Modern Cultivars Research Articles

Breeding of Modern Rose Cultivars Decreases the Content of Important Biochemical Compounds in Rose Hips.

This study aimed to determine the content and composition of bioactive compounds in autochthonous rose hips (R. pendulina, R. spinosissima, and R. gallica) and to compare them with the content of bioactive compounds in some cultivars ('Harstad', 'Bourgogne', 'Mount Everest', 'Poppius', 'Fruhlingsduft', 'Single Cherry', 'Fruhlingsmorgen', 'Violacea', and 'Splendens') derived from these main species. Due to insufficient information on how bioactive compound content changes when crossing roses, this study also sought to ascertain whether modern rose hip cultivars are still a sufficiently rich source of bioactive compounds and could, therefore, be potentially used as a functional food. All material was collected in the Arboretum Volčji Potok (Slovenia). The ascorbic acid content was highest in the 'Harstad' cultivar (12.79 g/kg FW), and the total organic acid content varied from 1.57 g/kg FW (R. spinosissima) to 34.39 g/kg FW ('Harstad'). Of all the carotenoids analyzed, only lycopene and β-carotene were present in all the samples. The total carotenoid content was highest in the 'Fruhlingsmorgen' cultivar (100.84 mg/kg FW), derived from R. spinosissima, and lowest in the main species, R. spinosissima (9.26 mg/kg FW). It can be concluded, therefore, that the content of bioactive compounds in rose hips of modern cultivars is generally lower than in rose hips of old cultivars and original species included in this study. The research results confirm that modern breeding strategies are mainly focused on goals such as abundant flowering and resistance to diseases and pests and not so much on the content of bioactive compounds.

Reevaluation of the degree day base 60°F concept in US cotton (Gossypium hirsutumL.) production

AbstractCotton (Gossypium hirsutumL.) management decisions to abet early growth, fruit set, boll maturation, and harvest preparation are often facilitated by prediction of the date when critical developmental stages are reached. In the United States, growing degree days calculated with a base 60°F (DD60s) are commonly used to predict cotton development. Observations suggest development of modern cultivars differs from previously established guidelines. The objectives were to (1) reevaluate DD60s required for an early, mid‐maturing and late maturing cultivar to reach key growth stages across the US Cotton Belt; and (2) determine if predictions of growth stages are strengthened by optimizing base temperature or including an upper threshold by growth stage. During 2018 and 2019, 22 field trials were established in 10 states. Plant growth stages were monitored weekly and air temperature was computed from interpolated surface observations weighted by a physical, geographic model. Observed DD60s to reach growth stages varied slightly by cultivar and region (≤85 DD60s and ≤130 DD60s, respectively). Required DD60s to reach growth stages exceeded most published ranges. Optimization of base temperature and inclusion of an upper threshold by growth stage did not substantially decrease errors in predicting date of growth stage occurrence. The DD55 and DD55 with an upper threshold of 86°F calculations resulted in slightly lower errors in predicting date of growth stage occurrence than the DD60 calculation. Although guidelines should be updated, it is unlikely slight modification in base temperature or upper thresholds will drastically increase the predictive ability over the DD60 calculation.

Genetic gain of grain yield and quality in bread wheat cultivars representing 40 years of breeding in Morocco

Background. Knowledge about the genetic gain for fundamental traits over time is essential for a critical assessment and improvement of breeding programs, especially regarding staple crops like bread wheat.Materials and methods. To estimate the genetic gain in bread wheat breeding in Morocco, grain yield (GY) and grain protein content (GPC) data were collected from 12 multi-environment field trials for 20 bread wheat cultivars released between 1980 and 2022.Results and discussion. Analysis of variance highlighted a high significant variability between environments (E), cultivars (G), and a significant G × E interaction (P < 0.001). Based on stability analysis, the modern cultivars released during the two last decades (2002–2012 and 2013–2022) showed the highest performances and wider stability than old ones, especially in low-yielding environments. Genetic gain (GG) for GY was 21.4 kg ha−1 yr−1 (0.75% yr–1) over 4 decades of breeding. This progress was declining when advancing in decades and ranged from 11% (from 1980–1990 to 1991–2001) to less than 7% (from 2002–2012 to 2013–2022). The GG in low and intermediate yielding environments were the most important (17.34% and 6.88% yr–1 respectively), while GG was nonsignificant in high-yielding environments (4.62% yr–1). Within the same period, GPC showed a nonsignificant negative trend of –0.007% (–0.002% yr–1), while derivative parameters from GY and GPC indicated high positive genetic progress. More efforts should be deployed to implement a good balance between yield performance and quality in the new released cultivars despite the negative correlation between these two traits (r = –0.36; P < 0.001).Conclusion. Adopting advanced technologies, like genomic selection, adequate agronomic practices, and more efficient selection criteria are essential steps to further increase simultaneously grain yield and quality traits.

