Genetic analysis of wheat grains using digital imaging and their relationship to enhance grain weight

Abstract

Phenomic characterization through digital imaging (DI) can capture the three dimensional variation in wheat grain size and shape using different image orientations. Digital imaging may help identifying genomic regions controlling grain morphology using association mapping with simple sequence repeats (SSRs) markers. Accordingly, seed shape phenotypic data of a core collection of 55 wheat genotypes, previously characterized for osmotic and drought tolerance, were produced using computer based Smart grain software. Measured dimensions included seed volume, area, perimeters, length, width, length to width ratio, circularity, horizontal deviation from ellipse (HDEV), vertical deviation from ellipse (VDEV), factor form density (FFD) etc. The thousand grain weight (TGW) was positively correlated with grain size direct measurements; however, VDEV, FFD and other derived grain attributes showed no or negative correlation with TGW. Digital imaging divided the genotypes correctly into well-defined clusters. The wheat genotypes studied were further grouped into two sub-clusters by the Bayesian structure analysis using unlinked SSR markers. A number of loci over various chromosomal regions were found associated to grain morphology by the genome wide analysis using mixed linear model (MLM) approach. A considerable number of marker-trait associations (MTAs) on chromosomes 1D and 2D may carry new alleles with potential to enhance grain weight due to the use of untapped wild accessions of Aegilops tauschii. Conclusively, we demonstrated the application of multiple approaches including high throughput phenotyping using DI complemented with genome wide association studies to identify candidate genomic regions underlying these traits, which allows a better understanding on molecular genetics of wheat grain weight.

Exploitation of Tolerance of Wheat Kernel Weight and Shape-Related Traits from Aegilops tauschii under Heat and Combined Heat-Drought Stresses

“…In agreement with Ali et al [40], we found that kernel area size was most closely associated with kernel perimeter length and then kernel length under all conditions. The candidate gene TraesCS2A02G099400 for marker 5357358 detected under OP conditions on chromosome 2A encodes a basic leucine zipper transcription factor (Table 3).…”

“…Rasheed et al [ 17 ] also reported a lower contribution of the D genome, though they used synthetic hexaploid wheat. This inconsistency could be attributed to the previous studies being conducted under non-stress conditions and/or to the diversity of the D genome in the materials used being narrower than the A and B genomes; our results are in agreement with Ali et al [ 40 ]. On the other hand, our findings reveal the uniqueness of the MSD panel as an effective and powerful platform for allele and gene mining in Ae.…”

Iron and zinc micronutrients and soil inoculation of Trichoderma harzianum enhance wheat grain quality and yield

“…The intensity of HMW-GS under different treatments was also measured by a computer software image J. For this purpose, the de-stained gel was scanned with a high-resolution scanner, converted to a grayscale image, and processed as previously described in Ali et al ( 2020 ) and Bonilla et al ( 2020 ).…”

TaNAC020 homoeologous genes are associated with higher thousand kernel weight and kernel length in Chinese wheat

“…Agronomic and physiological traits associated with TaNAC020s haplotypes TKW and KL are among the most important agronomic traits and are often under high selection pressure. In wheat, kernel weight and kernel size have a positive correlation between them (Ali et al, 2020). High heritability values of TKW have proved that it is phenotypically a stable yield parameter, which continuously attracts wheat breeder attention because TKW has continuously improved during evolution, and this improvement may be due to the accumulation of preferred haplotypes associated with this trait.…”