Aghafakhr Mirlohi

Heat stress (HS) significantly impedes wheat production, making the development of heat-tolerant cultivars increasingly essential in the context of climate change. This study evaluated 153 elite spring wheat ( Triticum aestivum L.) genotypes from the Wheat Association Mapping Initiative (WAMI) panel and three controls in field trials conducted during the 2020–2021 and 2021–2022 growing seasons at the Isfahan University of Technology research farm, Iran. Two sowing dates (SD; fall and spring) under full irrigation were employed to replicate HS conditions, with spring SD simulating terminal HS and reflecting regional farming practices. HS reduced days to flowering (DF), anthesis (DA), and maturity (DM) by 36–45%, shortened the grain-filling period (GFP), and decreased grain yield (GY) by ~25%, while key flour-quality traits (e.g., Zeleny index and grain hardness) remained stable under both SDs. Considerable genotypic variability was observed in both agronomic and quality traits. Stress tolerance and sensitivity indices (STI, MP, YSI, and HSI) were used to classify genotypes, with HSI identified as the most effective index due to its strong association with yield performance under HS. Several WAMI lines (e.g., 029, 123, 104, 067, and 139) demonstrated high yield potential combined with robust heat tolerance, as evidenced by their reduced yield loss under HS. These findings highlight the value of the WAMI panel for identifying heat-resilient wheat genotypes and providing critical insights for breeding programs targeting improved wheat performance under terminal HS and water-limited environments.

Synthetic hexaploid lines are proposed as high-potential germplasm for improving bread wheat by introducing new genes (biotic and abiotic stresses) lost during common wheat evolution. A panel of 99 synthetic and common wheat was studied for quality and grain-related traits and drought tolerance under two different moisture conditions (water stress and normal) during two growing seasons. Results indicated different variations for most traits suggesting that the synthetic hexaploid wheat-derived lines (SHW-DL) panel contains valuable genes for drought tolerance improvement of wheat. Drought stress reduced morphological traits and production but increased protein (Pro), rapid mix test (RMT), and solvent retention capacity (SRC) traits. Synthetic wheat lines were superior with higher grain yield, glutenin, damaged starch, available pentosane, overall water holding capacity, and gluten strength (glutenin and gliadin strength) compared to common wheat making them more suitable for bread-baking. The results showed that solvent retention capacity had a strong capacity to differentiate the quality of wheat genotypes. Correlation analysis indicated that genetic improvement for high-yielding varieties can be achieved by producing more damaged starch, higher water absorption, hardness, and lower gluten strength, and zeleny (ZEL). Selection of superior genotypes using univariate and multivariate methods will be discussed.

Epichloë species are systemic, often seed-transmissible symbionts (endophytes) of cool-season grasses (Poaceae subfam. Poöideae) that produce up to four classes of bioprotective alkaloids. Whereas haploid Epichloë species may reproduce sexually and transmit between host plants (horizontally), many Epichloë species are polyploid hybrids that are exclusively transmitted via seeds (vertically). Therefore, the generation of, and selection on, chemotypic (alkaloid) profiles and diversity should differ between haploids and hybrids. We undertook a genome-level analysis of haploids and polyploid hybrids, emphasizing hybrids that produce lolines, which are potent broad-spectrum anti-invertebrate alkaloids that can accumulate to levels up to 2% of plant dry mass. Prior phylogenetic analysis had indicated that loline alkaloid gene clusters (LOL) in many hybrids are from the haploid species Epichloë bromicola, but no LOL-containing E. bromicola strains were previously identified. We discovered LOL-containing E. bromicola from host grasses Bromus tomentellus and Melica persica in a Mediterranean-climate region (MCR) in Isfahan Province, Iran, and from Thinopyrum intermedium in Poland. The isolates from B. tomentellus and M. persica were closely related and had nearly identical alkaloid gene profiles, and their LOL clusters were most closely related to those of several Epichloë hybrids. In contrast, several LOL genes in the isolate from T. intermedium were phylogenetically more basal in genus Epichloë, indicating trans-species polymorphism. While identifying likely hybrid ancestors, this study also revealed novel host ranges in central Iran, with the first observation of E. bromicola in host tribe Meliceae and of Epichloë festucae in host tribe Bromeae. We discuss the possibility that MCRs may be hotspots for diversification of grass-Epichloë symbioses via extended host ranges and interspecific hybridization of the symbionts.

