Scientists work on the development of peanut variety resistant to smut

With more than 800 thousand tones sold abroad each year, Argentina is one of the leading exporters of peanuts in the world. However, the local production has been affected by smut, a disease caused by fungi Thecaphora freís, which destroys the seeds of the fruits.

To provide a solution to this problem that leads to loses of almost 40% of plantations, CONICET researchers participate in projects that aim to develop peanut resistant to smut. For this reason, they identified sources of resistance in wild species of Arachis as well as in old breeds and developed hybrids compatible with the varieties cultivated extensively for the industry.

The research work was jointly conducted with ‘El Carmen Hatchery’, the Universidad Nacional de Río Cuarto, the  Universidad Nacional de Córdoba, the Universidad Nacional del Nordeste and the National Peanut Research Laboratory (NPRL). The journals that published it were CropScience and PlosOne. Considering the development of these materials, the researchers estimate that in a few years there will be diverse commercial varieties of peanuts resistant to smut, what will recover the average performance of the peanut crop in Argentina.

“Smut is an endemic disease of Argentina that causes loses of 40% in the production. For this reason, it is important to work on the solution for this problem. It is hard to find foreign researchers interested in this subject because they do not have it,” says one of the authors of the study, CONICET principal researcher at the  Instituto de Botánica del Nordeste (IBONE, CONICET – UNNE), Guillermo Seijo.

“Our contribution was to systematize the existing knowledge of the preliminary tests of peanut breed resistant to smut, which were obtained by the El Carmen through different improvement methodologies. Particularly, we used genetic tools to identify the sources of the resistance and the available resources in old breeds and in wild species to obtain it”, explains Francisco de Blas, PhD fellow of CONICET at the Instituto Multidisciplinario de Biología Vegetal (IMBIV, CONICET – UNC).

One of the tasks was to obtain a ‘threehybrid’ from the wild species Arachis correntina, Arachis cardenasii and Arachis batizocoi, whose chromosomes were duplicated to be compatible with the commercial variety Arachis hypogaea. In the second one, the resistance was transferred from old peanut breeds of South America. In both cases, scientists developed populations to study the genetic structure of the character and enable the development of genetic markers linked to resistance.

The study aims at expanding the existing variability in commercial varieties through the development of pre-improvement materials, which still present character of wild species or old breeds that have no value for the industry. These materials have already been incorporated into the breeding programs that seek to develop commercial varieties resistant to smut in the short term.

“We have managed to transfer the resistance of these materials, which behave as resistant, to segregating populations for generic and genomic studies of character,” de Blas says. Now, the researchers work to determine which portions of genome are linked to resistance. For the researchers, in the near future, it will be possible to identify the genomic regions associated to resistance and develop DNA markers to accelerate the programs to obtain resistant commercial varieties.

Although the way to obtain commercial peanut resistant to smut is quite advanced, the main objective of CONICET scientists is to determine the genetic structure of resistance and have the tools to accelerate the process of generating new varieties with better characteristics. “To achieve this, the collaboration between scientific institutions and the productive sector is vital. In this project, our relationship with ‘El Carmen Hatchery’ was essential and we hope to continue obtaining good results from this interaction,” de Blas concludes.