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Researchers study characteristics and potential of native plants from Rio Grande do Sul

The study covers multiple areas such as production, spreading of seedlings and medical properties
Researchers study characteristics and potential of native plants from Rio Grande do Sul

Paulo Vitor Dutra de Souza coordinates dissemination of seedlings by means of clones – Gustavo Diehl/ UFRGS

Text: Camila Raposo

Studying the potential, characteristics,  and ranges of native plants from Rio Grande do Sul (RS) is the objective of  the group with more than 100 people among teachers, researchers, and UFRGS Agronomy students from  the State Foundation of Agricultural Research (FEPAGRO), from Zoo & Botanical Foundation of RS, from the University of  Passo Fundo, and from UFPel Agronomy Faculty. This research started in 2000 and covers from the search for native plants  to postharvest, including studies related to production and spreading of seedlings to molecular biology, study of medical properties, ornamental  uses, and  area recomposition.

The objective  is  to help social and economic development of farmers and traditional communities, as well as area recomposition. This research contributes to the  knowledge of species in relation to their geographic distribution, ways of production, genetic structure, and the definition  of the parameters of species preservation.

According to Paulo Vitor Dutra de Souza, project coordinator and  a Professor  at UFRGS Agronomy Faculty, a few years ago native plants were not valued. Since America’s colonisation agriculture evolution has  been marked by the introduction of exotic species and disdain for  autochthonous ones, which for a long time were  the livelihood of people who lived here. Tropical and subtropical countries have the largest diversity of vascular flora but the number of species that bear  fruits is proportionally  minimal.

According to Souza, this scenario started to change 20 years ago; furthermore, he adds that the study of native plants was academically undervalued. “We registered  projects but only exotic areas  such as viticulture and citriculture received investment. They said they do not have economic importance. Only those projects already in place really mattered to them”.

However, Souza states that it was not a Brazilian issue only, but a global trend. Twenty years ago he visited a nurseryman in Australia. He says that the jerivá was not valued in Brazil at that time, and people only planted royal palm, native from Australia. On the other hand, jerivá was the tree mostly planted in Australia; they did not have royal palm. “The world undervalues what is native but this is changing now and Brazil is appreciating what is native as well.”

From a  couple of years, with the help of architects and landscape designers, condominiums started investing on planting butiazeiros, pitangueiras, jabuticabeiras and other ornamental plants. Native plants also have been used to feed birds and urban landscaping “but we realised that we do not know native plants”, says Souza.

The study is divided into multiple lines of research. The prospecting  phase is when they go out in search of native plants throughout the state. Most of them are found with help of farmers or acquaintances, and all plants are georeferenced. Souza says  that even  students comment things such as ‘I have a pitangueira tree in my house, but that is different and has  big and colourful fruits’. The work starts from these indications, as well as with the investigation on these plants.

Dissemination by cloning

Souza coordinates the area of spreading seedlings by cloning  – the so-called vegetative dissemination, or by cutting in which a piece of a plant is collected and rooted in order to make a new plant identical to its mother-plant. Most of nurserymen produce the seedlings, which  creates  a diversity that is not always welcome. According to Souza, in order to commercialise fruits, it is important to have a standard as well as a high level of predictability; “If a farmer plants an orchard to sell fruits to the market this fruit must grow in a particular  moment, it has  to be big and pretty because, sadly, the market does not like ugly fruits; and people buy with their eyes.”

In order to  fit in a flat balcony or house, the technique can be used in smaller plants reproduction as well, such as bonsai. “But this must be done by cloning because the plants will have different sizes by seeding. Cloning is useful to select matrices with different purposes”, Souza states.

Professor Souza says that  his method is an adaptation of  the mini-garden technology, which is used by eucalypt farmers.  Additionally, he explains that one keeps the small plants in a planter, and each time it sprouts, one cuts off the new stems  and plant  it in the soil, thus achieving 20, 30 seedlings  per month. This is an easy commercial way of clone production. In the beginning, in order to encourage rooting,  it is necessary to irrigate the plant every two minutes, keeping air humidity at 90% to avoid dehydration. In four months the plants are full of fruits.

