The so-called primitive genera of Genisteae (Fabaceae): systematic and phyletic considerations based on karyological data

Abstract

A karyological analysis of the so-called primitive genera of Genisteae has shown that they have a relatively homogeneous chromosome complement: all species tend to have a somatic chromosome number 2n = 48, which can increase to 2n = 52, presumably as a result of hyperaneuploidy. Karyological data suggest that Argyrocytisus, Cytisophyllum and Petteria may be considered as distinct genera rather than being assigned to Cytisus, with 2n = 52 for the first of these and 2n = 50 for the other two genera. They may be interpreted as relict monotypic genera as a result of the presence of a stabilized aneuploidy. Karyological characters exclude a recent origin of Genisteae from Thermopsideae. On the contrary, they are consistent with the hypothesis that Genisteae and Thermopsideae are independently derived from a basic papilionoid stock, of which present day Sophoreae are the remainder. At least two lines would lead from Sophoreae to the taxa of the 'genistoid alliance', one to Thermopsideae and the other 'podalyrioid alliances' (Podalyrieae and Mirbelieae), with the prevailing basic number of x = 9, and the other to Genisteae, with a basic number of x = 12 persisting in some present day genera, including Cytisus s.l. From this lineage, a wide range of secondary basic numbers has been formed, mostly by descending aneuploidy.

Joseph Dalton Hooker (1817-1911) - a great Linnean

“…Publications in recent issues of the Botanical Journal of the Linnean Society contain many references to the publications of Hooker. These include articles relating to the angiosperm families Apiaceae (Degtjareva et al ., 2009), Bromeliaceae (De Faria, Wendt & Brown, 2010), Combretaceae (Maurin et al ., 2010), Commelinaceae (Cabezas et al ., 2009), Fabaceae (Cusma‐Velari & Feoli‐Chiapella, 2009; Lackey, 2009), Gunneraceae (González & Bello, 2009), Hydrangeaceae (Liu & Zhu, 2011), Lamiaceae (Bramley, 2009; Wang & Hong, 2011), Liliaceae (Wang et al ., 2009), Linaceae (Simbaña & Tye, 2009; McDill & Simpson, 2011), Melastomataceae (Reginato, Michelangeli & Goldenberg, 2010), Nepenthaceae (Chase et al ., 2009), Orchidaceae (Micheneau et al ., 2009; Pupulin, 2010; Adams, 2011), Poaceae (Sun et al ., 2010), Ranunculaceae (Ehrendorfer et al ., 2009), Rosaceae (Chin et al ., 2010) and Sarraceniaceae (Chase et al ., 2009), gymnosperms (Gnetales; Rydin, Khodabandeh & Endress, 2010) and bryophytes (Wilbraham, 2010). The number and wide taxonomic coverage of these articles clearly demonstrate the ongoing significance of his scientific legacy.…”

Estudos citogenéticos e taxonômicos em espécies brasileiras de Swartzia Schreb. (Leguminosae-Papilionoideae)

“…Polyploidy has been related to several Leguminosae groups (Biondo et al 2005a;Cusma-Velari & Feoli-Chiapella 2009;Santos et al 2012) and has been an important undergone process in the evolutionary history of the family Soltis et al 2009). Allopolyploidy and autopolyploidy are both mechanisms of polyploidization (Stebbins 1971;Leitch & Bennet 1997;Soltis et al 2007) and have been issue of taxonomical discussions (Lewis 1980;Soltis et al 2007).…”