Karyotypic studies in Solanum section Lasiocarpa (Solanaceae)

Abstract

Mitotic chromosomes of 13 species included in Solanum sect. Lasiocarpa were studied. All species have 2n = 24. The chromosome numbers of S. stagnale, S. felinum, and S. repandum are reported for the first time. Statistical analyses of chromosomes, genome length, and centromere position yielded estimates of karyotype composition and asymmetry. A generalized karyotype of the section shows that most of the chromosomes are metacentric (73%) or submetacentric (25.6%). Two pairs of subtelocentric chromosomes are present only in S. sessiliflorum. Satellites are quite common, characterizing chromosomes for ten species and are attached to the short arms of either m or sm chromosomes. They could be seen in 10% to 70% of the cells. Only S. pseudolulo bears two satellited chromosomes, one of them attached to a long chromosome arm. Although the section is chromosomally quite homogeneous, species can be distinguished by karyotype formula, presence of satellites in a particular chromosome pair, and total chromosome length. There are no indications of major chromosomal rearrangements within the section. Using cytological data exclusively, cluster analysis indicates S. sessiliflorum is isolated in the section. Solanum candidum and S. vestissimum are somewhat isolated as well and have unique karyological traits. Solanum pectinatum has a peculiar karyotype, but in the phenogram it is not particularly separated. Karyotype features suggest that morphological differentiation was not always followed by chromosomal divergence. The origin of the domesticated S. quitoense is no further elucidated by our data.

Karyotype Studies in Lycium Sections Schistocalyx and Sclerocarpellum (Solanaceae)

“…As reported for Solanum L. and other Solanaceae (Stebbins, 1971;Moscone, 1989a,b;Bernardello & Anderson, 1990;Bernardello et al, 1994), the Lycium karyotypes examined are constant and symmetrical. The existence of one satellited chromosome pair is common in the family (Moscone, 1989a), usually in the shorter arms of m pairs.…”

“…The existence of one satellited chromosome pair is common in the family (Moscone, 1989a), usually in the shorter arms of m pairs. At the same time, m and sm chromosomes are very frequent (Moscone, 1989a(Moscone, ,b, 1990Bernardello & Anderson, 1990;Bernardello et al, 1994).…”

Karyotype, Heterochromatin, and Physical Mapping of 5S and 18-5.8-26S rDNA Genes in Setiechinopsis (Cactaceae), an Argentine Endemic Genus

“…(Das and Mohanty 2006;). Thus, karyotypic features suggest that morphological differentiation in cacti was not followed by chromosomal divergence, as reported in other plant families (e.g., Bernardello et al 1994;Cox et al 1998;Acosta et al 2005;Chiarini and Bernardello 2006).…”

Karyological studies in Jaborosa (Solanaceae)

“…Within the many genera of Solanaceae studied to date, the number of satellited chromosome pairs is variable between the species of a single genus. For instance, in the subfamily Solanoideae, species of Capsicum may show one to four satellited chromosome pairs (Moscone, 1990, 1999; Moscone et al ., 1995) and species of Hyoscyamus may have one to three pairs (Sheidai et al ., 1999), whereas many Solanum species show just one pair (Bernardello, Heiser & Piazzano, 1994; Acosta et al ., 2005). By contrast, species of Lycium always show one satellited chromosome pair (Stiefkens & Bernardello, 1996, 2000, 2002, 2006).…”

“…By contrast, Jaborosa species present subtelocentric chromosomes, which are relatively unusual in the Solanaceae (for example, Bernardello & Anderson, 1990; Acosta & Moscone, 2000). Indeed, some Nicotiana species, from the subfamily Cestroideae, are unique in having a karyotype composed mostly of subtelocentric chromosomes (Goodspeed, 1954; Villa, 1984), and, in the subfamily Solanoideae, karyotypes with at least one subtelocentric pair have been described for only a few species of Hyoscyamus , Capsicum , and Solanum (Moscone, 1990, 1999; Bernardello et al ., 1994; Sheidai et al ., 1999; Acosta et al ., 2005). In a general survey of the family Solanaceae, Badr et al .…”