Search Results (425)

The population size of black poplar (Populus nigra L.), once an important part of floodplain forests in the Czech Republic, has greatly declined due to human activity. In this study, we applied microsatellite (SSR) markers to identify species and assess genetic diversity, with the aim of supporting conservation of this endangered species. A total of 378 poplar trees were analyzed following field surveys. Five diagnostic SSR markers with species-specific alleles for P. deltoides Bartr. ex Marsh. enabled the identification of 39 interspecific hybrids, which were distinguished from native P. nigra. Thirteen SSR loci were used to evaluate genetic diversity among confirmed P. nigra individuals. The results revealed high genetic variation, with 66% of pairwise genotype comparisons differing at all loci. After excluding 45 genetically similar individuals, 292 genetically verified and polymorphic P. nigra trees were selected as potential sources of reproductive material. Genetic differentiation (Fst) was highest between P. nigra and P. deltoides (0.27), and lowest between reference Populus ×euroamericana clones and detected hybrid poplars (0.05) from natural localities. Distinct genetic structures were identified among P. nigra, P. deltoides, and hybrid individuals. These findings provide essential data for the protection, reproduction, and planting of black poplar. Full article

This review explores the accumulated research and technological potential of Saccharomyces eubayanus, a cold-tolerant wild yeast first isolated in 1997 from the Andean-Patagonian forests of Argentina but formally described in 2011. S. eubayanus has garnered attention since it was identified as the missing parent of the lager-beer yeast S. pastorianus and because it demonstrated valuable fermentative skills and an unexpected large intraspecific genetic diversity. The article recapitulates the characterization of the fermentative capacity of the type strain, as well as its ability to produce distinctive aromatic profiles compared to conventional lager yeasts. We discuss how these features have driven the development of improved strains through experimental evolution and the generation of interspecific hybrids with S. cerevisiae exhibiting appropriate fermentation performance and a broad aromatic diversity. We also aim to address the applications of S. eubayanus in commercial brewing, especially in the craft beer industry, and highlight its potential to add value and/or regional identity to beer through novel flavor profiles. Finally, the review outlines the main challenges limiting large-scale implementation, emphasizing the importance of continued research into strain development and brewing strategies to fully harness the potential of this wild yeast species. Full article

Accurate normalization is crucial for reliable gene expression quantification and depends on stably expressed housekeeping genes (HKGs) as internal controls. However, HKGs expression varies with developmental stage, tissue type, and treatments, potentially introducing bias and compromising data accuracy. Thus, validating candidate reference genes under defined conditions is essential. Reynoutria, also known as giant Asian knotweeds, is a Polygonaceae family genus of several medicinal plants producing a diverse array of specialized metabolites of pharmacological interest. Outside their native range, these plants are also noxious invasive weeds, causing significant environmental and economic threats. Research on stable reference genes in these species is limited, with a primary focus on R. japonica. To enable accurate gene expression analysis related to specialized metabolism and natural product biosynthesis, we aimed to identify the most stable reference genes across the most common species: R. japonica Houtt., R. sachalinensis (F. Schmidt) Nakai, and their hybrid—R. × bohemica Chrtek & Chrtková. In this study, we evaluated twelve candidate HKGs (ACT, TUA, TUB, GAPDH, EF-1γ, UBQ, UBC, 60SrRNA, eIF6A, SKD1, YLS8, and NDUFA13) across three tissue types (rhizomes, leaves, and flowers) from three Reynoutria species sampled at peak flowering. Primer specificity and amplification efficiency were confirmed through standard-curve analysis. We assessed expression stability using ΔCt, geNorm, NormFinder, and BestKeeper, and generated comprehensive rankings with RefFinder. Our integrated analysis revealed organ- and species-dependent stability differences, yet identified up to three reference genes suitable for interspecific normalization in Reynoutria. This represents the first systematic, comparative validation of HKGs across closely related knotweed species, providing a robust foundation for future transcriptomic and functional studies of their specialized metabolism and other biological processes. Full article

