Genetic diversity, mating system and reproductive phenology of Mimosa scabrella Benth: Implications for seed collection

Giulia Fabrin Scussel; Igor de Carvalho Aguiar Rodrigues; Ana Clara Alves Farias; Juliana Machado Ferreira; Francisco Ianzer Machado; Tiago Montagna; Maurício Sedrez dos Reis

doi:10.53661/1806-9088202650264045

Authors

Giulia Fabrin Scussel Federação das Associações de Apicultores e Meliponicultores de Santa Catarina, Florianópolis, Santa Catarina, Brasil https://orcid.org/0000-0002-5916-8890
Igor de Carvalho Aguiar Rodrigues Universidade Federal de Lavras, Programa de Pós-graduação em Engenharia Florestal, Lavras, Minas Gerais, Brasil https://orcid.org/0000-0003-2906-1432
Ana Clara Alves Farias Ministério do Desenvolvimento Agrário e Agricultura Familiar, Brasília, Distrito Federal, Brasil https://orcid.org/0009-0003-8236-3824
Juliana Machado Ferreira Universidade Federal de Santa Catarina, Programa de Pós-graduação em Recursos Genéticos Vegetais, Florianópolis, Santa Catarina, Brasil https://orcid.org/0000-0002-8590-8936
Francisco Ianzer Machado Universidade Federal de Santa Catarina, Mestre em Ciências, Florianópolis, Santa Catarina, Brasil https://orcid.org/0009-0003-5627-2507
Tiago Montagna Universidade Federal de Santa Catarina, Departamento de Fitotecnia, Florianópolis, Santa Catarina, Brasil https://orcid.org/0000-0002-7427-4237
Maurício Sedrez dos Reis Universidade Federal de Santa Catarina, Departamento de Agricultura, Biodiversidade e Florestas, Curitibanos, Santa Catarina, Brasil https://orcid.org/0000-0003-1331-3367

DOI:

https://doi.org/10.53661/1806-9088202650264045

Keywords:

Bracatinga, Outcrossing rate, Gene flow

Abstract

Ecological restoration requires seed sources of native species with sufficient genetic diversity to maintain the evolutionary potential of subsequent populations. Studies elucidating genetic variability, mating system, and reproductive phenology are crucial for designing seed collection strategies. These aspects were evaluated in two populations of Mimosa scabrella (Bom Retiro-BR and Urupema-URU, Santa Catarina) to support such strategies. Genetic variation was analyzed using nine isozyme systems in 50 adult trees per population. The same markers were employed in open pollinated progeny arrays, from both populations, to evaluate the mating system. Phenological observations were conducted for one year in 30 individuals per population. Genetic variation revealed high diversity (H_E= 0.190 in BR; 0.245 in URU), but significant fixation indexes (f= 0.237 in BR; 0.156 in URU). The species exhibited a mixed mating system, predominantly outcrossed (t_m= 0.852 in BR; 0.801 in URU), with selfing, biparental inbreeding, and correlated matings, resulting in high coancestry and low effective variance size. To retain an effective size of 100 individuals non-inbred and unrelated, it is recommended to collect seeds from at least 37 seed trees in BR and 39 in URU, spaced at distances higher than 50 m. Phenological patterns showed synchronized winter flowering and fruit dehiscence between February and March, delayed in URU by one month, and influenced by climatic variables. These results confirm both populations as valuable seed sources for restoration, with specific recommendations to maximize genetic representativeness and adaptive potential.

Keywords: Bracatinga, Outcrossing rate, Gene flow