Dataset Information

Variation Among Spring Wheat (Triticum aestivum L.) Genotypes in Response to the Drought Stress. II-Root System Structure.

ABSTRACT: (1) Background: The study analyzed wheat morphological traits to assess the role of roots structure in the tolerance of drought and to recognize the mechanisms of root structure adjustment to dry soil environment. (2) Methods: Root-box and root-basket methods were applied to maintain an intact root system for analysis. (3) Results: Phenotypic differences among six genotypes with variable drought susceptibility index were found. Under drought, the resistant genotypes lowered their shoot-to-root ratio. Dry matter, number, length, and diameter of nodal and lateral roots were higher in drought-tolerant genotypes than in sensitive ones. The differences in the surface area of the roots were greater in the upper parts of the root system (in the soil layer between 0 and 15 cm) and resulted from the growth of roots of the tolerant plant at an angle of 0-30° and 30-60°. (4) Conclusions: Regulation of root bending in a more downward direction can be important but is not a priority in avoiding drought effects by tolerant plants. If this trait is reduced and accompanied by restricted root development in the upper part of the soil, it becomes a critical factor promoting plant sensitivity to water-limiting conditions.

SUBMITTER: Grzesiak MT

PROVIDER: S-EPMC6963452 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Variation Among Spring Wheat (<i>Triticum aestivum</i> L.) Genotypes in Response to the Drought Stress. II-Root System Structure.

Grzesiak Maciej T MT Hordyńska Natalia N Maksymowicz Anna A Grzesiak Stanisław S Szechyńska-Hebda Magdalena M

Plants (Basel, Switzerland) 20191208 12

(1) Background: The study analyzed wheat morphological traits to assess the role of roots structure in the tolerance of drought and to recognize the mechanisms of root structure adjustment to dry soil environment. (2) Methods: Root-box and root-basket methods were applied to maintain an intact root system for analysis. (3) Results: Phenotypic differences among six genotypes with variable drought susceptibility index were found. Under drought, the resistant genotypes lowered their shoot-to-root r ...[more]

PMID: 31817986

Similar Datasets

Project description:Wheat is the most widely grown and consumed crop because of its economic and social benefits. This crop is more important globally for food and feed, and its productivity is particularly vulnerable to abiotic factors. In this study, 40 wheat genotypes were studied to access the drought tolerance level using completely randomized design (CRD) in 250 ml disposable cups through morpho-physiological attributes at seedling stage. The wheat germplasm was tested under normal and two drought stress level D1 (50% field capacity) and D2 (75% field capacity) for different seedling attributes such as germination percentage (GP), chlorophyll content (CC), shoot length (SL), root length (RL), shoot fresh weight (SFW), root fresh weight (RFW), seedling fresh weight (SDFW), shoot dry weight (SDW), root dry weight (RDW), relative water content (RWC), root/shoot ratio (RS), and seedling dry weight (SeDW). The results of analysis of variance (ANOVA) and spider analysis indicate that significant amount of genetic variation was present and behavior of studied germplasm showed different behavior in different environment. The correlation analysis showed that root length has significantly positive association with root/shoot ratio, dry weight, and fresh weight while negatively correlated with shoot length and relative water content. Based on the positively associated traits, the studied genetic material would improve genetic gain for drought tolerance. The multivariate analysis showed that out 13 principal components only five PCs were significant and has eigenvalue > 1, cumulatively showed 82.33, 83.07, and 97.34% of total variation under normal, D1 and D2 conditions, respectively. Significantly, the result of spider graph and multivariate analysis showed that genotypes G47, G48, G65, G68, and G80 performed well in all drought stress conditions and considered as drought-tolerant genotypes. The best performing genotypes can be used in future breeding programs. The selection on the bases of studied attributes is effective for development of drought-tolerant and high-yielding varieties for sustainable food security.