Exploiting Indian landraces to develop biofortified grain sorghum with high protein and minerals.

Sorghum (Sorghum bicolor L. Moench) is the staple cereal and is the primary source of protein for millions of people in Asia and sub-Saharan Africa. Sorghum grain value has been increasing in tropical countries including India owing to its gluten-free nature, anti-oxidant properties and low glycemic index. However, the nutrient composition of modern cultivars is declining thus necessitating genetic biofortification of sorghum to combat malnutrition and improve nutritional balance in the human diet. Keeping this in view, efforts were made to utilize valuable alleles, associated with nutrient composition, that might have been left behind in the varietal development in sorghum. The study aimed to determine the genetic improvement for nine nutritional and quality parameters (crude protein, in vitro protein digestibility (IVPD), total iron (Fe), total zinc (Zn), bioavailable Fe (%), bioavailable Zn (%), total phenolics, tannins and antioxidant activity) in the grains of 19 sorghum genotypes (high yield, drought and grain mold tolerant) developed from 11 superior India's landraces. After selection and advancement made from 2017 to 2022 through single seed descent method, the improvement in the nine nutritional and quality parameters was assessed. Significant variation was observed for all the nine parameters among the landraces and the genotypes. Sorghum genotypes PYPS 2 and PYPS 13 recorded the highest crude protein (13.21 and 12.80% respectively) and IVPD (18.68 and 19.56% respectively). Majority of the sorghum genotypes recorded high Fe (14.21-28.41 mg/100 g) and Zn (4.81-8.16 mg/100 g). High phenolics and antioxidant activity were recorded in sorghum genotypes PYPS 18 (85.65 mg/g gallic acid equivalents) and PYPS 19 (89.78%) respectively. Selections through SSD method revealed highest improvement in genotype PYPS 10 for crude protein (32.25%), total phenolics (18.48%) and antioxidant activity (15.43%). High improvements in genotypes PYPS 12 (23.50%), PYPS 3 (26.79%), PYPS 15 (21.18%) were recorded for total Fe, available Fe and high tannins, respectively. The study demonstrated that landraces could be effectively utilized as a potential, low-cost and eco-friendly approach in sorghum genetic biofortification to improved sorghum productivity and nutritional supply in semi-arid tropics.

Revisiting source versus sink limitations of wheat yield during grain filling

AbstractTo further increase wheat (Triticum spp.) yield, we need to understand whether it is source or sink limited. Earlier papers suggested that wheat yield is source limited in modern cultivars, including during the grain‐filling stage. Many recent papers support this interpretation, showing that yield is strongly related to environmental conditions that affect source capacity. In contrast to this, other authors working on source–sink manipulations have concluded that wheat yield is only or predominantly sink limited during grain filling. The objective of this forum paper was to examine this contrasting literature and revisit the assumptions and the interpretation of the results. We found that the arguments for a major sink limitation to wheat yield during grain filling arose from a common approach to quantitatively assess the degree of source–sink limitations, based on relativizing the change in grain weight (in response to source–sink manipulations) to the estimated change in source availability per grain. We show that the estimated changes in source availability with source manipulations are often overestimated in the literature, thus underestimating source limitations. Most importantly, we discuss why relativizing the change in grain weight to the estimated change in source availability biases the interpretation of source versus sink limitations. We conclude that wheat yield is mostly source limited during grain filling, and thus strongly dependent on environmental (including agronomic) conditions. A new model to interpret wheat yield limitations is proposed, describing yield as source limited during the whole crop cycle, including during grain filling.

