NSU scientists have established how the color of the grain is related to the terms of its storage and germination

Candidate of Biological Sciences, Associate Professor of the Department of Natural Sciences of the Novosibirsk State University Dmitry Afonnikov and Assistant of the Mathematical Center in Akademgorodok Evgeny Komyshev together with the Institute of Cytology and Genetics SB RAS and the Institute of Genetics and Agricultural Plant Studies (Gatersleben, Germany) using the method of digital image analysis, studied the morphological characteristics of the grain and the color of its shell for 44 recombinant inbred lines (RIL) of common wheat, which were grown in four different seasons: 2003, 2004, 2009 and 2014. For 19 RILs of the same seasons, the researchers evaluated the germination. Such a study of grain stored in a genetic bank for several years has never been carried out by anyone before.

The shell protects the grain from external influences, therefore its safety and functions are closely related to such characteristics as germination, viability, resistance to long-term storage. An important role is played by plant pigments: they perform protective functions at the molecular level. It is known, for example, that red-colored wheat grains are more resistant to premature germination and less susceptible to moisture swelling, which boosts their germination.

Dmitry Afonnikov commented about the uniqueness of the study:

In world scientific practice, remote methods for determining the "health" of seeds (diseases, mechanical damage, etc.) are already being developed. However, in these cases, a change in the color of the grains that is noticeable to the naked eye and its relationship with germination was studied either under conditions of artificial aging (heating) or during storage for no more than a year. Together with the Institute of Cytology and Genetics SB RAS and Dr. Andreas Berner from the Institute of Agricultural Plant Genetics, we looked at how changes in grain color will manifest themselves during a long storage period in the gene bank (when grains are stored at negative temperatures and low humidity in sealed packaging).

Based on the results of ANOVA and correlation analysis, scientists found that storage time does not significantly affect the variability of seed size and shape traits, but significantly affects color traits: approximately 80% of traits (44 out of 48) change significantly during long-term storage. At the same time, the longer the shelf life, the more red the grains have. Unlike experiments on artificial aging, in which the shell of the grains darkens, the scientists found that when stored in the conditions of the genebank, it became lighter.

Dmitry also commented:

When exposed to environmental conditions, including long-term storage, some of the pigments decompose, their concentration in the shell changes, which can be determined by the change in the color of the grains. The analysis of digital images that we used in our work allows us to catch even very slight changes in the color of the grain shell. In the future, this can be used to solve such practical problems as a quick assessment of the physiological state of the grain (the duration of its storage) or the prediction of its germination.

Published in the "Plants" journal, the results are important not only for seed producers, but also for gene banks, maintaining genetic collections.