With the increasing severity of forest pest problems, breeding insect-resistant varieties has become a crucial task for the sustainable development of forestry. The highly insect-resistant triploid Populus line Pb29, genetically modified with BtCry1Ac, served as the maternal parent in controlled hybridization with three paternal Populus cultivars. Hybrid progenies were obtained through embryo rescue and tissue culture. Results showed that 4 °C storage was favorable for pollen preservation, with 84K poplar exhibiting superior pollen viability and embryo germination rates. All progenies displayed significantly lower seedling height and ground diameter growth than the maternal parent (p < 0.05), with some showing leaf shape and branching variations. Among the three crosses, the 84K-sired progeny exhibited the best growth performance but the highest variability. PCR analysis confirmed stable inheritance of the BtCry1Ac and Kan genes from Pb29, showing tight linkage. Progenies carrying BtCry1Ac exhibited detectable gene transcription and toxic protein accumulation, though expression levels varied due to copy number, insertion sites, and potential co-suppression effects. Ploidy analysis suggested all hybrids were aneuploid, with lower survival rates than the maternal parent. Insect-feeding assays confirmed high resistance in all BtCry1Ac-inheriting progenies, with an average larval mortality rate of 97.03%. Mortality rates and death indices significantly correlated with transcript abundance and toxin protein levels. These results demonstrate that BtCry1Ac insect resistance is stably inherited through hybridization. Transgene expression appears co-modulated by copy number, insertion sites, and ploidy status. Simultaneously, it was found that the aneuploid progeny derived from triploid hybridization exhibited growth disadvantages. This provides an important basis for subsequent poplar improvement breeding. Full article

Somatic hybridization represents a powerful tool for generating novel chemotypes with enhanced biosynthetic capabilities. This study provides the first comprehensive phytochemical characterization of interspecific somatic hybrids between Gentiana cruciata L. and Gentiana tibetica King ex Hook.f., two medicinally important yet regionally rare gentians. A total of 107 compounds were detected using UHPLC-DAD-ESI-MS³, of which 31 were identified as metabolites across eight phytochemical classes. Comparative profiling revealed that all hybrids retained a conserved core of iridoids and secoiridoids while integrating lineage-specific compounds and producing hybrid-specific metabolites not detected in either parent. Despite inheriting plastids from G. tibetica, hierarchical clustering showed that the phytochemical profiles of hybrid lines were more similar to G. cruciata, the donor of the nuclear genome. Quantitative analysis of the major secoiridoids, such as gentiopicroside, swertiamarin, and sweroside, demonstrated that several hybrid lines, particularly F30A-5 and F30A-6, matched or surpassed the biosynthetic output of G. tibetica, the more productive parent. These lines also exhibited elevated antioxidant capacity, underscoring their phytochemical and functional potential. Altogether, our findings show that somatic hybridization not only preserves but may amplify the secondary metabolite capacity of the parental genotypes, offering a viable platform for sustainable in vitro production of pharmacologically relevant secoiridoids. Full article

Diploid Vaccinium fuscatum is a wild blueberry species with a low chilling requirement, an evergreen growth habit, and soil adaptability to southeast US growing regions. Regardless of its potential to improve the abiotic and biotic resilience of cultivated blueberries, this species has rarely been used for blueberry breeding. One hurdle is the ploidy barrier between diploid V. fuscatum and tetraploid cultivated highbush blueberries. To overcome the ploidy barrier, vegetative shoots micro-propagated from one genotype of V. fuscatum, selected because it grew vigorously in vitro and two southern highbush cultivars, ‘Emerald’ and ‘Rebel,’ were treated with colchicine. While shoot regeneration was severely repressed in ‘Emerald’ and ‘Rebel,’ shoot production from the V. fuscatum clone was not compromised at either 500 µM or 5000 µM colchicine concentrations. Due to the high number of shoots produced in vitro via the V. fuscatum clone shoots of this clone that had an enlarged stem diameter in vitro were subjected to flow cytometer analysis to screen for induced polyploidy. Sixteen synthetic tetraploid V. fuscatum, one synthetic octoploid ‘Emerald,’ and three synthetic octoploid ‘Rebel’ were identified. Growth rates of the polyploid-induced mutants were reduced compared to their respective wildtype controls. The leaf width and length of synthetic tetraploid V. fuscatum and synthetic octoploid ‘Emerald’ was increased compared to the wildtypes, whereas the leaf width and length of synthetic octoploid ‘Rebel’ were reduced compared to the wildtype controls. Significant increases in stem thickness and stomata guard cell length were found in the polyploidy-induced mutant lines compared to the wildtypes. In the meantime, stomata density was reduced in the mutant lines. These morphological changes may improve drought tolerance and photosynthesis in these mutant lines. Synthetic tetraploid V. fuscatum can be used for interspecific hybridization with highbush blueberries to expand the genetic base of cultivated blueberries. Full article

