Gossypium mustelinum is the scientific name of a native wild cotton species in Brazil, which does not occur anywhere else in the world. In spite of not having economic importance, since its fibres are short, this cotton is of the same genus of cultivated cotton (Gossypium hirsutum) and can be genetically crossed with it, which makes it a species of great interest for scientific studies, as it is capable of contributing to the breeding of commercial plants. “The genetic traits of such native cotton are unique and can be a source for a study on resistance to pests and diseases”, explains the researcher from Embrapa Cotton (Campina Grande, PB) Lucia Hoffmann. According to the scientist, the plant could be a source of genetic material of interest for the breeding of the commercial species, thus its preservation is fundamental. With the aim of promoting the conservation of that species, the Embrapa researcher went on an expedition in the first fortnight of December, covering the towns of Lucena, Pitimbu (in the state of Paraíba - PB), Goiana, Itamaracá (in the state of Pernambuco - PE) and Macururé (in the state of Bahia - BA), where native cotton plants had been mapped. The species naturally occurs in the states of Bahia, Pernambuco and Paraíba, often close to the beds of non-perennial rivers and, when in the bush, it seems to have a preference for glades. According to Hoffmann, the work of monitoring native species in their natural ecosystems (in situ conservation) is performed with the aim of ensuring the highest genetic variability possible, and ensure the evolution of species in the course of time, according to environmental changes. In 2011, another expedition confirmed the existence of wild cotton populations in the coast of Paraíba and Pernambuco. “The plants also have some different characteristics from the ones that grow in Bahia and from the population that used to exist in Caicó, Rio Grande do Norte, which is extinct today. The main characteristics that were identified as different, besides their habitat, are the greater flower size and the absence of pronounced pilosity in leaves. During the expedition, efforts were focused towards making the in-situ maintenance of the plants viable”, informs Lucia Hoffmann. Besides observing the species development, the researchers also promote environmental awareness among the local population. “We talked to the owners of the place where the species is found so that they can become guardians of the plant in their region. Guardians should be able to recognize the species, and warn other people from their community about the existence of the native cotton in their properties and about the need to preserve this unique and typically Brazilian species”, she states. The researcher explains that the main threats to the conservation of the native cotton are, mainly, human interference (uprooting for diverse purposes), excessive cattle grazing, deforestation, and droughts. “As other vegetations in the Atlantic Rainforest, we have observed that the plants are often pulled out due to a lack of familiarity with the species”, she observes. Guardian action During the trip, Lucia Hoffmann found good and bad news. “In Macururé, the drought is very intense, hence the plants are very weak. But, to my surprise, the farmer Maria José, from São Francisco, had built a barbed wire fence protecting the plants on her own”, tells the researcher. The farmer recalls that in her property she once had large cotton shrubs, but the plants did not survive the droughts. “After the folks from Embrapa came, I bought the wire and had the cotton fenced so that the goats would not eat it, but after I fenced it, we had five years of drought, real drought, without rain”, Maria José recollects. “In another farm, the only one where there was cotton in Macururé, today only eight plants remain alive, thanks to macambira (Bromelia laciniosa). Because of the drought and the need for food, the cattle is released wherever there can be pasture, in the areas that remain moist such as the places where water accumulated, and the cattle likes to feed from the plant and the seed”, says Hoffmann. “In Itamaracá, one of the only two sets of plants previously located, which is in a plot of land right next to the beach, went through a forest fire. Four larger plants are closer to the beach, still have green leaves, and a higher number of plants still has seeds, which seem to be viable. I made contact with the State Environmental Agency (Santa Cruz Environmental Protection Area) to try to find and communicate to the landowners and their neighbors that the plants cannot be pulled out. The EPA has already been there to make the plant recognition.” In Lucena, next to the ruins of the Our Lady of Bonsucesso Church, there is a large number of plants. “It is difficult to say how many, as they are spaced out in the middle of the vegetation. There you can see that the cotton prefers glades. In our first visit in 2011, there were plants in the church, that must have been pulled out. In this visit, we noticed five small plants, on the church's side, that can be conserved.” Gene banks Gene banks or germplasm banks work as a reservoir of genes and are fundamental for research institutions that work with plant breeding. They are divided in active banks, in which the plants are kept alive in their natural conditions, and base banks, where plant parts (often seeds, but also pollen and other tissue) are conserved in cold chambers. To develop new crop varieties, breeding programs depend on the availability of genetic material that represent the genetic diversity of the species. Improved quality and productivity are the main traits researchers seek, but other factors such as lack of resistance to a given pest or disease, species adaptation to environmental changes, and new crop areas are also important. Embrapa has grown cotton plants that are endangered by droughts through seed multiplication, as was the case of the plants that were extinct in Rio Grande do Norte state. “We sowed the seeds and are waiting for them to bloom”, states Hoffmann. Seeds that had been harvested near two ponds in Macururé between 2003 and 2005 were also planted by Embrapa in Goiás, and germinated. “It will be important for maintenance that they blossom and produce seeds, since in Macururé, around those ponds, there are no cotton plants anymore”, she asserts. Translation: Mariana de Lima Medeiros