Project description:BACKGROUND:Appropriate information about genetic diversity and population structure of germplasm improves the efficiency of plant breeding. The low productivity of Nepali bread wheat (Triticum aestivum L.) is a major concern particularly since Nepal is ranked the 4th most vulnerable nation globally to climate change. The genetic diversity and population structure of Nepali spring wheat have not been reported. This study aims to improve the exploitation of more diverse and under-utilized genetic resources to contribute to current and future breeding efforts for global food security. RESULTS:We used genotyping-by-sequencing (GBS) to characterize a panel of 318 spring wheat accessions from Nepal including 166 landraces, 115 CIMMYT advanced lines, and 34 Nepali released varieties. We identified 95?K high-quality SNPs. The greatest genetic diversity was observed among the landraces, followed by CIMMYT lines, and released varieties. Though we expected only 3 groupings corresponding to these 3 seed origins, the population structure revealed two large, distinct subpopulations along with two smaller and scattered subpopulations in between, with significant admixture. This result was confirmed by principal component analysis (PCA) and UPGMA distance-based clustering. The pattern of LD decay differed between subpopulations, ranging from 60 to 150 Kb. We discuss the possibility that germplasm explorations during the 1970s-1990s may have mistakenly collected exotic germplasm instead of local landraces and/or collected materials that had already cross-hybridized since exotic germplasm was introduced starting in the 1950s. CONCLUSION:We suggest that only a subset of wheat "landraces" in Nepal are authentic which this study has identified. Targeting these authentic landraces may accelerate local breeding programs to improve the food security of this climate-vulnerable nation. Overall, this study provides a novel understanding of the genetic diversity of wheat in Nepal and this may contribute to global wheat breeding initiatives.

Project description:BackgroundSingle nucleotide polymorphisms (SNPs) are ideally suited for the construction of high-resolution genetic maps, studying population evolutionary history and performing genome-wide association mapping experiments. Here, we used a genome-wide set of 1536 SNPs to study linkage disequilibrium (LD) and population structure in a panel of 478 spring and winter wheat cultivars (Triticum aestivum) from 17 populations across the United States and Mexico.ResultsMost of the wheat oligo pool assay (OPA) SNPs that were polymorphic within the complete set of 478 cultivars were also polymorphic in all subpopulations. Higher levels of genetic differentiation were observed among wheat lines within populations than among populations. A total of nine genetically distinct clusters were identified, suggesting that some of the pre-defined populations shared significant proportion of genetic ancestry. Estimates of population structure (F(ST)) at individual loci showed a high level of heterogeneity across the genome. In addition, seven genomic regions with elevated F(ST) were detected between the spring and winter wheat populations. Some of these regions overlapped with previously mapped flowering time QTL. Across all populations, the highest extent of significant LD was observed in the wheat D-genome, followed by lower LD in the A- and B-genomes. The differences in the extent of LD among populations and genomes were mostly driven by differences in long-range LD ( > 10 cM).ConclusionsGenome- and population-specific patterns of genetic differentiation and LD were discovered in the populations of wheat cultivars from different geographic regions. Our study demonstrated that the estimates of population structure between spring and winter wheat lines can identify genomic regions harboring candidate genes involved in the regulation of growth habit. Variation in LD suggests that breeding and selection had a different impact on each wheat genome both within and among populations. The higher extent of LD in the wheat D-genome versus the A- and B-genomes likely reflects the episodes of recent introgression and population bottleneck accompanying the origin of hexaploid wheat. The assessment of LD and population structure in this assembled panel of diverse lines provides critical information for the development of genetic resources for genome-wide association mapping of agronomically important traits in wheat.

Project description:Androgenesis is potentially the most effective technique for doubled haploid production of wheat. It is not however widely used in breeding programmes due to its main limitation: the genotype dependence. Due to genetic differences between spring and winter wheat, it was assumed that both phenotypes are different in their capacity to conduct androgenesis. And so, the aim of this investigation was to verify the effectiveness of androgenesis induction and plant regeneration of spring and winter wheat genotypes while considering varying amounts of growth hormones in the induction medium. Fifteen genotypes of spring wheat and fifteen of winter wheat were used in the experiment. Six hundred anthers of each of the 30 genotypes were plated and analysed. Previous studies have allowed selection of the best medium for wheat androgenesis and a combination of growth hormones that are the most effective in stimulating microspore proliferation. Therefore, C17 induction media with two combinations of growth hormones were used: I-supplemented only by auxins (2,4-D and dicamba), and II-supplemented by auxin and cytokinin (2,4-D and kinetin). Data was recorded according to the efficiency of androgenic structure formation (ASF), green plant regeneration (GPR), and albino plant regeneration (APR). The results showed that the induction and regeneration of androgenesis in the spring wheat were more efficient than in the winter ones. The spring genotypes formed more androgenic structures and green plants on anthers plated on the medium supplemented only by auxins, in contrast to the winter genotypes which were better induced and regenerated on the medium supplemented by auxin and cytokinin. The study showed that to increase the efficiency of androgenesis, it is necessary to select appropriate factors such as concentration and type of hormones in medium composition, affecting the course of the culturing procedure according to the winter or spring phenotype of donor plants.

Dataset Information

Variation Among Spring Wheat (Triticum aestivum L.) Genotypes in Response to the Drought Stress. II-Root System Structure.

Publications

Variation Among Spring Wheat (<i>Triticum aestivum</i> L.) Genotypes in Response to the Drought Stress. II-Root System Structure.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets