 1997;Adamowski et al, 2000;2003;Pozzobon et al, 2008;1997), genético-moleculares (Casa et al, 2002;Ferreira & Souza-Chies, 2005;Essis & Souza-Chies, 2006), agronômicos (Batista et al, 1987;1994;Batista & Godoy, 1998;Valentim et al, 2000), entre outros. Além disso, novas coletas têm sido feitas e vários acessos de Paspalum estão disponíveis na Faculdade de Agronomia (Universidade Federal do Rio Grande do Sul).…”