Stomatal size, ploidy and polyembryony in Eriotheca Stellate Trichome Species Complex (Bombacoideae - Malvaceae) in the Cerrados of Brazil.
Plant Biol (Stuttg)
; 23(1): 91-99, 2021 Jan.
Article
em En
| MEDLINE
| ID: mdl-32853431
Geographic parthenogenesis, range expansion of apomictic plants after climate changes, has been described for Northern Hemisphere gametophytic apomicts. But similar trends have been observed for sporophytic apomicts of Cerrado, the savannas in Brazil. Eriotheca pubescens is a common Cerrado tree, an agamic complex of either hexaploid/polyembryonic apomicts or tetraploid/monoembryonic sexual individuals. Some populations have been described as a new species, Eriotheca estevesiae, all included in the Eriotheca Stellate Trichome Species Complex (ESTSC). Since breeding systems and ploidy are clearly associated with polyembryony and stomatal size, we used these ancillary features to map the reproductive and ploidy level traits of E. pubescens and E. estevesiae. Leaves and seeds were collected from individuals of 19 populations. Seeds were evaluated for the presence of polyembryony and leaves for stomatal measurements. Eight populations were monoembryonic while another eight were polyembryonic and for other three, the embryonic pattern was not readily verified. E. pubescens polyembryonic and hexaploid populations formed a homogeneous group, but monoembryonic plants were more variable. E. estevesiae populations were monoembryonic with smaller stomata. In contrast, some E. pubescens monoembryonic populations further south presented larger stomata. Despite these outliers, possibly mixed populations, stomatal size and embryonic pattern differed from northern to southern populations. Embryonic pattern and stomatal size indicated that northernmost populations of Eriotheca STSC (E. estevesiae) are diploid and sexual. Southernmost populations, mostly polyembryonic and with large stomata, are hexaploid and apomictic. This is in agreement with geographic parthenogenesis and range expansion of apomictic lineages to southern habitats available after the last glacial maximum.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ploidias
/
Malvaceae
/
Estômatos de Plantas
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Plant Biol (Stuttg)
Assunto da revista:
BOTANICA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido