Lettuce seeds stored for five years.
Lettuce seeds stored for five years.

Researchers from UPM in collaboration with National Center for Genetic Resources Preservation have developed an innovative methodology to assess the quality of seeds stored by measuring their volatile compounds.

Recently, a group of researchers from Universidad Politécnica de Madrid (UPM) and National Center for Genetic Resources Preservation (USDA, USA) has developed an innovative methodology for early detection of loss of seed quality, which consists on the assessment of volatile compounds emitted by the seeds during their storage. This method will allow researchers to identify seed aging markers with a non-invasive method. This result can be of great interest for seed companies such as gene banks.

Seeds from both cultivated and wild plants can be stored during long periods of time, helping preserve plant biodiversity in the long term. However, seed longevity is not easily predictable because they vary depending on the species and even among the batches of seeds. While some desiccated seeds can survive for decades, others have a very short life.

One way or another, seeds inevitably lose quality and the capacity of germination as time passes. This means a huge risk of loss of plant material and waste of resources and efforts devoted in the collection and preservation of seeds in the past. So far, the viable method to assess the seed quality is to prove their viability through germination tests. However, germination tests are expensive and difficult to carry out in some species.

M. Elena González Benito and Sara Mira, two female researchers from PLANGER Germoplasma Vegetal group from UPM, specialized in the study and preservation of plant germplasm, have developed a new technology for early detection of loss of seed quality. Thus, air samples from the airtight containers where seeds are stored were extracted.

Later, the samples were analyzed through gas chromatography in order to identify the compounds released by the seeds during their storage, and finally, the identifying profile of each species was assessed and compared to the quality of the batches of seeds assessed in the germination tests.

Viable arugula seeds after ten years of storage. / Sara Mira.

The assessment of the gas compounds emitted by seeds during their storage provides a unique tool to face questions about mechanisms that causes aging in desiccated biological tissues. Besides, this result can be a suitable non-invasive method for early detection of seed aging. This research study was carried out in collaboration with National Center for Genetic Resources Preservation and was recently published in the Journal of Experimental Botany.

This work is framed in a research line of PLANGER group, assigned to School of Agricultural, Food and Biosystems Engineering at UPM, and aims to understand the mechanisms that cause seed aging. Firstly, the effects of the storage conditions (temperature, humidity and the gas atmosphere) on the loss of seed viability were studied.

Secondly, researchers aim to identify the seed aging markers. According to the two female researchers:  “research on biological processes responsible for seed aging is essential to reach our ultimate goal, and this process consists on fully optimizing the storage and preservation of seeds in both seed companies and gen banks, ensuring the maintenance of the collections in the future".