Challenges and Opportunities for in situ Maintenance of the Native Brazilian Cotton Gossypium mustelinum Miers

The native Brazilian cotton Gossypium mustelinum has never been planted. It is tetraploid and may cross with cultivated cotton. Endemic to Northeast Brazil, it was known only to grow in semi-arid areas, but expeditions in 2011, 2016, and 2018 localized plants in preservation areas on the coast of Northeast Brazil (in the States of Paraiba and Pernambuco), as predicted before by niche simulations. New climatic modeling shows that new populations can still be found in the Pernambuco semi-arid area, despite the lack of herbarium and germplasm bank information. Historical data show that the preserved populations are in regions where sympatry has not occurred in the last 47 years. Gene flow is unlikely to be a threat, and communication may foster significantly in in situ preservation.

Evaluation of Genetic Diversity by Molecular Markers ISSR of Algodoeiro (Gossypium mustelinum) in Native Populations of Pernambuco, Brazil

In order to assure and evaluate the genetic diversity, wild populations of Cotton (Gossypium mustelinum) were collected and evaluated from the coastal plain north of Pernambuco, Brazil. Such populations occur in urban areas in a state of real expansion and with imminent risks of extinction. As a result of these risks and the state of real expansion, aiming at the ex situ conservation of these genetic resources, branches of 66 plants were collected in three populations of G. mustelinum that are located in restinga vegetation in the localities of Ponta de Pedras and Bara of Catuama, both in the municipality of Goiana and in the locality Sossego Beach in the municipality Island of Itamaracá. The collected genotypes were inserted in a new Germplasm Bank (BAG) at the Federal Rural University of Pernambuco, after which a sample composed of 24 genotypes contained in the BAG was collected to perform genetic diversity studies using molecular markers of ISSR type. For the molecular analysis, 24 accesses with 4 ISSR primers were analyzed, which produced a total of 36 bands, with a mean of 1,52 alleles per amplified locus. The genetic dissimilarity values, calculated according to the complement of the Jaccard index, ranged from 0.000 to 0.080. The UPGMA method grouped the accesses into three groups. The UFRPE30, UFRPE42 and UFRPE45 accessions were more dissimilar and UFRPE-48, UFRPE-50, UFRPE-52, UFRPE-55, UFRPE60, UFRPE06, UFRPE28, UFRPE29, UFRPE1, UFRPE2, UFRPE17 the least dissimilar. The ISSR markers used in this study demonstrated efficiency in the detection of molecular polymorphisms, revealing genetic variability among the 24 accessions. Considering the results obtained in this work, it is possible to infer that there is considerable genetic variability among the accessions of cotton, demonstrating the importance of the markers in the analysis of variability of species not studied, such as (G. mustelinum).