Genetic diversity and DNA content of three South American and three Eurasiatic Trifolium species

Abstract

Six species of Trifolium (T. polymorphum Poir., T. riograndense Burkart, T. argentinense Speg., T. medium L., T. pratense L. and T. repens L.) were analyzed using inter-simple sequence repeats (ISSR) markers. Six selected primers generated 186 polymerase chain reaction (PCR) products exploring 112 loci in 34 genotypes analyzed with molecular sizes ranging from 200 to 1300 bp. These primers were able to discriminate among and within species, with the PCR products being on average 41.6% species-specific and 59.9% polymorphic at the within species level. Nuclear DNA content was determined by flow cytometry and revealed variation among species. The 1Cx genome size values were calculated and were found to range from 0.46 pg (T. pratense) to 0.96 pg (T. polymorphum). Genome size values of South American species were higher than those of Eurasiatic origin. The analyses of the molecular data grouped the six species in agreement with their geographical origin and clearly differentiate T. polymorphum from T. argentinense. The Eurasiatic group showed the highest average of species-specific bands (45.3%) and the South American group exhibited the highest amount of total bands (59.7). The highest level of intra-species polymorphisms was detected in T. argentinense (92.9%), followed by T. medium (89.5%).

Genetic divergence among cupuaçu accessions by multiscale bootstrap resampling

“…If this value is lower than a significance level α, for a certain cluster, there are signs that the individuals that compose the cluster are not similar. The multiscale bootstrap resampling technique was used in genetic diversity studies of Trifolium (Rizza et al, 2007) and of Nipponia nippon (Taniguchi et al, 2013), among others. This study aimed to analyze the genetic divergence of eighteen cupuaçu accessions through methods of cluster analysis, comparing the outcome obtained by the hierarchical UPGMA agglomerative method with and without the application of the multiscale bootstrap resampling technique and by the Tocher's optimization method.…”

Modern methods for genetic improvement of Trifolium pratense.

“…However, the ISSR-PCR method using primers based on di-, tri-, tetra-, and pentanucleotide repeats seems particularly suitable for germplasm comparison. The advantage is the better repeatability of the ISSR methodology compared to RAPD, as reported by Rizza et al (2007) for several species. The AFLP technique is a powerful and highly reliable tool capable of probing a large number of genomic loci per experiment and discriminating genetic differences.…”

“…Arumuganathan and Earle (1991) performed flow cytometric measurement and revealed 2C genome size of 0.97 pg. Rizza et al (2007) Sato et al (2005) deduced a haploid genome size of 440 Mb, as estimated by measuring the nuclear DNA content using flow cytometry (two red clover plants with 0.89 and 0.91 pg/2C), with 1 pg of DNA equivalent to 980 Mb (Bennett et al 2000). Ellison et al (2006) and Vižintin et al (2006) reported results of detailed and comprehensive studies of the molecular phylogenetic framework for the genus Trifolium.…”

Genetic diversity in quarin clover (T. quartinianum) accessions of Ethiopia using ISSR markers

“…A total of 13 ISSR primers obtained from Genetics Laboratory, Addis Ababa university (originally bought from University of British Columbia) were screened based on previously published results in Trifolium and related species for their ability to generate consistently amplified band patterns (Rizza et al, 2007;Dabkevičienė et al, 2011;Arslan and Tamkoc, 2009) and to access polymorphism in two samples for each population. Four primers were selected and used for the analysis of 24 accessions based on the number of amplification products, the quality of the profiles, the level of polymorphism and the reproducibility of bands (Table 2).…”

“…However, the Inter Simple Sequence Repeat (ISSR)-PCR method (Wolfe and Liston, 1998) using primers based on di, tri, tetra, penta nucleotide repeats without the requirement for prior knowledge of the genome sequence seems particularly suitable for germplasm comparison. For the Trifolium species studied, the ISSR markers were used for the first time to study genetic diversity of three South American and three Eurasiatic species (Rizza et al, 2007). ISSR markers were used to assess genetic diversity of four clover species from Europe (Dabkevičienė et al, 2011).…”