WATER STRESS IN MODERN UPLAND RICE CULTIVARS: A MULTIVARIATE STUDY BETWEEN PHYSIOLOGICAL TRAITS AND YIELD

Water stress negatively affects upland rice production. The objective of this study was to identify physiological traits that could depict yield responses under water stress conditions. Three modern upland rice cultivars (C) (BRS A501 CL, BRS Esmeralda and BRS Serra Dourada) were subjected to three water availability levels (W): Control (100% of the field capacity throughout the growing cycle) and 70 and 40% of the water applied to the control during flowering. Yield, spikelet sterility, and 1000-grain weight were influenced by the water availability level (p < 0.05), whereas for the cultivar, only 1000-grain weight was significant. The W × C interaction was not significant for the analyzed yield components. Multivariate analysis revealed that well-irrigated plants were positively associated with grain yield and gas exchange traits, whereas the 40% water availability level was highly related to spikelet sterility and the crop water stress index. The best-fitted model for grain yield was obtained using photosynthesis, stomatal conductance, and transpiration (R2 = 0.76). Thus, physiological parameters can be used to explain the variations in upland rice yield under water stress.

Structure and genetic diversity of Canadian Maritimes wild hops.

Studies on the northeastern American native hops (Humulus lupulus ssp. lupuloides) from the Canadian Maritimes are scarce. This study aimed to evaluate the genetic structure and diversity among 25 wild-collected hops from three Canadian Maritime provinces using microsatellite (simple sequence repeat (SSR)) markers. Based on 43 SSR markers, four distinct subgroups were found, with a low molecular variance (19%) between subgroups and a high variance (81%) within subgroups. The Nei's unbiased genetic distance between clusters ranged from 0.01 to 0.08, the genetic distance between clusters 2 and 3 being the farthest and that between clusters 1 and 2 the closest. Cluster 2 captured the highest overall diversity. A total of 18 SSR markers clearly discriminated hop clones by detecting putative subspecies-specific haplotypes, differentiating clones of native-wild H. lupulus ssp. lupuloides from the naturalized old and modern hop cultivars. Seven of the 18 SSR markers also differentiated two clones from the same site from one another. The study is the first, using molecular markers, to identify SSR markers with potential for intellectual property protection in Canadian Maritimes hops. The SSR markers herein used can be prime tools for hop breeders and growers in the region.

Breeding effects on durum wheat traits detected using GWAS and haplotype block analysis.

The recent boosting of genomic data in durum wheat (Triticum turgidum subsp. durum) offers the opportunity to better understand the effects of breeding on the genetic structures that regulate the expression of traits of agronomic interest. Furthermore, the identification of DNA markers useful for marker-assisted selection could also improve the reliability of technical protocols used for variety protection and registration. Within this motivation context, 123 durum wheat accessions, classified into three groups: landraces (LR), ancient (OC) and modern cultivars (MC), were evaluated in two locations, for 34 agronomic traits, including UPOV descriptors, to assess the impact of changes that occurred during modern breeding. The association mapping analysis, performed with 4,241 SNP markers and six multi-locus-GWAS models, revealed 28 reliable Quantitative Trait Nucleotides (QTNs) related to plant morphology and kernel-related traits. Some important genes controlling flowering time and plant height were in linkage disequilibrium (LD) decay with QTNs identified in this study. A strong association for yellow berry was found on chromosome 6A (Q.Yb-6A) in a region containing the nadh-ubiquinone oxidoreductase subunit, a gene involved in starch metabolism. The Q.Kcp-2A harbored the PPO locus, with the associated marker (Ku_c13700_1196) in LD decay with Ppo-A1 and Ppo-A2. Interestingly, the Q.FGSGls-2B.1, identified by RAC875_c34512_685 for flag leaf glaucosity, mapped less than 1 Mb from the Epistatic inhibitors of glaucousness (Iw1), thus representing a good candidate for supporting the morphological DUS traits also with molecular markers. LD haplotype block approach revealed a higher diversity, richness and length of haploblocks in MC than OC and LR (580 in LR, 585 in OC and 612 in MC), suggesting a possible effect exerted by breeding programs on genomic regions associated with the agronomic traits. Our findings pave new ways to support the phenotypic characterization necessary for variety registration by using a panel of cost-effectiveness SNP markers associated also to the UPOV descriptors. Moreover, the panel of associated SNPs might represent a reservoir of favourable alleles to use in durum wheat breeding and genetics.

