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Polygalaceae kozmopolit bir yayılıma sahip, 27 cins içinde yaklaşık 1,200 türe sahip geniş bir familyadır. Ancak, birçok bitki grubu gibi, Polygalaceae türlerinin tanımlanması genellikle çiçek ve meyva karakterlerine bağlıdır, ki bu nedenle DNA barkodlama steril materyalin doğru tanımlanmasını sağlayabilir. Bu çalışmada altı tane yaygın olarak kullanılan DNA barkodu, rbçL, matK, trnL-F DNA bölgesi (trnL intron+trnL-F intergenic spacer dahil), tüm ITS (ITS1+5.8S+ITS2), subunits ITS1 and ITS2 DNA bölgelerinin, Maximum Likelihood (ML) ve TAXONDNA yöntemleri kullanılarak DNA barkodu olarak performansları değerlendirilmiştir. Sonuçlar göstermiştir ki, altı DNA bölgesinden hiçbiri ideal değildir, ancak Polygalaceae familyası için en uygun DNA barkodu matK gen bölgesidir., Polygalaceae is a large family with a cosmopolitan distribution, comprising ca. 1,200 species in 27 genera. However, similar to many plant groups, the identification of Polygalaceae species mostly depends on floral and fruit characteristics; therefore, DNA barcoding could easily warrant the corect identification of sterile material. In the current study, the utility of six widely employed plant DNA barcode loci, namely rbcL, matK, trnL-F region (including trnL intron+trnL-F intergenic spacer), the entire ITS (ITS1+5.8S+ITS2) as well as subunits ITS1 and ITS2 have been explored by performing Maximum Likelihood (ML) and TaxonDNA analyses. The results have shown that, while none of the six loci reviewed here completely fulfils the ideal DNA barcoding criteria; yet, matK region is the most useful DNA barcode for Polygalaceae.

Fabales is a cosmopolitan angiosperm order that consists of four families: Leguminosae (Fabaceae), Polygalaceae, Surianaceae, and Quillajaceae. Despite the great interest in this group, a convincing phylogeny of the order is still not available. Therefore, the aim of this study was to explicitly test for possible long branch attraction (LBA) problems within Fabales for the first time, and determine whether low tree stemminess and unequal branch lengths could worsen this problem. Supermatrix analysis of Fabales was carried out using previously published plastid matK, trnL, rbcL, and newly sequenced nuclear sqd1 regions for 678 taxa in total, including 43 outgroup taxa from families of Fabidae. We employed additional analyses, such as simulations, network analyses, sampling different outgroup taxa (random or real), removing fast evolving sites and fast evolving taxa, and molecular clock rooting, to identify both LBA and (or) rooting problems. These analyses clearly show that the Fabales phylogeny has been influenced by the sampling of outgroup taxa, but not LBA. However, network analyses show that even though it is weak, there is a consistent phylogenetic signal among the rapidly radiated Fabales families, which can be traced by further analyses. While, molecular clock rooting analysis yielded a (Leguminosae(Polygalaceae(Surianaceae+Quillajaceae))) topology with strong support for the first time here, supermatrix analyses yielded a ((Leguminosae+Polygalaceae)(Surianaceae+Quillajaceae)) with low-moderate support. © 2020, Canadian Science Publishing. All rights reserved.

Leguminosae, Polygalaceae, Quillajaceae and Surianaceae together comprise the order Fabales. Phylogenetic relationships within Fabales remain an unsolved problem even though interfamilial relationships have been examined in a number of studies using different sampling approaches and both molecular and morphological data. In this study, we gather information from the nuclear 26S rDNA region as well as previously published data from the sqd1,matK and rbcL regions. Phylogenetic analyses were performed by maximum parsimony, maximum likelihood and Bayesian inference. Overall, the best-supported topology for the relationships among families within the order places the pair of Leguminosae and Polygalaceae as sister to the pair of Quillajaceae and Surianaceae. However, our approximately unbiased (AU) test of the combined data results has shown that none of the seven different topologies rejected. Furthermore, three topologies were not significantly different from each other. Therefore, similar to the previous studies, this study did not find well-supported dichotomous relationships among the four Fabales families. The Fabales topology was very sensitive to both data choice and the phylogenetic methods used, which may indicate a rapid-near-simultaneous evolution of the four Fabales families. Our results also show that while nuclear sqd1 can be helpful as a complementary region, both the nuclear sqd1 and rDNA 26S regions could be problematic when analyzed individually. © 2020, Springer-Verlag GmbH Austria, part of Springer Nature.