Research Article The genetic diversity and population structure of <i>Genipa Americana</i> (Rubiaceae) in Northern Mato Grosso, Brazil

Abstract

Genipa americana (Rubiaceae) is an endemic Amazon-region species that may be subject to inbreeding, since it grows in fragmented environments. To examine this possibility, we examined the genetic diversity and population structure of three G. americana populations naturally grown in Northern Mato Grosso State using SSR markers. Sixty-four individuals were sampled from the three populations: 20 in AFL, 20 in MTP, and 24 in NBD. DNA extraction was performed according to the CTAB method, with modifications. Six SSR primers developed for the species were used. The allele frequency, the observed and expected heterozygosity, polymorphism information content), and the fixation Index were estimated. Molecular variance and principal coordinates analyses were conducted, and the most likely number of groups was inferred using the Structure software to help understand the genetic structure of the populations. The six microsatellite loci used showed 17 alleles, ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 17 (4): gmr18017 D.A.C. Ruzza et al 2 in total, ranging from 2 to 4 alleles per locus, with a mean of 2.83. The expected heterozygosity ranged from 0.35 to 0.67 and remained higher than the observed heterozygosity for all loci. The three populations showed genetic diversity, shared genetic material and presented high inbreeding indexes. Cluster analysis results showed genetic material sharing between populations, as well as a lack of genetic structuring among individuals according to their geographical origins. The molecular characterization revealed that the genetic diversity is higher within than between populations. The three populations had shared genetic material and a high inbreeding index due to low observed heterozygosity. This could be a consequence of the fragmented environment where these populations currently live in, since it reduces the number of G. americana individuals and can increase inbreeding.

Research Article Genetic diversity in native <i>Genipa</i> <i>americana</i> (Rubiaceae) populations in Sergipe, Brazil

“…It belongs to the Rubiaceae family, with cosmopolitan distribution concentrated in the tropics, including approximately 550 genera and 9,000 species. In Brazil, there are about 120 genera and 1,400 species, corresponding to the most populous family of the Cerrado biome and it is an important element in almost all natural formations (Souza and Lorenzi, 2012;Ruzza et al, 2018).…”

Estimating genetic diversity, mating system and pollen dispersal to inform ex situ conservation of the tree Genipa americana L.

“…(2017) studying adults, juveniles and open-pollinated seeds from two reproductive events found a lower mean observed ( H o = 0.38–0.54) and expected heterozygosity ( H e = 0.55–0.77). Another study on three G. americana populations in the Amazon forest using six simple sequence repeat loci (Ruzza et al ., 2018), three of which were the same as those used herein, also reported lower H o (0.13–0.21) and H e (0.48–0.57) than our study. The differences between studies may be due to the sample size and natural history of the studied populations (bottleneck and founder effects).…”

Microsatellites are important for forest genetic resources conservation in Brazilian biomes

“…The analysis of the genetic diversity and population structure of three Genipa americana populations revealed 17 alleles, the expected heterozygosity ranged from 0.35 to 0.67 and remained higher than the observed heterozygosity. The populations presented high inbreeding (F IS = 0.40), probably because of fragmentation (Ruzza et al 2018).…”