Genetic erosion within the Fabada dry bean market class revealed by high-throughput genotyping.

The Fabada market class within the dry beans has a well-differentiated seed phenotype with very large white seeds. This work investigated the genetic diversity maintained in the seed collections within this market class and possible genetic erosion over the last 30 years. A panel with 100 accessions was maintained in seed collections for 30 years, 57 accessions collected from farmers in 2021, six cultivars developed in SERIDA, and 16 reference cultivars were gathered and genotyped with 108,585 SNPs using the genotyping-by-sequencing method. Filtering based on genotypic and phenotypic data was carried out in a staggered way to investigate the genetic diversity among populations. The dendrogram generated from genotyping revealed 90 lines forming 16 groups with identical SNP profiles (redundant lines) from 159 lines classified as market-class Fabada according to their passport data. Seed phenotyping indicated that 19 lines were mistakenly classified as Fabada (homonymies), which was confirmed in the dendrogram built without redundant lines. Moreover, this study provides evidence of genetic erosion between the population preserved for 30 years and the currently cultivated population. The conserved population contains 54.6% segregation sites and 41 different SNP profiles, whereas the cultivated population has 19.6% segregation sites and 26 SNP profiles. The loss of genetic variability cannot be attributed to the diffusion of modern cultivars, which increase genetic diversity (six new SNP profiles). The results allow for the more efficient preservation of plant genetic resources in genebanks, minimizing redundant accessions and incorporating new variations based on genotypic and phenotypic data.

Mapping QTL for Yield and Its Component Traits Using Wheat (Triticum aestivum L.) RIL Mapping Population from TAM 113 × Gallagher

Understanding genetic architectures of yield and yield-related traits of wheat (Triticum aestivum L.) grown under dryland or irrigated conditions is pivotal for developing modern high-yielding germplasm and cultivars. The objectives of this study were to detect quantitative trait loci (QTL) linked to yield and yield components using a mapping population derived from ‘TAM 113’/‘Gallagher’, including 191 recombinant inbred lines (RILs). The population was grown in McGregor, College Station, and Bushland, Texas, for three consecutive years from 2019 to 2021. A high-density genetic map covering all 21 chromosomes was constructed using a set of 8,075 single nucleotide polymorphisms (SNPs) obtained using genotyping-by-sequencing (GBS). A total of 147 QTLs for 16 yield-related traits were identified, which included 16 QTLs consistently detected in multiple experiments and 8 QTLs that showed pleiotropic effects. Of them, five pleiotropic QTLs overlapped with the consistent QTL. They increased grain yield (YLD) up to 37.64 g m−2, thousand kernel weight (TKW) up to 1.33 g, harvest (HI) up to 0.97%, kernel length up to 0.08 mm, and kernel width up to 0.04 mm with Gallagher alleles and increased YLD up to 22.21 g m−2, kernels spike−1 up to 1.77, TKW up to 1.14 g, and HI up to 3.72% with TAM 113 alleles. One major and consistent QTL on chromosome 2D at 34.4 Mbp overlapped with the major photoperiod gene Ppd-D1 and was affected by multiple traits, including kernel diameter (DIAM), TKW, kernel hardness index (KHI), heading date (HD), and plant height (PH). Another QTL cluster region on 7D between 52 and 66 Mbp, encompassing one consistent and three pleiotropic QTLs. One of the pleiotropic QTLs at 52 Mbp increased YLD up to 24.16 g m−2, HI up to 1%, and DIAM up to 0.03 mm. This study dissected genetic loci associated with yield and yield-related traits, providing valuable information on wheat improvement using marker-assisted selection (MAS).

