Evaluation of genetic variability and relatedness among eight Centaurea species through CAAT-box derived polymorphism (CBDP) and start codon targeted polymorphism (SCoT) markers

Molecular and agro-morphological characterization of new barley genotypes in arid environments

BACKGROUND

Genetic diversity, population structure, agro-morphological traits, and molecular characteristics, are crucial for either preserving genetic resources or developing new cultivars. Due to climate change, water availability for agricultural use is progressively diminishing. This study used 100 molecular markers (25 TRAP, 22 SRAP, 23 ISTR, and 30 SSR). Additionally, 15 morphological characteristics were utilized to evaluate the optimal agronomic traits of 12 different barley genotypes under arid conditions.

RESULTS

Substantial variations, ranging from significant to highly significant, were observed in the 15 agromorphological parameters evaluated among the 12 genotypes. The KSU-B101 barley genotype demonstrated superior performance in five specific traits: spike number per plant, 100-grain weight, spike number per square meter, harvest index, and grain yield. These results indicate its potential for achieving high yields in arid regions. The Sahrawy barley genotype exhibited the highest values across five parameters, namely leaf area, spike weight per plant, spike length, spike weight per square meter, and biological yield, making it a promising candidate for animal feed. The KSU-B105 genotype exhibited early maturity and a high grain count per spike, which reflects its early maturity and ability to produce a high number of grains per spike. This suggests its suitability for both animal feed and human food in arid areas. Based on marker data, the molecular study found that the similarity coefficients between the barley genotypes ranged from 0.48 to 0.80, with an average of 0.64. The dendrogram constructed from these data revealed three distinct clusters with a similarity coefficient of 0.80. Notably, the correlation between the dendrogram and its similarity matrix was high (0.903), indicating its accuracy in depicting the genetic relationships. The combined analysis revealed a moderate correlation between the morphological and molecular analysis, suggesting alignment between the two characterization methods.

CONCLUSIONS

The morphological and molecular analyses of the 12 barley genotypes in this study effectively revealed the varied genetic characteristics of their agro-performance in arid conditions. KSU-B101, Sahrawy, and KSU-B105 have emerged as promising candidates for different agricultural applications in arid regions. Further research on these genotypes could reveal their full potential for breeding programs.

Deciphering the level of genetic diversity in some aegilops species using CAAT box-derived polymorphism (CBDP) and start codon target polymorphism (SCoT) markers

BACKGROUND

Maintaining genetic diversity is of the most essential principle for a long-term conservation of plant genetic resources and could play a crucial role in their management. The genus Aegilops is one important member of wheat germplasm, and there are evidences that novel genes of this genus' species can be studied/utilized as ideal sources for the wheat cultivar improvement. The objective of this study was to dissect the genetic diversity and population structure among a set of Iranian Aegilops using two gene-based molecular markers.

METHODS AND RESULTS

This study investigated the level of genetic diversity among 157 Aegilops accessions consisting of Ae. tauschii Coss. (DD genome), Ae. crassa Boiss. (DDMM genome), and Ae. cylindrica Host. (CCDD genome) belonging to NPGBI using two sets of CBDP and SCoT markers. The SCoT and CBDP primers yielded 171 and 174 fragments, out of which 145 (90.23%) and 167 (97.66%) fragments were polymorphic, respectively. The average of polymorphism information content (PIC)/ marker index (MI)/resolving power (Rp) for SCoT and CBDP markers were 0.32/3.59/16.03 and 0.29/3.01/16.26, respectively. Results of AMOVA revealed the genetic variability within species was greater than the variation observed among them (SCoT: 88% vs. 12%; CBDP: 72% vs. 28%; SCoT + CBDP: 80% vs. 20%). Based on the information obtained from both markers, the higher level of genetic diversity was found in Ae. tauschii as compared to other species. The grouping patterns obtained by Neighbor-joining algorithms, principal coordinate analysis (PCoA), and Bayesian-model-based structure were consistent with each other and resulted in grouping all studied accessions according to their genomic constitutions.

CONCLUSION

The results of this study revealed a high level of genetic diversity among Iranian Aegilops germplasm. Moreover, SCoT and CBDP marker systems were efficient in deciphering DNA polymorphism and classification of Aegilops germplasm.

Genetic Characterization of Some Saudi Arabia's Accessions from Commiphora gileadensis Using Physio-Biochemical Parameters, Molecular Markers, DNA Barcoding Analysis and Relative Gene Expression

Commiphora gileadensis L. is a medicinal plant, known as balsam, with pharmaceutical potential for its phytochemical activities and chemical constituents. Genetic diversity is a genetic tool used in medicinal plant evolution and conservation. Three accessions from C. gileadensis were collected from three localities in Saudi Arabia (Jeddah, Jizan and Riyadh). Genetic characterization was carried out using physio-biochemical parameters, molecular markers (inter-simple sequence repeat (ISSR) and start codon targeted (SCoT)), DNA barcoding (18 S rRNA and ITS rDNA regions), relative gene expressions (phenylalanine ammonia-lyase 1 (PAL1), defensin (PR-12)) and pathogenesis-related protein (AFPRT). The results of this study showed that C. gileadensis accession C3, collected from Riyadh, had the highest content from the physio-biochemical parameters perspective, with values of 92.54 mg/g and 77.13 mg/g for total phenolic content (TPC) and total flavonoid content (TFC), respectively. Furthermore, the highest content of antioxidant enzyme activity was present in accession C3 with values of 16.87, 60.87, 35.76 and 27.98 U mg-1 for superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) (mol/min/mg FW) and ascorbate peroxidase (APX) (U mg-1 protein), respectively. The highest total number of bands and number of unique bands were 138 and 59, respectively, for the SCoT marker. The SCoT marker was the most efficient for the genetic diversity of C. gileadensis by producing the highest polymorphism (75.63%). DNA barcoding using 18 S and ITS showed the nearby Commiphora genus and clustered C. gileadensis accessions from Jeddah and Jizan in one clade and the C. gileadensis accession from Ryiadh in a separate cluster. Moreover, relative gene expression of the PAL1, defensin (PR-12) and AFPRT (PR1) genes was upregulated in the C. gileadensis accession from Ryiadh. In conclusion, ecological and environmental conditions in each locality affect the genomic expression and genetic diversity, which can help the evolution of important medicinal plants and improve breeding and conservation systems.