In some cases, dissemination is also made by grafting. This process can be used to facilitate plant development as well as to combine desirable characteristics of different plants. This technique is used with different parts of two plants  -  a root of one plant  with the top of the other plant. “We are testing everything to see if the plant takes root or not”, Souza explains. After that, the plants are taken to UFRGS Agricultural Experiment Station in order to be evaluated over the years.

(Inserir imagem 2) Clonal mini-gardens remained in greenhouses at UFRGS Agronomy Faculty. Photo by Gustavo Diehl/UFRGS

Medical properties

Native fruits nutraceutical and medical properties are also object of research. In a study, for example,  researchers analyse the amount of vitamin C in fruits. Souza points out  that myrtaceae, a family of plants such as pitangueira, guava tree, araçazeiro, and jabuticabeira, has great amount of vitamin C, and his research group noticed that in a native orchard of guabiju (Myrcianthes punges) there are trees that  produce twice the amount of vitamin C produced by trees standing just next to them.  Therefore,  the idea is to select the plants that produce more vitamins.

The studies also indicate that these fruits can help to fight  free radicals, and the oil extracted from the myrtaceae fruits is able to fight  salmonella.

Other economic potentials

Rural tourism is an alternative  economic way to use  unexplored native fruits, especially those in metropolitan region. A good idea, for example, would be the creation of systems similar to  “pick-your-own” , which is popular  in properties at Serra Gaúcha (mountain region), at viticulture area and in apple planting in São Joaquim (Santa Catarina), in which clients would visit orchards, pick the fruits themselves and pay for them.  Souza says that, in spite of allowing people to be familiar with native fruits of Rio Grande do Sul, “it’s not easy to find people to crop fruits. With this system the problem is solved and buyers have fun.”

There are also studies on plant flourishing, such as the study of an orchard of jabuticabeira that was part of rural tourism in Porto Alegre. The researchers noted that this specie flourishes after the dry season, when rain is constant. Based on that, Souza and Taís Altmann, his Phytotechnology MA supervisee, together with researchers from Agrometeorology, are developing studies in order to explain the reasons why jabuticabeiras flourish by using devices to evaluate temperature inside the plant, humidity, wind and soil water, and conducting experiments with different doses of irrigation in order to induce blooming in other seasons. Between spring and summer they could reach 4 to 5 blooming.

Araçá is an attractive fruit to birds and can be used as an alternative to feed these animals. Souza says that in viticulture birds  found near metropolitan regions are the worst plague because there are many of them but not enough food, and they attack the grapes.  One of the first studies he conducted 15 or 20 years ago was to help a friend who had a vineyard.  He planted many araçá trees and solved  the problem with the birds.

Souza says that native fruits, such as jerivá, are also a great option for urban forestation. With a root that will not ruin pavements and with a straight trunk, which avoids  contact with electric wires, this plant is easy to handle. According to Souza, another possibility is planting smaller trees such as pitangueira and feijoa (Acca sellowiana).

Main findings and diversity

According to Souza the group’s main findings are varieties among plants. “What really amazes us is the existing diversity of  native fruits and the different features  of plants – their size, blooming periods, type of fruits, and the amount of sugar, acid, vitamins, and nutraceutic components. He says that their main concern is keeping this variety alive.  An example of this diversity is the butiazeiros planted at the  Experiment Station -  from a single plant it is possible to notice  different plants in terms of size, bunch, and fruit size. According to Souza, the diversity is substantial  and it happens with all of them: pitanga, jabuticaba, among others. The facility with which plants are being multiplied comes as an additional surprise to the research group.  “From seedlings, they easily germinate and reproduce.  Our initial concern was with plants that are difficult to root out of cutting but we are not having any problem, with them,” Souza says.