Integration of genome-wide association study, linkage analysis, and population transcriptome analysis to reveal the TaFMO1-5B modulating seminal root growth in bread wheat.

Bread wheat, one of the keystone crops for global food security, is challenged by climate change and resource shortage. The root system plays a vital role in water and nutrient absorption, making it essential for meeting the growing global demand. Here, using an association-mapping population composed of 406 accessions, we identified QTrl.Rs-5B modulating seminal root development with a genome-wide association study and validated its genetic effects with two F5 segregation populations. Transcriptome-wide association study prioritized TaFMO1-5B, a gene encoding the flavin-containing monooxygenases, as the causal gene for QTrl.Rs-5B, whose expression levels correlate negatively with the phenotyping variations among our population. The lines silenced for TaFMO1-5B consistently showed significantly larger seminal roots in different genetic backgrounds. Additionally, the agriculture traits measured in multiple environments showed that QTrl.Rs-5B also affects yield component traits and plant architecture-related traits, and its favorable haplotype modulates these traits toward that of modern cultivars, suggesting the application potential of QTrl.Rs-5B for wheat breeding. Consistently, the frequency of the favorable haplotype of QTrl.Rs-5B increased with habitat expansion and breeding improvement of bread wheat. In conclusion, our findings identified and demonstrated the effects of QTrl.Rs-5B on seminal root development and illustrated that it is a valuable genetic locus for wheat root improvement.

Selection and application of four QTLs for grain protein content in modern wheat cultivars

The grain protein content (GPC) is the key parameter for wheat grain nutritional quality. This study conducted a resampling GWAS analysis using 406 wheat accessions across eight environments, and identified four previously reported GPC QTLs. An analysis of 87 landraces and 259 modern cultivars revealed the loss of superior GPC haplotypes, especially in Chinese cultivars. These haplotypes were preferentially adopted in different agroecological zones and had broad effects on wheat yield and agronomic traits. Most GPC QTLs did not significantly reduce yield, suggesting that high GPC can be achieved without a yield penalty. The results of this study provide a reference for future GPC breeding in wheat using the four identified QTLs.

Exploring I, bc-12 and bc-3 Gene Locus in Promising Common Bean Lines

Common beans (Phaseolus vulgaris L.), known as the "poor man's meat", is an internationally important legume crop that appeals to farmers as well as consumers. Many biotic stressors such as bean common mosaic virus (BCMV), bean common mosaic necrosis virus (BCMNV) cause significant yield and quality losses in common bean. The most efficient and cost-effective way to lessen of these factors is to develop resistant cultivars. Local genotypes have been cultivated in many areas for years and have varied distinguishing characteristics as a result of spontaneous mutations. Identifying bean germplasm harboring gene sources is critical for developing resistant cultivars against BCMV and BCMNV. For this purpose, a total of 43 promising common bean lines selected from local genotypes cultivated across various regions of Türkiye were subjected to screening using diverse molecular markers (ROC11, SBD-5 and SW-13) to investigate gene sources associated with BCMV and BCMNV. The findings revealed that 21 lines had both I and bc-12 gene locus. In addition, the bc-12+bc-3 gene loci were discovered to be present in the 8 common bean lines. The combination of I+bc-3 resistance genes, which guarantees immune reaction to BCMV and BCMNV, was found in only one line; YLV-32. These gene sources can be evaluated in marker-assisted breeding to develop modern cultivars resistant to BCMV and BCMNV by breeders.

Whole-genome sequencing of diverse wheat accessions uncovers genetic changes during modern breeding in China and the United States.

