“PLANT-SOIL INTERACTIONS” – Scientific Achievements – Research Group 1n
Research Group
Genetic resources, nutrient use efficiency and stress tolerance in cereals
The project KP-06-N31/17, which ended in 2025, aligns with the European and global efforts toward sustainable agriculture and the effective use of plant genetic resources. Its main objective was to clarify the molecular structure and genetic variability of the Bulgarian common wheat germplasm, as well as the genetic architecture of traits determining grain yield and grain quality.
Main Scientific Achievements
- For the first time, the Bulgarian common wheat germplasm has been characterized at the DNA level through whole‑genome screening using SNP (single nucleotide polymorphism) markers. A collection of 179 Bulgarian varieties developed since the early 20th century has been analyzed.
- The population structure has been defined (Fig. 1), distinguishing subpopulations of historical and modern varieties, and the extent of gene flow associated with breeding activities has been established.
- Natural phenotypic variation has been analyzed for key agronomic traits: plant height, thousand‑kernel weight, and grain protein content.
- Genomic regions in the wheat chromosomes controlling these traits have been mapped together with their associated specific DNA markers, and potential candidate genes within these regions have been identified (Fig. 2).
- In an international collection of 255 accessions from 27 countries, variation in grain protein content has been examined, and marker–trait associations and potential candidate genes have been identified (Fig. 3).
Significance of the Results
The identified functional DNA markers have the potential to support precise selection and to accelerate the development of high-yielding and high-quality wheat varieties. The results may facilitate the choice of suitable parental lines and the targeted use of historical germplasm. Several Bulgarian varieties stand out as potential sources of genes for the simultaneous improvement of thousand-kernel weight and grain protein content. The project contributes to global strategies for sustainable agriculture, increased crop productivity, and food security in the context of climate change and a growing world population.
Fig. 1. Genetic structure of Bulgarian old and modern bread wheat accessions. (A) Estimation of the optimal number of clusters, defined by the Evanno method. (B) Inferred structure of a panel of 179 accessions. Each individual is represented by a colored bar with a length proportional to the estimated membership to each of the three clusters. (C) Plots in right depict the clusters as separate subpopulations.
Fig. 2. Heatmap showing gene expression levels (log2 tpm, transcripts per million) of selected putative genes controlling grain protein content (GPC) and thousand kernel weight (TKW) in wheat.
Fig. 3. Manhattan plots (left) and Q-Q plots of genome-wide association scan for grain protein content in an association panel of 255 diverse wheat accessions,
Abiotic stress has a negative impact on crop plants’ productivity. Wheat is among the most important cereals in conventional agriculture as a major nutrition source. The increasing interest in a healthy lifestyle has led to the demand for foods with higher nutritional value and better grain properties compared to traditional cereals. In this regard, einkorn is among the main contenders for growing in sustainable farming. Scientific data indicated higher nutritional and technological properties of the grain and better performance under diverse types of abiotic stress (low nitrogen, UV stress, drought and salinity) on nitrogen assimilation in wheat and einkorn was investigated based on the assessment of the activity of key enzymes from nitrogen metabolism (HP and GS). The intensity of the applied stress was investigated through assessment of antioxidant and anti-radical activity in both plant species (wheat and einkorn) in response to suboptimal values of various abiotic factors such as high UV irradiation, increased salinity, lower N and water availability.
