Population Structure of Modern Winter Wheat Accessions from Central Asia

Abstract

Despite the importance of winter wheat in Central Asian countries, there are limited reports describing their diversity within this region. In this study, the population structures of 115 modern winter wheat cultivars from four Central Asian countries were compared to germplasms from six other geographic origins using 10,746 polymorphic single-nucleotide polymorphism (SNP) markers. After applying the STRUCTURE package, we found that in terms of the most optimal K steps, samples from Kazakhstan and Kyrgyzstan were grouped together with samples from Russia, while samples from Tajikistan and Uzbekistan were grouped with samples from Afghanistan. The mean value of Nei’s genetic diversity index for the germplasm from four groups from Central Asia was 0.261, which is comparable to that of the six other groups studied: Europe, Australia, the USA, Afghanistan, Turkey, and Russia. The Principal Coordinate Analysis (PCoA) showed that samples from Kyrgyzstan, Tajikistan, and Uzbekistan were close to samples from Turkey, while Kazakh accessions were located near samples from Russia. The evaluation of 10,746 SNPs in Central Asian wheat suggested that 1006 markers had opposing allele frequencies. Further assessment of the physical positions of these 1006 SNPs in the Wheat Ensembl database indicated that most of these markers are constituents of genes associated with plant stress tolerance and adaptability. Therefore, the SNP markers identified can be effectively used in regional winter wheat breeding projects for facilitating plant adaptation and stress resistance.

Association Mapping of Quantitative Trait Loci for Agronomic Traits in a Winter Wheat Collection Grown in Kazakhstan

“…However, due to predicted population growth, climate change, and political instability, there is a worldwide demand for greater wheat production [2], including in Central Asia. In the Central Asian region, wheat is grown on more than 15 million hectares (ha) of land with an average yield of 1.4 tones/ha [3], which is significantly lower than that in advanced agricultural countries, such as in USA (3.0 tones/ha in 2021-2022) [4]. Consequently, to increase the wheat production potential in this region, there is a necessity to generate new cultivars with higher yield and yield stability and increased resistance/tolerance to biotic and abiotic stresses [5].…”

“…Winter wheat is sown in the autumn and differs from spring wheat in its expression of the vernalization response, which is controlled by Vrn genes [8]. In Central Asia, the yield of winter wheat (3.1 t/ha in 2020) is nearly three times higher than that of spring wheat (1.1 t/ha in 2020), which is the type predominantly grown in Kazakhstan [3]. Still, there are potentials to increase the yield of winter wheat up to the level achieved in developed countries.…”

“…As seen from these studies, the success of each GWAS relies on the availability of diverse germplasm. Therefore, to evaluate untapped local germplasm, the CAWBIN (Central Asian Wheat Breeding Initiative) was recently launched as a collective effort of Central Asian and British scientists in Kazakhstan to establish a bank of genotypes of winter wheat collected from Central Asia [3]. The CAWBIN winter wheat collection consists of 277 accessions, including 115 samples from Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan) [3].…”

“…Therefore, to evaluate untapped local germplasm, the CAWBIN (Central Asian Wheat Breeding Initiative) was recently launched as a collective effort of Central Asian and British scientists in Kazakhstan to establish a bank of genotypes of winter wheat collected from Central Asia [3]. The CAWBIN winter wheat collection consists of 277 accessions, including 115 samples from Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan) [3]. Another issue is the consideration of genotype-environment interaction patterns, as a survey of the published GWAS articles for cereal crops, including winter wheat types [4,31], suggests a strong influence of the growth environment on the detection of QTLs for yield components.…”

Phenotypic Variation of Winter Wheat Collection From Central Asia Harvested in Kazakhstan

“…The Central Asia region includes five former Soviet Union Republics, including Kazakhstan, Uzbekistan, Turkmenistan, Kyrgyzstan, and Tajikistan, and they collectively grow wheat in an area of over 15 million ha [1]. Kazakhstan is one of the top 10 bread wheat producers and exporters in the world marketplace [2,3]. According to the Foreign Agricultural Service of the US Department of Agriculture (USDA), wheat production in Kazakhstan in 2022-2023 is expected to reach 16.0 million tons [4].…”