Genetic diversity and structure of natural populations of Gossypium mustelinum, a wild relative of cotton, in the basin of the De Contas River in Bahia, Brazil.
Gossypium mustelinum is a wild cotton relative found only in the semiarid region of Bahia state in Brazil, and changes caused by humans in the natural habitat of this species have endangered the existence of several natural populations. Information about the occurrence and genetic composition of these populations is necessary to design effective conservation measures. The aim of this study was to characterize the in situ maintenance mode and assess the genetic diversity of G. mustelinum populations in the basin of the De Contas River. A sample of 205 G. mustelinum specimens was collected from the margins of the Jacaré, Riacho Quixaba, Riacho Serra Azul, and Riacho Riachão rivers and genotyped using 13 SSR primer pairs. In general, all G. mustelinum populations exhibit inadequate in situ maintenance, predominantly due to the deforestation of riparian vegetation and herbivory. The observed total genetic diversity of G. mustelinum was significant (H E = 0.489), highly structured (F ST = 0.534), and organized in homozygous genotypes (F IS = 0.873). The high observed inbreeding level is consistent with the predominance of self-fertilization and geitonogamy (t m = 0.234). In addition, the pattern of genetic structure tended to form groups that coincided with the collection sites, i.e., first clustering within subpopulations, then within populations, and finally within the closest populations. Thus, the observed genetic diversity is likely to be rapidly lost, and conservation measures should therefore be undertaken.
Instituto Federal Goiano, Km 2.5, Urutaí, Goiás, 75790-000, Brazil.
Ivandilson Pessoa Pinto
IP
de Menezes
Fernanda Amato
FA
Gaiotto
Lucia Vieira
LV
Hoffmann
Ana Yamaguishi
AY
Ciampi
Paulo Augusto Vianna
PA
Barroso
D001938:Brazil; D018744:DNA, Plant; D017753:Ecosystem; D005787:Gene Frequency; D040342:Genetic Structures; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D003368:Gossypium / Q000145:classification / Q000235:genetics*; D018895:Microsatellite Repeats; D010802:Phylogeny
D018744:DNA, Plant