Caracterização de microssatélites e desenvolvimento de marcadores SSR em khaya grandifoliola C. DC

• Autor(a) principal: Sousa, Rodrigo Carlos Batista de
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10691
• topic: Clone; Microssatélite; Diversidade genética; Genotipagem; Microsatellite; Genetic diversity; Genotyping; CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

African mahogany (Khaya spp.) cultivation attracts increasing interest from producers, since their wood has similar characteristics to those of Brazilian mahogany with high commercial value in the European market. Despite its timber value throughout the world and its ecological importance in Africa, where it is classified as vulnerable to extinction, little is known about the species' levels of genetic diversity. Thus, this work aims to identify and characterize microsatellite regions in the transcriptome of Khaya grandifoliola, as well as to develop markers for studies of the genetic variability of the species. From the transcripts developed by Soares et al., (2019), microsatellite regions were identified and PCR primers were designed. Microsatellite sequences were classified according to the type and number of repetitions, as well as their location within transcripts. Using the microsatellite loci genetic parameters were estimated, such as the number of alleles per loci (K), expected and observed heterozygosity (He and Ho), intrapopulational fixation index (f), probability of exclusion of paternity and of identity (PE and PI). Within the African Mahogany transcripts, 37,925 microsatellite regions were detected, with 54% being mononucleotides, 29% dinucleotides and 15% trinucleotides. From 40 microsatellite loci, 12 were selected for labelling with fluorophores (6-FAM and HEX), forming two multiplex panels. The genotyping performed with the individuals identified an average of 3 alleles per locus. The expected (He = 0.53) and observed heterozygosity (Ho = 0.50) values used to estimate the genetic diversity in K. grandifoliola individuals were reasonable, given the low number of alleles per locus. The values found for PE (0.96) and PI (4.70x10-6) were similar to those found in studies of the same genus. Thus, these estimates indicate that the set of microsatellite markers is efficient in discriminating individuals. The SSR markers were also successfully transferred to other Khaya species. Therefore, these markers can be efficiently used in population studies with K. grandifoliola and other Khaya species.