Climate extremes threaten the resilience of Eucalyptus plantations, yet hybridization with drought-tolerant species may enhance stress tolerance. This study analyzed xylem anatomical and functional drought responses in commercial Eucalyptus grandis (GG) clones and hybrids: E. grandis × camaldulensis (GC), E. grandis × tereticornis (GT), and E. grandis × urophylla (GU1, GU2). We evaluated vessel traits (water transport), fibers (mechanical support), and wood density (D) in stems and branches. Theoretical stem hydraulic conductivity (k_Stheo), vessel lumen fraction (F), vessel composition (S), and associations with previous hydraulic and growth data were assessed. While general drought responses occurred, GC had the most distinct xylem profile. This may explain it having the highest performance in different irrigation conditions. Red gum hybrids (GC, GT) maintained k_Stheo under drought, with stable F and a narrower vessel size, especially in branches. Conversely, GG and GU2 reduced F and S; and stem k_Stheo declined for a similar F in these clones, indicating vascular reconfiguration aligning the stem with the branch xylem. Almost all clones increased D under drought in any organ, with the highest increase in red gum hybrids. These results reveal diverse anatomical adjustments to drought among clones, partially explaining their growth responses. Full article

Climate change is jeopardizing global food security, with at least 713 million people facing hunger. To face this challenge, legumes as common beans could offer a nature-based solution, sourcing nutrients and dietary fiber, especially for rural communities in Latin America and Africa. However, since common beans are generally heat and drought susceptible, it is imperative to speed up their molecular introgressive adaptive breeding so that they can be cultivated in regions affected by extreme weather. Therefore, this study aimed to couple an advanced panel of common bean (Phaseolus vulgaris L.) × tolerant Tepary bean (P. acutifolius A. Gray) interspecific lines with Bayesian regression algorithms to forecast adaptation to the humid and dry sub-regions at the Caribbean coast of Colombia, where the common bean typically exhibits maladaptation to extreme heat waves. A total of 87 advanced lines with hybrid ancestries were successfully bred, surpassing the interspecific incompatibilities. This hybrid panel was genotyped by sequencing (GBS), leading to the discovery of 15,645 single-nucleotide polymorphism (SNP) markers. Three yield components (yield per plant, and number of seeds and pods) and two biomass variables (vegetative and seed biomass) were recorded for each genotype and inputted in several Bayesian regression models to identify the top genotypes with the best genetic breeding values across three localities on the Colombian coast. We comparatively analyzed several regression approaches, and the model with the best performance for all traits and localities was BayesC. Also, we compared the utilization of all markers and only those determined as associated by a priori genome-wide association studies (GWAS) models. Better prediction ability with the complete SNP set was indicative of missing heritability as part of GWAS reconstructions. Furthermore, optimal SNP sets per trait and locality were determined as per the top 500 most explicative markers according to their β regression effects. These 500 SNPs, on average, overlapped in 5.24% across localities, which reinforced the locality-dependent nature of polygenic adaptation. Finally, we retrieved the genomic estimated breeding values (GEBVs) and selected the top 10 genotypes for each trait and locality as part of a recommendation scheme targeting narrow adaption in the Caribbean. After validation in field conditions and for screening stability, candidate genotypes and SNPs may be used in further introgressive breeding cycles for adaptation. Full article

The review summarizes the historical and current research on perennial grain breeding in Russia within the context of growing global interest in perennial crops. N.V. Tsitsin’s pioneering work in the 1930s produced the first wheat–wheatgrass amphiploids, which demonstrated the capacity to regrow after harvest and survive for 2–3 years. Subsequent research at the Main Botanical Garden in Moscow focused on characterizing Tsitsin’s material, selecting superior germplasm, and expanding genetic diversity through new cycles of hybridization and selection. This work led to the development of a new crop species, Trititrigia, and the release of cultivar ‘Pamyati Lyubimovoy’ in 2020, designed for dual-purpose production of high-quality grain and green biomass. Intermediate wheatgrass (Thinopyrum intermedium) is native to Russia, where several forage cultivars have been released and cultivated. Two large-grain cultivars (Sova and Filin) were developed from populations provided by the Land Institute and are now grown by farmers. Perennial rye was developed through interspecific crosses between Secale cereale and S. montanum, demonstrating persistence for 2–3 years with high biomass production and grain yields of 1.5–2.0 t/ha. Hybridization between Sorghum bicolor and S. halepense resulted in two released cultivars of perennial sorghum used primarily for forage production under arid conditions. Russia’s agroclimatic diversity in agricultural production systems provides significant opportunities for perennial crop development. The broader scientific and practical implications of perennial crops in Russia extend to climate-resilient, sustainable agriculture and international cooperation in this emerging field. Full article