Breeding has dramatically changed the plant architecture of wheat (Triticum aestivum), resulting in the development of high-yielding varieties adapted to modern farming systems. However, how wheat breeding shaped the genomic architecture of this crop remains poorly understood. Here, we performed a comprehensive comparative analysis of a whole-genome resequencing panel of 355 common wheat accessions (representing diverse landraces and modern cultivars from China and the United States) at the phenotypic and genomic levels. The genetic diversity of modern wheat cultivars was clearly reduced compared to landraces. Consistent with these genetic changes, most phenotypes of cultivars from China and the United States were significantly altered. Of the 21 agronomic traits investigated, 8 showed convergent changes between the 2 countries. Moreover, of the 207 loci associated with these 21 traits, more than half overlapped with genomic regions that showed evidence of selection. The distribution of selected loci between the Chinese and American cultivars suggests that breeding for increased productivity in these 2 regions was accomplished by pyramiding both shared and region-specific variants. This work provides a framework to understand the genetic architecture of the adaptation of wheat to diverse agricultural production environments, as well as guidelines for optimizing breeding strategies to design better wheat varieties.

Phenotypic evolution in durum wheat (Triticum durum Desf.) based on SNPs, morphological traits, UPOV descriptors and kernel-related traits.

Durum wheat is a worldwide staple crop cultivated mainly in the Mediterranean basin. Progress in durum wheat breeding requires the exploitation of genetic variation among the gene pool enclosed in landraces, old cultivars and modern cultivars. The aim of this study was to provide a more comprehensive view of the genetic architecture evolution among 123 durum wheat accessions (41 landraces, 41 old cultivars and 41 modern cultivars), grown in replicated randomized complete block in two areas, Metaponto (Basilicata) and Foggia (Apulia), using the Illumina iSelect 15K wheat SNP array and 33 plant and kernel traits including the International Union for the Protection of new Varieties of Plants (UPOV) descriptors. Through DAPC and Bayesian population structure five groups were identified according to type of material data and reflecting the genetic basis and breeding strategies involved in their development. Phenotypic and genotypic coefficient of variation were low for kernel width (6.43%) and for grain protein content (1.03%). Highly significant differences between environments, genotypes and GEI (Genotype x Environment Interaction) were detected by mixed ANOVAs for agro-morphological-quality traits. Number of kernels per spike (h2 = 0.02) and grain protein content (h2 = 0.03) were not a heritability character and highly influenced by the environment. Nested ANOVAs revealed highly significant differences between DAPC clusters within environments for all traits except kernel roundness. Ten UPOV traits showed significant diversity for their frequencies in the two environments. By PCAmix multivariate analysis, plant height, heading time, spike length, weight of kernels per spike, thousand kernel weight, and the seed related traits had heavy weight on the differentiation of the groups, while UPOV traits discriminated moderately or to a little extent. The data collected in this study provide useful resources to facilitate management and use of wheat genetic diversity that has been lost due to selection in the last decades.

Defoliation tolerance of soybean cultivars commercially released in different decades

Breeding programs have increased the precocity and yield potential of modern soybean cultivars. Such changes may have altered the crop tolerance to defoliation due to the smaller leaf area of modern cultivars. The objective of this study was to determine the tolerance to defoliation of soybean cultivars commercialized in Brazil in different decades, their photosynthetic efficiency and the relationship between photosynthetic efficiency and tolerance to defoliation in the reproductive phase. The experiment was set in a greenhouse with controlled humidity and temperature, in the municipality of Lages, Santa Catarina State, South of Brazil, during the growing season of 2018/2019. A randomized block design was used, with treatments arranged in a 5×5 factorial scheme. The first factor was composed of five soybean cultivars released in different years: Davis (1968), Paraná (1974), BR-16 (1985), FT Abyara (1991), and Brasmax Elite IPRO (2014). The second factor consisted of five levels of defoliation applied in stage R3: 0, 16.6, 33.3, 50.0, and 66.6%. Leaf area, photosynthetic activity parameters, grain yield and its components were determined. Brasmax Elite IPRO had the lowest grain yield per plant and did not increase yield compared to older cultivars, regardless of defoliation level. There were no significant differences in photosynthetic efficiency or defoliation tolerance between the modern cultivar Brasmax Elite IPRO and the old cultivars Davis, Paraná, BR-16, and FT Abyara.

