Guia Covid-19
Imprimir Republish

Agriculture

A seed to germinate

Northeastern region gains a new variety of pale-skinned, drought resistant peanut

embrapaSkin of the same color as the seed favors the industrial use of peanutsembrapa

If we set out all over Brazil asking who likes peanut brittle and peanut flour sweet few paçoca, very few, will reply no. Sweets made of peanut or even the pure nut, roasted or cooked, are part of the national preferences, particularly in the Northeastern region, which accounts for the second place in consumption in the country, with 50,000 tons of pods a year, although it only produces 13,000 tons. With such popularity and high protein content, peanuts should be more available in the fields of this region from the second half of next year onwards, when a new variety of seed developed by the Brazilian Agricultural Research Corporation (Embrapa) will become available to farmers. Called BRS Havana, it was specially prepared for the semi-arid northeast, with the characteristics of being resistant to drought and to yield a good productivity for the conditions of the region. Another important advantage of the new seed is its cream colored skin that covers the nuts, and not red, like the majority of those existing on the market.

A skin the color of the nut is extremely important for the farmer to sell his production to the sweets industries and other peanuts products. “As the cream skin is the same color as the seed, the factories can grind the nuts directly to make paste, sweets and savories, without bothering about the visual impurities left by the red skin”, says agronomist Roseane Cavalcanti dos Santos, responsible for the development of the BRS Havana seeds at Embrapa Cotton, in Campina Grande, in Paraíba. “With seed looking like the skin, one stage of the industrial processing is eliminated, in which they are skinned.”

Developed over a four year period, the new variety was planned to bring farmers another benefit. The new seeds result in average sized, upright plants, in the ideal form for the small and medium producers who pick them by hand, without any machinery, as occurs in a large part of the crops of the southeastern region, responsible for 80% of the domestic production (about 300,000 tons a year), which is often done in rotation with sugarcane.

Larger producers prefer the varieties that grow close to the ground, called runners, because they favor mechanical harvesting. Roseane also points out a nutritional gain in the new seed. “The preservation of the skin guarantees the consumer a larger dosage of vitamins of the B complex, such as riboflavin and thiamin. Moreover, the new seeds contain 27% of protein and a level oil content, 43%, which is a factor demanded by the market, because like this the product becomes less indigestible and has a better consistency for making peanut candy.”

To form the new seed, Roseane led a multidisciplinary team of researchers from Embrapa Cotton, from the Bahia Agricultural Development Corporation (EBDA), from the Pernambuco Agricultural Research Corporation (IPA), from Embrapa Coastal Tablelands, in Sergipe, and from the Federal University of Pernambuco. They used 250 types (also called accesses) of seed of the same commercial species of peanut, Arachis hypogaea. The main variety used to arrive at the BRS Havana was a type called Película Havana, ceded by the Campinas Agronomic Institute (IAC) and little used by the farmers of the southeastern region, where there are also other specific varieties with a cream film. At the moment, seeds with this kind of skin have been much sought after by Brazilian peanut producers, particularly from the southeastern and central-western regions of the country, which prefer the runner varieties, such as the IAC Caiapó.

“The problem is that the runner types, besides being adapted to the climate of the Southeast, which are not suitable for small and medium farmers, for growing very close to the ground and having a 120 to 140-day cycle, from planting to harvesting. The producers from the Northeast prefer cycles of 90 days and seeds that are very tolerant of drought”, says Roseane. The BRS Havana, besides having these characteristics, have a productivity similar to that of the Tatu variety, planted in the region, and has three to four seeds per pod. “In the rainy season (January to March) in the semi-arid, the BRS Havana produces between 1,800 and 2,500 kilos of pods per hectare (kg/ha), while the Caiapó, which has two seeds in each pod, has a production of between 2,300 and 3,500 kg/ha, although it needs a lot more water to develop, which calls for investments in irrigation and equipment for mechanized harvesting.”

Antifungal hybrid
The scientific advances in the cultivation of peanuts, one of the few commercial species of the legume family to give fruit under the ground (there are species of this family of legumes that give fruit under the ground – Arachis pintoi and A. glabrata – which have this characteristic), are also taking place in Brasilia, in Embrapa Genetic Resources and Biotechnology. There, a group of researchers, coordinated by agronomist José Francisco Valls, has developed hybrid peanut plants, resistant to late leaf spot, early leaf spot and peanut rust, diseases caused by funguses that can destroy up to 70% of the production.

“The funguses attack the leaves, which afterwards fall off, leaving the plant without photosynthesis. This means there is no growth of the nuts and productivity is reduced”, explains agronomist Alessandra Pereira Fávero. “What we did was to take the natural resistance against funguses of two wild species (not selected by man) to the commercial species, by means of crossbreeding.” The two species are Arachis ipaënsis and A. duranensis, originally from Bolivia and Argentina. Also under tests are crossbreedings of A. hypogaea with A. hoehnei (from the state of Mato Grosso do Sul), A. cardenasii (from Bolivia) and A. helodes (state of Mato Grosso), amongst others.

The first stage of the project was to cross the two wild species that generated sterile hybrid plants with 20 chromosomes. The problem is that the commercial species has 40 chromosomes, which makes crossbreeding impossible. The way out was to duplicate the chromosomes of the wild hybrids by a chemical process in the laboratory, using a substance called colchicine. With this, the wild peanut plants came to have 40 chromosomes and became fertile. It was therefore possible to carry out the crossbreeding of the wild hybrids with the commercial species in the normal way, with cross pollination of the flowers.

The crossbreedings resulted in fertile plants with 50% of the genome of the cultivated species and 50% of then wild one. In relation to the seeds, the hybrids have one or two nuts per pod, as happens with the wild species. The commercial ones have up to four nuts. “To arrive at more seeds in the pod, we need to do more crossbreeding, to improve the hybrid”, Alessandra reckons. This stage of improvement of the plant is going to begin with the planting of the new seeds at the IAC’s Experimental Station in the city of Pindorama, in São Paulo, under the care of researchers Sérgio Almeida de Moraes and Ignácio José de Godoy, also from the IAC. The work of both of them has already resulted in the development of five varieties in the last eight years, two of which are now being marketed.

Strategic collection
“The planting of the hybrids, which should begin by the end of this year, is also going to show us whether the resistance to funguses has prevailed in the hybrid seed”, Alessandra explains. If the results are corroborated in the field, the genetic usage of the wild peanuts may grow. At the headquarters of Embrapa Genetic Resources, seeds from 76 species of peanuts, from the 81 existing in the world, have been brought together. “One of the five that are missing is from the region of the city of Campo Grande, in Mato Grosso do Sul, and is extinct”, says Alessandra. In Brazil, 64 species were found, of which 47 exclusive to the country.

The cultivated species, according to the latest studies, arose in the area between the south of Bolivia and northeast of Argentina, although there is evidence of centers of variation (secondary habitats, probably the fruit of transportation and cultivation by humans) in the region of the Xingu river, in Mato Grosso, and in Peru. “The Indians, who were already cultivating peanuts when the Portuguese arrived in Brazil, must have spread the seeds throughout the Americas”, says Alessandra. Besides the development of new varieties of peanuts, more resistant to diseases, more productive, and adaptable to drought, the researches carried out at Embrapa may, in the future, help to repopulate deforested areas. Another possibility is offering genes that exercise some important and necessary function for experiments in transgenics, with the transfer of peanut genes to other species.

Republish