Grapevine breeding programs face difficulties in preserving germplasm, especially from species and interspecific hybrids, since most collections are maintained in the field and exposed to biotic and abiotic stress, which can lead to material loss. The Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) Grapevine Breeding Program faces similar challenges, limiting studies on hybrids resistant to the nematode Pratylenchus brachyurus and downy mildew (Plasmopara viticola), which are valuable for genetic improvement. This study aimed to implement in vitro conservation under minimal growth conditions for interspecific hybrids of Vitis spp. from the UENF program. The protocol followed a completely randomized design in a 2 × 2 × 3 factorial scheme: two hybrids (CH1.2 and CH1.3), two temperatures (18 ± 1 °C and 27 ± 2 °C), and three sucrose concentrations (10, 20, and 30 g L⁻¹), over 180 days of in vitro culture. The results showed that conservation of the UENF hybrids is feasible using nodal segments as explants, at 18 ± 2 °C and 10 g L⁻¹ of sucrose, for up to four months. This protocol may also be applied to other Vitis spp., contributing to the preservation and continued study of valuable germplasm. Full article

A combination of high potential productivity and ecological stability is essential for current cultivars, which is achievable by breeding. Interspecific/intergeneric hybridization remains a key approach to producing new high-yielding and resistant cultivars. Interspecific reproductive barriers (IRBs) appear in the interaction between the pollen and pistil of interspecific/intergeneric hybrids. The mechanisms underlying these hybridization barriers are to a considerable degree unknown. The pollen–pistil interaction is decisive because the pollen of distantly related plant species either is not recognized by stigma cells or is recognized as foreign, preventing pollen tube (PT) germination and/or penetration into the stigma/style/ovary. This review mainly focuses on (1) the pollen–pistil system; (2) IRB classification; (3) similarity and differences in the function of self-incompatibility (SI) barriers and IRBs; and (4) physiological and biochemical control of IRBs and their overcoming. The main goal is to illuminate the physiological, biochemical, and molecular mechanisms underlying the growth arrest of incompatible PTs and their death. In general, this review consolidates the current understanding of the interaction of the male gametophyte with the sporophyte tissues of the pistil and outlines future research directions in the area of plant reproductive biology. Full article

The undertaking of distant hybridization holds paramount significance for the innovation of tea germplasm resources and the cultivation of superior, specialized tea varieties. However, challenges manifest during the process of tea plant distant hybridization breeding, with reproductive barriers impeding the successful acquisition of hybrid progeny; the precise stages at which these barriers occur remain unclear. In this study, utilizing Camellia sinensis cv. Jinxuan as the maternal parent, as well as C. gymnogyna Chang and C. sinensis cv. Yinghong No.9 as the paternal parents, interspecific distant hybridization (DH) and intraspecific hybridization (IH) were conducted. The investigation involved the observation of pollen germination and pollen tube behavior on the stigma, the scrutiny of the developmental dynamics of the ovary post-hybridization, and the examination of the stages and reasons for reproductive disorders during tea tree distant hybridization. The findings indicate that both IH and DH exhibit pre-fertilization barriers. The pre-embryonic development of hybrids obtained from DH is normal, but there is a significant fruit drop during the stage of fruit development. The germination rate of mature seeds obtained from DH is low, and there are pronounced post-fertilization disorders, which are the primary reasons for the difficulty in achieving successful tea plant distant hybridization. An analysis of the genetic variation in phenotypes and chemical components in the progeny after distant hybridization revealed widespread variation and rich genetic diversity. The identification of progeny with a high amino acid and caffeine content holds promise for future production and breeding, providing valuable theoretical references for the selection of parents in the creation of low-caffeine-content tea germplasm resources. Full article

