Genetic variability during in vitro establishment of bacurizeiro (Platonia insignis Mart.): an Amazon species
Tácila Rayene dos Santos Marinho, Thaís Roseli Corrêa, Karina da Silva Vieira, Irislene Souza Albuquerque, Givago Lopes Alves, Marcos Vinícius Marques Pinheiro, Fabrício de Oliveira Reis, Fábio Afonso Mazzei Moura de Assis Figueiredo, José Ribamar Gusmão Araújo, Tiago Massi Ferraz
Abstract
As a Brazilian Amazon fruit, bacuri tree (Platonia insignis Mart.) has been pointed out as an important species to the sustainable management and development of the Amazon region. However, since it is not yet domesticated, techniques regarding its propagation are still incipient. This study aimed to evaluate the genetic control of traits related to in vitro establishment of Platonia insignis accessions from different regions of the Maranhão state, Brazil. Immature fruits were collected over different sites for explants obtention. The in vitro responsiveness of the genotypes was evaluated by assessing the percentage of explant oxidation (OXI), pinkish-colored defense structures (PCDS), callogenesis (CAL), radicle (ROOT) and shoot forming (SHOOT). Callus was classified according to its callogenic potential, namely as: globular-friable, with higher embryogenic potential; undefined structure [cell mass], with lower embryogenic potential; and white spongy-like callus, absent of embryogenic potential. The estimates of genetic parameters were accomplished via REML (Restricted Maximum Likelihood)/BLUP (Best Unbiased Linear Prediction) mixed model. The outputs showed high genetic variability within the studied population. Additionally, accessions AC.7, AC.2, AC.1, AC.6, and AC.8 showed as more efficient by considering characteristics related to the in vitro regeneration, thereby presenting a superior callogenesis ability; lower susceptibility to oxidation; and higher capacity for root and shoot formation. This was the first study to investigate the relationship among genetic parameters and selecting accessions of P. insignis for in vitro regeneration, thus providing support for studies related to micropropagation and domestication of this species