Embrapa will showcase soybean varieties that differ from the commercial standard.

Dwarf soybean plants, soybean plants without pubescence (hairless), and even those with wavy leaves are among the curiosities that Embrapa Soja will present at the Technology Showcase during the Show Rural Coopavel, which will be held from February 9th to 13th in Cascavel. Researchers selected different types of soybeans from among the approximately 65 accessions stored in Embrapa's Active Germplasm Bank (BAG) – one of the three largest soybean collections in the world.

The goal is to show how the genetic variability of the crop is expressed in visual (phenotypic) characteristics, little known to the public. “The germplasm bank is restricted to research institutions, and the general community doesn't have access to it. For the first time, we are visually showing this richness,” says researcher Marcelo Fernandes de Oliveira, from Embrapa Soja. According to him, the aim is to visually demonstrate something that is not normally present in commercial soybeans.

Semi-determinate soybeans

One of the distinguishing features will be the semi-determinate soybean, considered the first of its kind to be proven. According to the researcher, this material represents an intermediate stage between the determinate and indeterminate soybeans available on the market.

“Determinate soybeans flower almost all at once and, once flowering begins, stop growing. This was the type used until the 2000s. Indeterminate soybeans, on the other hand, begin flowering and continue for 20 to 25 days, doubling in size during this period—and today represent more than 90% of commercial cultivars,” explains Fernandes.

Semi-determinate soybeans, on the other hand, exhibit intermediate behavior. "They continue flowering, but don't double in size. They grow about 30% to 40% and have a different architecture, with shorter internodes, a greater number of pods per node, and an umbrella-shaped tip, known as a 'cachopa'," the researcher explains.

According to the researcher, studies indicate that this type of architecture may be associated with productivity gains, although more work is still needed to confirm its agronomic potential on a commercial scale. "We are making progress in crossbreeding and pre-breeding to better understand this material, especially because there is a lot of confusion in classifying cultivars as semi-determinate," says Fernandes.

Beyond the commercial standard

In addition to semi-determinate soybeans, Embrapa Soja will exhibit varieties with characteristics rarely seen in the field, with flower, leaf, and pod features different from traditional soybeans.

“The idea is not to say that all these characteristics are better or worse, but to show that they exist. Some have advantages, others have disadvantages. Soybeans without pubescence, for example, are excellent for human consumption, such as edamame, but may be more susceptible to stink bug attacks,” explains the researcher. Therefore, scientific curation can establish commercial advantages for different soybean niches.

Genetical diversity

According to the researcher, the richness of the Active Germplasm Bank is directly linked to the genetic security of the crop. “The greatest genetic variability is in the center of origin of soybeans, which is China, and in other secondary centers such as Japan and Korea. Many characteristics that were lost over time are still preserved in these banks,” says Fernandes.

This diversity is fundamental to facing future challenges. “If an extreme environmental condition arises one day, whether biotic or abiotic, some of these plants may have the necessary characteristics to survive. This applies to drought tolerance, photosynthetic efficiency, plant architecture, or resistance to pests and diseases,” says the researcher.