Leaves are the most ubiquitous plant organs, whose macrostructures exhibit close correlations with environmental factors while simultaneously reflecting inherent genetic and evolutionary patterns. These characteristics render them highly significant for plant taxonomy, ecology, and related disciplines. Therefore, this study presents the first comprehensive evaluation of Malus leaf macrostructures for infraspecific classification. By establishing a trait-screening system, we conducted a numerical taxonomic analysis of leaf phenotypic variation across 73 Malus germplasm (34 species and 39 cultivars). Through ancestor-inclined distribution characteristic analysis, we investigated phylogenetic relationships at both the genus level and infraspecific ranks within Malus. A total of 21 leaf phenotypic traits were selected from 50 candidate traits based on the following criteria: high diversity, abundance, and evenness (D ≥ 0.50, H ≥ 0.80, and E ≥ 0.60); significant intraspecific uniformity and interspecific distinctness ($\overline{CV}$ ≤ 10% and $CV$ ≥ 15%). Notably, the selected traits with low intraspecific variability ($\overline{CV}$ ≤ 10%) exhibit environmental robustness, likely reflecting low phenotypic plasticity of these specific traits under varying conditions. This stability enhances their taxonomic utility. It was found that the highest ancestor-inclined distribution probability reached 90% for 10 traceable cultivars, demonstrating reliable breeding lines. Based on morphological evidence, there was a highly significant correlation between the evolutionary orders of (Sect. Docyniopsis → Sect. Sorbomalus → Sect. Malus) and group/sub-groups (B₁ → B₂ → A). This study demonstrates that phenotypic variation in leaf macrostructures can effectively explore the affinities among Malus germplasm, exhibiting taxonomic significance at the infraspecific level, thereby providing references for variety selection. However, hybrid offspring may exhibit mixed parental characteristics, leading to blurred species boundaries. And convergent evolution may create false homologies, potentially misleading morphology-based taxonomic inferences. The inferred taxonomic relationships present certain limitations that warrant further investigation. Full article

Pummelo (Citrus maxima) is an ancestral species that has given rise to several major citrus varieties, such as sweet orange (C. x aurantium var. sinensis) and grapefruit (C. x aurantium var. paradisi). This species is also cultivated and its fruit consumed, particularly in Asia. Over the course of evolution, the allogamous reproduction of pummelos and the absence of asexual multiplication have contributed to its diversification. To assess its phenotypic diversity and the chemical composition of leaf and peel essential oils, genetic analysis using DNA markers is an essential prerequisite to ensure the identity and if varieties belong to this species. Fifty-eight accessions classified as grapefruits or pummelos were analyzed using 42 SSRs, 4 Indels, and 36 SNP markers. Based on the allelic composition of these markers, 20 cultivars were detected belonging to pummelos, 18 cultivars to grapefruits, and 11 were interspecific hybrids. The grapefruit inter-cultivar SSR diversity is null. The genetic origin of five interspecific hybrids is elucidated. The level of phenotypic diversity and of essential oil composition corroborate the modes of diversification, with high levels for those resulting from crosses and very low levels for the group of grapefruit mutants. Only the characteristics of breeding selection (pulp color, acidity and aspermia) are variable in grapefruits. In the composition of leaf essential oils (LEOs), nine profiles were detected in grapefruits based on variations in six compounds (neral, geranial, β-phellandrene, γ-terpinene, (E)-β-ocimene, and β-pinene). The seven interspecific hybrids involving pummelo as one parent show particular LEO profiles but without specific compounds, with the exception of p-cymenene which is present only in Wheeny. The diversity of peel essential oils in pummelos is lower, but variations in γ-terpinene, β-pinene, limonene, and myrcene make it possible to define seven profiles. With genetic verification the chemical and phenotypic diversity of the two species, pummelo and grapefruit, revealed in this study can be used as a reference for behavior in a specific environment. Full article

Expanding genetic variability of cultivated cotton (Gossypium hirsutum) is essential for improving fiber quality and pest resistance. This study synthesized allotetraploids through interspecific hybridization between G. herbaceum (A₁) and G. nelsonii (G₃). Upon chromosome doubling using 0.2% colchicine, fertile F₁C allotetraploids (A₁A₁G₃G₃) were developed. Cytogenetic analysis confirmed chromosome stability of synthetic allotetraploids, and 74 polymorphic SSR markers verified hybridity and parental contributions. The F₁C hybrids exhibited enhanced resistance to cotton aphids (Aphis gossypii) and whiteflies (Aleyrodidae), with respective infestation rates of 5.2–5.6% and 5.4–5.8%, lower than those of G. hirsutum cv. Ravnak-1 (22.1% and 23.9%). Superior fiber length (25.0–26.0 mm) was observed in complex hybrids and backcross progeny, confirming the potential for trait introgression into elite cultivars. Phylogenetic analysis based on SSR data clearly differentiated G. herbaceum from Australian wild species, demonstrating successful bridging of divergent genomes. The F₁C hybrids consistently expressed dominant G. nelsonii-derived traits regardless of the hybridization direction and clustered phylogenetically closer to the wild parent. These synthetic allotetraploids could broaden the genetic base of G. hirsutum, addressing cultivation constraints through improved biotic stress resilience and fiber quality traits. The study establishes a robust framework for utilizing wild Gossypium species to overcome genetic bottlenecks in conventional cotton breeding programs. Full article