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Genetic relationships and polyploid origins in the Lippia alba complex
Author(s) -
Lopes Juliana M. L.,
Carvalho Humberto Henrique,
Zorzatto Cristiane,
Azevedo Ana Luisa S.,
Machado Marco Antonio,
Salimena Fátima Regina G.,
Grazul Richard M.,
Gitzendanner Matthew A.,
Soltis Douglas E.,
Soltis Pamela S.,
Viccini Lyderson F.
Publication year - 2020
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 - 10.1002/ajb2.1443
Subject(s) - biology , polyploid , lippia , ploidy , herbarium , botany , evolutionary biology , taxon , genetics , gene , essential oil
Premise Plant genomes vary in size and complexity due in part to polyploidization. Latitudinal analyses of polyploidy are biased toward floras of temperate regions, with much less research done in the tropics. Lippia alba has been described as a tropical polyploid complex with diploid, triploid, tetraploid, and hexaploid accessions. However, no data regarding relationships among the ploidal levels and their origins have been reported. Our goals are to clarify the relationships among accessions of Lippia alba and the origins of each ploidal level. Methods We investigated 98 samples representing all five geographical regions of Brazil and all ploidal levels using microsatellite ( SSR ) allelic variation and DNA sequences of ITS and trnL‐F . Nine morphological structures were analyzed from 33 herbarium samples, and the chemical compounds of 78 accessions were analyzed by GC – MS . Results Genetic distance analysis, the alignment block pattern, as well as RA x ML and Bayesian trees showed that accessions grouped by ploidal level. The triploids form a well‐defined group that originated from a single group of diploids. The tetraploids and hexaploid grouped together in SSR and trnL‐F analyses. The recovered groups agree with chemical data and morphology. Conclusions The accessions grouped by ploidal level. Only one origin of triploids from a single group of diploids was observed. The tetraploid origin is uncertain; however, it appears to have contributed to the origin of the hexaploid. This framework reveals linkages among the ploidal levels, providing new insights into the evolution of a polyploid complex of tropical plants.