Yield components and yield quality of old and modern wheat cultivars as affected by cultivar release date, N fertilization and environment in Germany

Wheat (Triticum aestivum L.) is the main staple crop worldwide. Understanding the genotype × management × environment (G × M × E) interaction is critical for breeding, yield, grain quality estimation and to develop sustainable production systems that meet food and feed demand. Many studies have explored grain yield changes and yield stability over time, as well as G × M × E (i.e., the effect of breeding progress), but limited studies have looked at these effects on yield components and grain quality parameters. A field experiment was conducted to understand the G × M × E interactions for yield components of winter wheat cultivars. The study was carried out for three seasons (2015–2018) using a split plot design with four replications, with nitrogen (N) fertilizer levels (0, 120 and 240 kg N ha-1), in the main plot and cultivars in the subplot. Three old cultivars (released before 1960), Heines II, Heines Rot, Heines VII and three modern cultivars (released after 1960), Jubilar, Sperber and Tommi, were selected. Total aboveground biomass (TAGB), grain yield, harvest index (HI), thousand kernel weight (TKW), grains m-2, grain protein and hectoliter weight (HLW) were collected at harvest. The three-way interaction was significant for most variables except for grain protein, but after applying the AIC method, the three-way interaction was just relevant for HI. The 0 N level always resulted in lowest TAGB, grain yield, grains m-2, grain protein and HLW for all cultivars. All cultivars showed a positive response in grain yield when applying 120 kg ha-1 of N but no significant further yield increase was observed with higher N levels. With regards to HI, cultivar differences were more apparent during the wettest year 2016. The HI tends to decrease with increasing N levels and was the highest in modern cultivars with Tommi and Sperber, though in 2017, also Heines VII showed one of the highest HI across treatments. Grain protein content progressively increased with N level, but newer cultivars like Tommi and Sperber, showed some of the lowest protein contents. Yield component contribution to grain yield has changed over time with grain number, grain size and HI, becoming more important for yield realization. Modern cultivars, especially Tommi, performed better than the rest of the cultivars under sufficient N supply. Optimal N-rates among cultivars differ for grain yield and grain protein, posing a challenge to maintain wheat supply to the increasing wheat demand in the future but also to meeting sustainability targets to reduce and optimize resource use.

Comprehensive Evaluation and Transcriptome Analysis Reveal the Salt Tolerance Mechanism in Semi-Wild Cotton (Gossypium purpurascens).

Elevated salinity significantly threatens cotton growth, particularly during the germination and seedling stages. The utilization of primitive species of Gossypium hirsutum, specifically Gossypium purpurascens, has the potential to facilitate the restoration of genetic diversity that has been depleted due to selective breeding in modern cultivars. This investigation evaluated 45 G. purpurascens varieties and a salt-tolerant cotton variety based on 34 morphological, physiological, and biochemical indicators and comprehensive salt tolerance index values. This study effectively identified a total of 19 salt-tolerant and two salt-resistant varieties. Furthermore, transcriptome sequencing of a salt-tolerant genotype (Nayanmian-2; NY2) and a salt-sensitive genotype (Sanshagaopao-2; GP2) revealed 2776, 6680, 4660, and 4174 differentially expressed genes (DEGs) under 0.5, 3, 12, and 24 h of salt stress. Gene ontology enrichment analysis indicated that the DEGs exhibited significant enrichment in biological processes like metabolic (GO:0008152) and cellular (GO:0009987) processes. MAPK signaling, plant-pathogen interaction, starch and sucrose metabolism, plant hormone signaling, photosynthesis, and fatty acid metabolism were identified as key KEGG pathways involved in salinity stress. Among the DEGs, including NAC, MYB, WRKY, ERF, bHLH, and bZIP, transcription factors, receptor-like kinases, and carbohydrate-active enzymes were crucial in salinity tolerance. Weighted gene co-expression network analysis (WGCNA) unveiled associations of salt-tolerant genotypes with flavonoid metabolism, carbon metabolism, and MAPK signaling pathways. Identifying nine hub genes (MYB4, MYB105, MYB36, bZIP19, bZIP43, FRS2 SMARCAL1, BBX21, F-box) across various intervals offered insights into the transcriptional regulation mechanism of salt tolerance in G. purpurascens. This study lays the groundwork for understanding the important pathways and gene networks in response to salt stress, thereby providing a foundation for enhancing salt tolerance in upland cotton.

