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Karyotype analysis and chromosome evolution in South American species of Lathyrus (Leguminosae)
Author(s) -
Seijo J. Guillermo,
Fernández Aveliano
Publication year - 2003
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.90.7.980
Subject(s) - biology , lathyrus , karyotype , chromosome , chromosome number , botany , evolutionary biology , chromosome morphology , genetics , zoology , gene
The karyotypes of 10 species and one variety of South American Lathyrus were determined and compared with those obtained of five entities from the Northern Hemisphere. Although all the species have a chromosome number of 2 n = 14, they could be differentiated by their karyotype formula and quantitative parameters of the karyotypes. Phenetic distance and principal component analysis showed that in spite of the differences observed among entities, they can be grouped in clusters that coincide with the taxonomic sections established by F. K. Kupicha and with the life cycle of the species. South American species form a homogeneous group and can be distinguished by the presence of a subtelocentric pair, which has a macrosatellite in the long arm, and the lack of a short metacentric pair characteristic of most species of the Northern Hemisphere. From an evolutionary point of view, variation in total chromosome length without major changes in the karyotype formula suggests that changes in the amounts of genomic DNA are proportional to the relative length of each chromosome arm and that species of Notolathyrus evolved in a concerted fashion. Variation in genome size, however, is congruent with morphological variation of some reproductive organs as well as with the life cycle and minimum generation time, as predicted by the nucleotype hypothesis.