Morphological characterization of Iris hymenospatha and Iris histrio populations in Iran: implications for conservation and breeding.

The native populations of Iris hymenospatha and Iris histrio, two endangered bulbous species within the large Iris genus in Iridaceae, are threatened with extinction due to mining and other industrial activities in their natural habitats in Central Asia, including Iran. These species not only have a significant economic impact on the global horticultural industry due to their versatility and attractive phenotypic traits, but also have significant ecological value that necessitates their conservation. In this study, we examined the morphological and functional diversity between individuals within these two species, which exhibit high tolerance to environmental stresses. Our study examined 10 populations of I. hymenospatha and two populations of I. histrio based on bulb, flower, and leaf characteristics throughout Iran. We recognized a gradation of five different leaf shapes among I. hymenospatha populations with significant differences between some populations, including "Arak-Khomain" and "Arak-Gerdo". The "Jaro", "Natanz-Karkas", "Ardestan-Taleghan", "Arak-Rahjerd", "Arak-Gerdo", "Ganjnameh", and "Abas-Abad" populations of I. hymenospatha displayed maximal values in leaf width, stem diameter under flower, crown diameter, flower number, leaf number, and bulb diameter. The I. histrio "Velian" population had a significantly larger flower size, a longer stem length, a larger style width, a longer flowering date, and a higher plant height compared to the "Ganjnameh" population of I. histrio. Such characteristics of both species make them remarkable ornamental plants. Our study also revealed that I. hymenospatha populations grow on different soils and elevations and have the ability to adapt to different growing conditions. Given the threats they face, conservation through horticultural selection and propagation offers a viable conservation strategy for both species. This approach not only preserves the genetic diversity of these species, but also enables their further contribution to the horticultural industry.

Physiological specialization of Puccinia triticina and genome-wide association mapping provide insights into the genetics of wheat leaf rust resistance in Iran.

Leaf rust caused by Puccinia triticina Erikss. (Pt) is the most widely distributed and important wheat disease worldwide. The objective of the present study was to determine the frequency of Iranian Pt races, their virulence to key resistance genes and map quantitative trait loci (QTL) for resistance to different Pt races from 185 globally diverse wheat genotypes using a genome-wide association study (GWAS) approach. The virulence pattern of the 33 Pt isolates from various wheat-growing areas of Iran on 55 wheat differentials showed that the FKTPS and FKTTS were relatively frequent pathotypes among the 18 identified races. The weighted average frequency of virulence on the resistance genes Lrb, Lr3bg, Lr14b, Lr16, Lr24, Lr3ka, Lr11 and Lr20 were high (> 90%). However, low virulence on the resistant genes Lr2a, Lr9, Lr19, Lr25, Lr28 and Lr29 indicates that these genes are still effective against the pathogen population in Iran at present. GWAS on a panel of 185 wheat genotypes against 10 Pt races resulted into 62 significant marker-trait associations (MTAs) belonged to 34 quantitative trait loci (QTL) across 16 chromosomes. Among them, 10 QTLs on chromosomes 1A, 1B, 3B, 3D, 4A, 6D, 7A and 7D were identified as potential novel QTLs, of which four QTLs (QLr.iau-3B-2, QLr.iau-7A-2, QLr.iau-7A-3 and QLr.iau-7D-2) are more interesting, as they are associated with resistance to two or more Pt races. The known and novel QTLs associated with different Pt races found here, can be used in future wheat breeding programs to recombine different loci for durable resistance against leaf rust races.

Protein patterns and their association with photosynthetic pigment content, agronomic behavior, and origin of purslane accessions (Portulaca oleracea L.).

In this study, the proteomic, morphometric, and photosynthetic pigment data of purslane (Portulaca oleracea) accessions were combined together to show their impact on genetic variation in order to establish a relationship between protein patterns and phenotypic behavior of the plant. Seeds of 18 collected purslane accessions were cultivated based on a completely randomized design with three replicates. Before the flowering stage, the data on morphology, photosynthetic pigment content, and seed proteins were obtained. The results showed a significant difference among purslane accessions in terms of the most studied agronomic characteristics and the content of photosynthetic pigments and proteins. The cluster analysis of the 18 purslane accessions based on agronomic data, and photosynthetic pigment content, and protein pattern data produced three main clusters. Moreover, the seed protein analysis revealed that the two polymorphic protein bands of size 40 kDa (protein "a") and 30 kDa (protein "b") effectively diversified the agronomic, photosynthetic pigment, and phylogenetic relationships among the purslane accessions. Interestingly, protein "a" was produced in plants growing in low altitude areas and played a suppressive role for TDW, while protein "b" was produced in plants growing in high altitude areas and functioned as an activator agent for this trait. Overall, the outcomes of the present study indicated the presence of high genetic variability (77.6%) among the purslane accessions. These findings suggest that these proteins should be sequenced for further proteomic analyses and can be used for hybridization to generate useful recombinants in segregating generations and improve breeding varieties of P. oleracea.

In-depth genome diversity, population structure and linkage disequilibrium analysis of worldwide diverse safflower (Carthamus tinctorius L.) accessions using NGS data generated by DArTseq technology.