A promising QTL QSns.sau-MC-3D.1 likely superior to WAPO1 for the number of spikelets per spike of wheat shows no adverse effects on yield-related traits.

A likely new locus QSns.sau-MC-3D.1 associated with SNS showing no negative effect on yield-related traits compared to WAPO1 was identified and validated in various genetic populations under multiple environments. The number of spikelets per spike (SNS) is one of the crucial factors determining wheat yield. Thus, improving our understanding of the genes that regulate SNS could help develop wheat varieties with higher yield. In this study, a recombinant inbred line (RIL) population (MC) containing 198 lines derived from a cross between msf and Chuannong 16 (CN16) was used to construct a genetic linkage map using the GenoBaits Wheat 16K Panel. The genetic map contained 5,991 polymorphic SNP markers spanning 2,813.25cM. A total of twelve QTL for SNS were detected, and two of them, i.e., QSns.sau-MC-3D.1 and QSns.sau-MC-7A, were stably expressed. QSns.sau-MC-3D.1 had high LOD values ranging from 4.99 to 11.06 and explained 9.71-16.75% of the phenotypic variation. Comparison of QSns.sau-MC-3D.1 with previously reported SNS QTL suggested that it is likely a novel one, and two kompetitive allele-specific PCR (KASP) markers were further developed. The positive effect of QSns.sau-MC-3D.1 was also validated in three biparental populations and a diverse panel containing 388 Chinese wheat accessions. Genetic analysis indicated that WHEAT ORTHOLOG OFAPO1 (WAPO1) was a candidate gene for QSns.sau-MC-7A. Pyramiding of QSns.sau-MC-3D.1 and WAP01 had a great additive effect increasing SNS by 7.10%. Correlation analysis suggested that QSns.sau-MC-3D.1 was likely independent of effective tiller number, plant height, spike length, anthesis date, and thousand kernel weight. However, the H2 haplotype of WAPO1 may affect effective tiller number and plant height. These results indicated that utilization of QSns.sau-MC-3D.1 should be given priority for wheat breeding. Geographical distribution analysis showed that the positive allele of QSns.nsau-MC-3D.1 was dominant in most wheat-producing regions of China, and it has been positively selected among modern cultivars released in China since the 1940s. Gene prediction, qRT-PCR analysis, and sequence alignment suggested that TraesCS3D03G0216800 may be the candidate gene of QSns.nsau-MC-3D.1. Taken together, these results enrich our understanding of the genetic basis of wheat SNS and will be useful for fine mapping and cloning of the gene underlying QSns.sau-MC-3D.1.

A Multidisciplinary Study of Wild Grapevines in the River Crati Natural Reserve, South Italy (Calabria): Implications in Conservation Biology and Palaeoecological Reconstructions

Nowadays, wild grapevine populations are quite limited and sporadic mainly due to habitat destruction, land-use change, and the spread of pathogens that have reduced their distribution range. Palaeoecological, archaeobotanical, and genetic studies indicate that modern cultivars of Vitis vinifera are the results of the domestication of the dioecious, and sometimes hermaphrodite, wild species standing in riparian zones and wet environments. Wild grapevine populations have declined as a consequence of various forms of anthropogenic disturbance and were assigned by the IUCN Red List of Threatened Species to the Least Concern category. The River Crati Natural Reserve (Riserva Naturale Foce del Crati), located in southern Italy, hosts a population of Vitis vinifera subsp. sylvestris in a rewilding wet forest close to the Ionian Sea. These protected areas are of high scientific, biogeographic, and conservation interest in terms of Mediterranean biodiversity. Dendroecological and pollen morpho-biometric analyses of the wild grapevine are presented in this study. Palaeoecological perspectives for a landscape management strategy aimed at conserving and restoring the relic grapevine population are discussed.