Phylogeny of the Genus Noccaea (Brassicaceae) and a Critical Review of its Generic Circumscription

Abstract

Noccaea Moench is taxonomically one of the most problematic genera of the Brassicaceae. The radical revision of Thlaspi L. s.l. by Meyer in 1973 (Meyer, 1973) split it into 12 segregate genera, including Noccaea, but subsequent molecular studies suggested that this complex includes at least four unrelated genera (Thlaspi s. str., Mummenhoffia Esmailbegi & Al-Shehbaz, Noccidium F. K. Mey., and Noccaea). Although several taxonomic treatments have since been proposed to sort out the systematic problems of Noccaea, debates are still ongoing. Some authors have argued that all segregates of Thlaspi should be considered as independent but related genera, whereas others recognize them as synonyms of a large and polymorphic Noccaea. In this study, we present the first extensively sampled phylogenetic analysis of tribe Coluteocarpeae (Thlaspi segregates including Noccaea) using internal transcribed spacer (ITS) DNA sequences from 92 of the ca. 130 species (70%) in the tribe (39 studied here for the first time) and plastidic trnL-F regions from 73 species (42 studied here for the first time), representing the full range of morphological variation and geographical distribution. All main clades are discussed in detail, and the taxonomic status of all Thlaspi s.l. segregates is evaluated against recent taxonomic treatments. In particular, the tribal placement of Noccidium is changed to Coluteocarpeae, and the genus Pseudosempervivum (Boiss.) Grossh. is reduced to synonymy of Noccaea. The new name N. mummenhoffiana Özüdoğru & Al-Shehbaz and the new combinations N. aucheri (Boiss.) Özüdoğru & Al-Shehbaz and N. sempervivum (Boiss. & Balansa) Özüdoğru & Al-Shehbaz are proposed.

Structural characterization of ITS2 and CBC species concept applications in the tribe Coluteocarpeae (Brassicaceae)

“…On the basis of Torres-Suárez (2014) findings, only one CBC, between the outgroup and the tribe Coluteocarpeae, indicates that Noccaea sensu Al-Shehbaz (2014) was more acceptable despite of some studies (Ali et al, 2016a;2016b;Karaismailoğlu and Erol, 2018; https://brassibase.cos.uni-heidelberg.de/, accessed 27 August 2019) which disagree with generic delimitation of Al-Shehbaz (2014). This finding is also supported by previous studies (German, 2017;Özgişi, 2018a;Özgişi et al, 2018b;Güzel et al, 2018;Özüdoğru and German, 2018;Özüdoğru et al, 2019) which consider that Noccaea sensu Al-Shehbaz (2014) is more acceptable.…”

“…The internal transcribed spacers (ITSs) of ribosomal RNA have been frequently used molecular markers for the tribal and generic classification of the tribe Coluteocarpeae (Mummenhoff and Zunk, 1991;Mummenhoff et al, 1997b;Koch and Al-Shehbaz, 2004;Warwick, 2010;Özüdoğru et al, 2019). Furthermore, ITSs are the most commonly used (Doğan et al, 2011;Mutlu, 2018;Özgişi, 2020) nuclear markers for estimating phylogenetic relationships among the rest of the family due to their ubiquitous presence, sufficient synapomorphic characters, and costeffectiveness.…”

Characterization of Its1 Secondary Structure in Ten Species of Coluteocarpeae (Brassicaceae) and Its Taxonomical Utility

“…Al-Shehbaz [19] suggested an expanded Noccaea concept and treated all of the species and segregates under the generic name Noccaea with the exception Thlaspi s.str and Noccidium. Although phylogenetic studies of Özüdoğru et al [20] supports generic delimitation of Al-Shehbaz [19], some authors [17,18] have chosen to follow different concepts.…”

“…In present, It is aimed to characterize the ITS1 secondary structure of representatives of the tribe Coluteocarpeae (Brassicaceae).Tribe Coluteocarpeae is a member of Expanded Lineage II which is one of the four main Brassicaceae lineages (Aethionemeae, I, expanded II, and III). According to some authors [15,16,17,18], tribe consists of many different genera whereas some [19,20] indicate that these genera should be assigned under genus Noccaea Moench. The members of the genus were treated within the genus Thlaspi L. until the studies of Meyer [15,16] who divided Thlaspi into 12 segregate genera.…”

Comparative anatomy and pollen morphology of two endemic Noccaea species (Brassicaceae) and their taxonomic significance

“…Brassicaceae is a large angiosperm family of plant kingdom, represented by a total of 348 genera and 4065 species distributed worldwide in all continents except for Antarctica (Appel and Al-Shehbaz, 2003;Al-Shehbaz et al, 2006;Özüdoğru et al, 2019). It is primarily concentrated in temperate regions, particularly the Mediterranean basin and southwest and central Asia (Kandemir et al, 2017).…”