Background: Wheat grain protein, zinc (Zn), and iron (Fe) content are important wheat qualities crucial for human nutrition and health worldwide. Increasing these three components simultaneously in wheat grains by a single gene came into the picture through NAM-B1 cloning. NAM-B1 gene and its association with the mentioned grain quality traits have been primarily studied in common and durum wheat and their progenitors T. dicoccum and T. dicoccoides. Method: In the present study, for the first time, 38 wheat accessions comprising ten hexaploids from five species and 28 tetraploids from nine species were evaluated in the field for two consecutive years. Additionally, the 582 first nucleotides of the NAM-B1 gene were examined. Result: The NAM-B1 gene was present in 21 tetraploids and five hexaploid accessions. Seven tetraploid accessions contained the wild-type allele (five T. dicoccum, one T. dicoccoides, and one T. ispahanicum) and fourteen the mutated allele with a ‘T’ insertion at position 11 in the open reading frame, causing a frameshift. In hexaploid wheat comprising the gene, only one accession of T. spelta contained the wild-type allele, and the rest resembled the insertion mutated type. In the two-year field experiment, eight accessions with the wild-type NAM-B1 allele had significantly higher protein, Zn and Fe grain content when compared to indel-type accessions. Additionally, these accessions exhibited a lower mean for seed-filling duration than all other accessions containing indel-type alleles. In terms of grain yield, 1,000-kernel weight, kernel diameter, and kernel length, T. dicoccum accessions having wild-type alleles were similar to the indel-type accessions over two years of evaluation. Conclusion: These findings further support the possibility of simultaneous improvement of wheat grain protein, Zn, and Fe content by a single gene crucial for human nutrition and health worldwide.

Flaxseed (Linum usitatissimum L.) is a plant with a wide range of medicinal, health, nutritional, and industrial uses. This study assessed the genetic potential of yellow and brown seeds in thirty F4 families under different water conditions concerning seed yield, oil, protein, fiber, mucilage, and lignans content. Water stress negatively affected seed and oil yield, while it positively affected mucilage, protein, lignans, and fiber content. The total mean comparison showed that under normal moisture conditions, seed yield (209.87 g/m²) and most quality traits, including oil (30.97%), secoisolariciresinol diglucoside (13.89 mg/g), amino acids such as arginine (1.17%) and histidine (1.95%), and mucilage (9.57 g/100 g) were higher in yellow-seeded genotypes than the brown ones ((188.78 g/m²), (30.10%), (11.66 mg/g), (0.62%), (1.87%), and (9.35 g/100 g), respectively). Under water stress conditions, brown-seeded genotypes had a higher amount of fiber (16.74%), seed yield (140.04 g/m²), protein (239.02 mg. g⁻¹), methionine (5.04%), and secondary metabolites such as secoisolariciresinol diglucoside (17.09 mg/g), while their amounts in families with yellow seeds were 14.79%, 117.33 g/m², 217.12 mg. g⁻¹, 4.34%, and 13.98 mg/g, respectively. Based on the intended food goals, different seed color genotypes may be appropriate for cultivation under different moisture environments.

This study aimed to examine the reaction of several wheat species with different ploidy levels to foliar application of zinc (Zn) and iron (Fe) under different water regimes. Thirty-five wheat genotypes, including nineteen tetraploids from ten different species, ten hexaploids from five species, and six diploids from three species, were evaluated in the field over two moisture regimes with the following four treatments: control, foliar Zn application, foliar Fe application, and foliar Zn + Fe application. The experiments were conducted according to a split-plot scheme in a randomized complete block design with two replications in each moisture regime. Water stress negatively affected all measured traits, except grain Zn and Fe content. Combined foliar application of Zn + Fe significantly increased yield and alleviated yield reduction caused by water stress. Applying Zn and Fe significantly increased both micronutrient content in grains under both moisture conditions. Tetra and hexaploid species yielded nearly four times as much grain as unimproved diploid species and were less affected by water stress. All ploidy levels responded almost similarly to Zn and Fe treatments, with the combined application being as effective as each element separately. The highest yield increase in response to combined application of Zn + Fe under the two moisture conditions and the highest grain Zn content in response to Zn application under water stress was observed in hexaploid wheat. Combined foliar application of Zn and Fe increases grain Zn and Fe and alleviates water stress's adverse effects on all wheat ploidy levels, making biofortification cost-effective.

Emmer wheat has not been improved but is a valuable gene source for improving durum (Triticum turgidum ssp. durum). Conversely, durum is less looked upon for emmer (T. turgidum ssp. dicoccum) improvement. This study examined the possibility of concurrently improving the two species by crossing eight durum cultivars with four emmer local varieties in a half‐diallel fashion in two consecutive years. Also, emmer and two durum genotypes were reciprocally backcrossed, and their BC₁F₁ progeny were field‐evaluated during the wheat cropping season (November–June) at the Isfahan University of Technology research farm (32°32′ N, 51°23′ E). The results showed that durum wheat had a considerable effect on the grain yield (GY), kernel diameter, 1,000‐kernel weight (TKW), and test weight of F₁ hybrids, whereas emmer contributed more to increasing the grain protein content (GPC), kernel length, and plant height (PH). A similar pattern was observed for BC₁F₁ hybrids from the two recurrent durum parents. The GPC was reduced with recurrent durum parents in the backcrosses compared with emmer, but was still higher than in both durum parents. In the backcrosses with the recurrent emmer parent, GY and TKW were higher than those of emmer but only slightly lower than those of the durum parents. The PH was strongly influenced by emmer in all crosses, though the lodging was significantly reduced compared with emmer, possibly through obtaining stronger stems from durum. These findings suggest the possibility of combining desirable genes from the two species and their concurrent improvement in a single breeding program.