Research Article

Intraspecific and interspecific polyploidy of Brazilian species of the genus Inga (Leguminosae: Mimosoideae)

Published: April 29, 2014
Genet. Mol. Res. 13 (2) : 3395-3403 DOI: https://doi.org/10.4238/2014.April.29.18
Cite this Article:
(2014). Intraspecific and interspecific polyploidy of Brazilian species of the genus Inga (Leguminosae: Mimosoideae). Genet. Mol. Res. 13(2): gmr2423. https://doi.org/10.4238/2014.April.29.18
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Abstract

We investigated the karyotypes of 13 species of six sections of the genus Inga (Leguminosae-Mimosoideae) from Brazil. We used conventional Giemsa staining to identify numerical chromosomal variations and looked for karyotypic evolutionary patterns. The karyotypes generally had small chromosomes, varying from metacentric to submetacentric, with a basic number x = 13. Nine of the species showed 2n = 2x = 26 (I. thibaudiana, I. cayennensis, I. ingoides, I. edulis, I. vera, I. subnuda, I. striata, I. bollandii, and Inga sp), while 2n = 4x = 52 was seen in a population of Inga cylindrical and of I. capitata, and in five populations of I. laurina. Additionally, 2n = 8x = 104 was observed in a population of I. cayennensis. Eight of these counts were new, while the counts of 2n = 52 for I. laurina and 2n = 26 for I. marginata, I. vera, I. subnuda, and I. edulis confirmed previous studies. We did not find cytological stability among the sections studied, with occurrence of significant intra- and inter-specific numerical variations. We conclude that polyploidy has played a significant role in karyotypic evolution in this group and that it occurred independently in several sections of the genus.

We investigated the karyotypes of 13 species of six sections of the genus Inga (Leguminosae-Mimosoideae) from Brazil. We used conventional Giemsa staining to identify numerical chromosomal variations and looked for karyotypic evolutionary patterns. The karyotypes generally had small chromosomes, varying from metacentric to submetacentric, with a basic number x = 13. Nine of the species showed 2n = 2x = 26 (I. thibaudiana, I. cayennensis, I. ingoides, I. edulis, I. vera, I. subnuda, I. striata, I. bollandii, and Inga sp), while 2n = 4x = 52 was seen in a population of Inga cylindrical and of I. capitata, and in five populations of I. laurina. Additionally, 2n = 8x = 104 was observed in a population of I. cayennensis. Eight of these counts were new, while the counts of 2n = 52 for I. laurina and 2n = 26 for I. marginata, I. vera, I. subnuda, and I. edulis confirmed previous studies. We did not find cytological stability among the sections studied, with occurrence of significant intra- and inter-specific numerical variations. We conclude that polyploidy has played a significant role in karyotypic evolution in this group and that it occurred independently in several sections of the genus.