Safflower (Carthamus tinctorius L.) is one of the most important oilseed crops for its seed oil rich in unsaturated fatty acids. Precise utilization of diverse genetic resources is fundamental in breeding programs to improve high yield genotypes with desirable traits. In this study, for the first time we report successful application of DArTseq technology; an efficient genotyping-by-sequencing (NGS); to analysis genetic diversity and population structure of 89 safflower accessions from worldwide origins. Totally, 19,639 DArTseq markers (10,130 SilicoDArTs and 9509 SNPs) generated through DArTseq genotyping. After filtering the data, 3431 polymorphic DArTseq markers (1136 SilicoDArTs and 2295 SNPs) used for genetic diversity, population structure and linkage disequilibrium analysis in safflower genotypes. All the SilicoDArT and SNP markers showed high reproducibility and call rate. Polymorphism information content (PIC) values ranged from 0.1 to 0.5, while ≥ 0.50% of SilicoDArTs and ≥ 0.64% SNPs showed PIC values more than median. Genotypes grouping using DArTseq markers resulted in three distinct clusters. Results showed weak correlation between safflower diversity pattern and origins. Analysis of molecular variance revealed that the majority of genetic variation was attributed to the differences among varieties within cluster populations and there was no significant molecular variance between origins. However, safflower of accessions belonged to Iran, Turkey, Pakistan and India indeed appear to be genetically similar and grouped close in referred cluster, while the accessions from Near East (Afghanistan, China) being distinct. Our results were in agreement with hypothesis that safflower domesticated in somewhere west of Fertile Crescent and then expanded through Africa and Europe. Present study using a panel of globally diverse safflower accessions and large number of DArTseq markers set the stage for future analysis of safflower domestication using large germplasm from proposed domestication centers. Also, studied germplasm in this study can be used as a valuable source for future genomic studies in safflower for mapping desirable traits through genome-wide association mapping studies.

Whole-genome diversity, population structure and linkage disequilibrium analysis of globally diverse wheat genotypes using genotyping-by-sequencing DArTseq platform.

In this study, 129 wheat genotypes from globally diverse origins were genotyped using DArTseq (SilicoDArT and SNP) markers. After filtering markers for quality-filtering, 14,270 SilicoDArTs and 6484 SNPs were retained and used for genetic diversity, population structure and linkage disequilibrium analyses. The highest number of SilicoDArT and SNP markers mapped on genome A and B compared to genome D. In both marker types, polymorphism information content (PIC) values ranged from 0.1 to 0.5, while > 0.80% of SilicoDArTs and > 0.44% SNPs showed PIC value more than median (0.25%). Un-weighted Neighbor Joining cluster analysis and Bayesian-based model population structure grouped wheat genotypes into three and four clusters, respectively. Principal component analysis and discriminant analysis of principal component results showed highly match with cluster and population structure analysis. Linkage disequilibrium (LD) was more extensive in both marker types, while graphical display of LD decay for both marker types showed that LD declined in the region close to 15 kbp, where r 2-values corresponded to r 2 = 0.16. Overall, our genetic diversity analysis showed high level of variation in studied wheat genotypes, even though there was no relationship between wheat grouping and origins. This might be attributed to admixture level that occurred during long-term natural selection of wheat genotypes in different parts of the world. Highly diverse wheat genotypes used in this study may possess unique genes and are useful sources in breeding programs to improve grain yield and quality.

Genetic variation and interrelationships of agronomic characteristics in durum wheat under two constructing water regimes

This work aimed to study the grain yield components and plant characteristics related to grain yield. Twenty-four durum wheat genotypes from the ICARDA durum wheat breeding program were grown during 2006-2007 under rainfed and irrigated conditions using a complete randomized block design with three replicate in west of Iran. Correlation and path analysis were carried out. Results showed that there was strong positive association of grain yield with the number of seed/spike, biomass and harvest index. Grain yield was negatively associated with spike length and plant height in different moisture conditions. Comparatively, high genetic variation was found in grain yield and other characteristics. Hierarchical cluster analysis was used as a tool to classify the genotypes according to their grain yield ability under optimum and drought stress conditions. Among the genotypes, one of three groups of genotypes were characterized by high grain yield in optimum and drought stress conditions. These genotypes could be used as source of germplasm for breeding for drought tolerance.

Validation of EST-derived STS markers localized on Qfhs.ndsu-3BS for Fusarium head blight resistance in wheat using a 'Wangshuibai' derived population.

A few EST-derived STS markers localized on Qfhs.ndsu-3BS, a major QTL for resistance to Fusarium head blight (FHB) in wheat, have been previously identified in the 'Sumai 3'/'Stoa' population. In this study, we used a 'Wangshuibai' (resistant) /'Seri82' (susceptible) derived population, linkage group, QTL, and quantitative gene expression analysis to assess the genetic background dependence and stability of the EST-derived STS markers for use in marker aided selection to improve FHB resistance in wheat. Based on our results, a QTL in the map interval of Xsts3B-138_1-Xgwm493 on chromosome 3BS was detected for FHB resistance, which accounted for up to 16% of the phenotypic variation. BLASTN analysis indicated that Xsts3B-138_1 sequence had significant similarity with the resistance gene analogue. Real-time quantitative PCR showed that the relative expression of Xsts3B-138_1 in 'Wangshuibai' at 96 h after inoculation was 2.6 times higher than 'Seri82'. Our results underlined that EST-derived STS3B-138 markers could be predominantly used in marker aided selection to improve FHB resistance in wheat.