Genome-wide superior alleles, haplotypes and candidate genes associated with tolerance on sodic-dispersive soils in wheat (Triticum aestivum L.)

Key message The pleiotropic SNPs/haplotypes, overlapping genes (metal ion binding, photosynthesis), and homozygous/biallelic SNPs and transcription factors (HTH myb-type and BHLH) hold great potential for improving wheat yield potential on sodic-dispersive soils. Abstract Sodic-dispersive soils have multiple subsoil constraints including poor soil structure, alkaline pH and subsoil toxic elemental ion concentration, affecting growth and development in wheat. Tolerance is required at all developmental stages to enhance wheat yield potential on such soils. An in-depth investigation of genome-wide associations was conducted using a field phenotypic data of 206 diverse Focused Identification of Germplasm Strategy (FIGS) wheat lines for two consecutive years from different sodic and non-sodic plots and the exome targeted genotyping by sequencing (tGBS) assay. A total of 39 quantitative trait SNPs (QTSs), including 18 haplotypes were identified on chromosome 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 5A, 5D, 6B, 7A, 7B, 7D for yield and yield-components tolerance. Among these, three QTSs had common associations for multiple traits, indicating pleiotropism and four QTSs had close associations for multiple traits, within 32.38 Mb. The overlapping metal ion binding (Mn, Ca, Zn and Al) and photosynthesis genes and transcription factors (PHD-, Dof-, HTH myb-, BHLH-, PDZ_6-domain) identified are known to be highly regulated during germination, maximum stem elongation, anthesis, and grain development stages. The homozygous/biallelic SNPs having allele frequency above 30% were identified for yield and crop establishment/plants m−2. These SNPs correspond to HTH myb-type and BHLH transcription factors, brassinosteroid signalling pathway, kinase activity, ATP and chitin binding activity. These resources are valuable in haplotype-based breeding and genome editing to improve yield potential on sodic-dispersive soils.

Genome-Wide Superior Alleles, Haplotypes and Candidate Genes Associated With Tolerance on Sodic-Dispersive Soils in Wheat (Triticum Aestivum L.)

Sodic-dispersive soils have multiple subsoil constraints including poor soil structure, alkaline pH and subsoil toxic elemental ion concentration, affecting growth and development in wheat. Tolerance is required at all developmental stages to enhance wheat yield potential on such soils. An in-depth investigation of genome-wide associations was conducted using a field phenotypic data of 206 diverse Focused Identification of Germplasm Strategy (FIGS) wheat lines for two consecutive years from different sodic and non-sodic plots and the exome targeted genotyping by sequencing (tGBS) assay. A total of 39 quantitative trait SNPs (QTSs), including 18 haplotypes were identified on chromosome 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 5A, 5D, 6B, 7A, 7B, 7D for yield and yield-components tolerance. Among these, three QTSs had common associations for multiple traits, indicating pleiotropism and four QTSs had close associations for multiple traits, within 32.38 Mb. The overlapping metal ion binding (Mn, Ca, Zn and Al) and photosynthesis genes, and transcription factors (PHD-, Dof-, HTH myb-, BHLH-, PDZ_6-domain) identified are known to be highly regulated during germination, maximum stem elongation, anthesis, and grain development stages. The homozygous/biallelic SNPs having allele frequency above 30% were identified for yield and crop establishment/plants m-2. These SNPs correspond to HTH myb-type and BHLH transcription factors, brassinosteroid signaling pathway, kinase activity, ATP and chitin binding activity. These resources are valuable in haplotype-based breeding and genome editing to improve yield potential on sodic-dispersive soils.

GEODYNAMICS

Purpose. The aim of the research is mathematical analysis and forecasting of dispersive soils behaviour based on the study of inclinometric observations data in the area of the natural-technical system of the Dnister PSPP. Methodology. The research methodology is based on mathematical analysis and modelling of processes occurring in the mountain massif on which the Dnister PSPP is located, using the finite element method. Results. The paper presents an analysis of the results of geotechnical monitoring of the behaviour of dispersive soils, implemented on the basis of inclinometric measurements on the territory of the Dnister PSPP. Quantitative parameters of horizontal displacement distribution in inclinometric wells are established. They made it possible to detect negative dynamics in the geological horizons N1-2ap and N1p+v, which is apparently caused by technogenic load caused by the Dnister upper reservoir. The behaviour of dispersive soils under the influence of natural and technogenic loads has been modelled. Based on the simulation results, the change of the sign of deformations under the influence of additional load, which can be the filling of the Dnister upper reservoir, is confirmed. Obviously, the use of this method alone does not allow full detecting and tracking modern geological, seismic and geodynamic processes. A combination and detailed analysis of different monitoring methods (geophysical, geodetic, parametric, vibrometric, hydrogeological, temperature, visual-instrumental and others), as well as modelling the behaviour of the object under the influence of natural and technogenic factors is optimal. Such simulations could be used in the design of other objects of this type, so this is a promising area for further research. Originality. For the first time, a mathematical analysis and forecasting of the behaviour of dispersed soils in the area of the natural and technical system of the Dnister PSPP was conducted on the basis of studying the data of inclinometric observations. Practical significance. The proposed technique can be used in the design of other objects of this type, as modelling the behaviour of the object under the influence of natural and technogenic factors makes it possible to assess possible risks and prevent them.

Effect of Silica Fume as a Waste Material for Sustainable Environment on the Stabilization and Dynamic Behavior of Dispersive Soil

The use of dispersive soils, which are common in many parts of the world, in engineering applications such as water structures, earthen dams and road embankments is possible with their improvement. Recently, the effects of different chemicals on the stabilization of dispersive soils have been investigated. The use of waste materials in stabilization is preferred both because of the more sustainable environment and the economic advantages it provides. The use of silica fume (SF) as a waste material in different engineering applications provides an important advantage in environmentally and economically sustainable ways. Many studies have been carried out regarding silica fume, especially in the construction industry. Although SF is used in many industries, there is no study about its potential impact on the stabilization and dynamic properties of dispersive soils. In this study, first, Atterberg limits and standard Proctor compaction tests were performed on the mixtures prepared by adding different SF percentages (0, 5, 10, 15, 20, 25 and 30%). Afterward, pinhole tests and resonant column tests were performed to determine dispersibility and dynamic properties on the samples prepared by compaction characteristics for each SF percentage reached. In general, it was determined that SF contributed to a change in soil class, and improvement in dispersibility and dynamic properties of the soil sample, depending on SF content; positive effects of SF were observed in terms of shallow soil improvement.