Area Recovery

If on one hand the appreciation of native plants carries numerous possibilities, on the other hand, the growing search of it combined with lack of control could bring deterioration and disappearance of these plants. According to Souza, with native fruits being appreciated by everyone, there is a shortage of native seedlings. In consequence, there is the risk of people getting it from nature because a plant takes years to grow. Nowadays, no one wants to wait 10 years to get fruits. If it is a rich person, he/she would order an adult tree.

The researcher adds that they were worried, and still are, because native trees were disappearing, in fact, in some regions butiazais are still disappearing. In addition, companies are illegally cutting down butiazeiros to plant them in condominium. Another issue is deforestation for cattle farming, “this does not directly destroy butiazais, but every seed that falls on the ground or plant that germinates is eaten by the cattle. There is no renovation. In some years, like all organisms, they will die and we will not have renovation,” Souza says.

He celebrates the fact that there are studies geared at fencing pieces of land to stop animals from entering and to study how long it will take for these areas to regenerate. “I used to believe that butiazeiro took 10 years to bear fruits,  for example, but we know now that with proper care and fertilisation, in the third year this butiazeiro is producing fruits. At the Station we have plants whose bunches reach the ground.”

The relationship with farmers and society

The group´s main concern is to divulge the works by farmers,  nurserymen, and consumers. In addition to theses, dissertations, and articles, undergraduate modules were created on the subject, complemented by seminars, workshops, and outreach courses available to the community, such as the courses on home orchard and small space vegetable gardens.

Furthermore, the exchange of information with farmers during the research project is intense. Visits to orchards and nurseries are frequent, and some studies, such as the aforementioned study on the jabuticabeira blooming, are conducted directly in someone’s property, “and the farmer and his employees follow it; they participate in the daily practice with us; thus, information is automatically passed on to them”, says Souza.

The researcher points out that they are prepared to listen to farmers in all the areas the study covers. He gives the example of a farmer who called them because he was having  difficulty to climb a jabuticabeira to pick its fruits because it was too tall. Thus, “this allowed us to experiment with pruning. It is different from the peach and apple trees because  people have known how to properly prune them for over 200 years in order to get beautiful fruits. We are experimenting with different types of pruning in order to help farmers, especially because nowadays labor is scarce”, he explains.

Continuing Research

Although the first project, which was sponsored by CNPq (National Council for Scientific and Technological Development), is finished, the research group continues working. With regard to dissemination, for example, cloning was tested in some species. “We did not have problems producing pitangueiras, araçazeiros, and jabuticabeiras”, Souza states. Currently, the idea is to expand the study to new varieties such as pés de sete-capote, guabiroba, and guava. “We have also gathered 4 or 5 keystone species to work with in different lines of research, and are now trying to expand on it”, Souza adds.

The group has considerable amount of information on  butiazeiro; however, according to Souza, “ we haven´t yet managed to root a stem. For palm trees, dissemination is normally done only by seedling, and if we are thinking of standardisation, this is complicated because diversity is inevitable”. Thus, his group is also working with in vitro cultivation in order to create clones from meristem, a tissue that exists in most plants containing undifferentiated cells, which similarly to animal stem, are known for their capacity to divide themselves indefinitely, producing new cells that are necessry to the plant development.  “We also have new lines of research and great potential for their development. It’s challenging, but yet rewarding”, Souza says.

The researcher also draws attention to the difficulties they faced due to the economic crisis and budget constraints. “As resources are really scarce, we were forced to reduce the area of study. Before, we used to cover the whole state, but now we have to reduce even costs with petrol and other expenses. We have plenty of material nearby so we did not stop working, and we will be able to carry on working for a few more years”, he concludes.

Translated by Joana da Silveira de Souza under the supervision of Professor Márcia Moura da Silva (UFRGS)

Portuguese version available at: http://www.ufrgs.br/secom/ciencia/pesquisadores-estudam-caracteristicas-e-potenciais-das-frutiferas-nativas-do-rio-grande-do-sul/

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