Crop Science最新文献

The re-emergence of wheat stem rust disease, caused by Puccinia graminis Pers. f. sp. tritici (Eriks and E. Henn.) (Pgt), has recently been reported in Europe and North Africa. The prevalence of virulent Pgt genetic groups in Mediterranean basin countries, combined with the limited number of characterized resistance sources in durum wheat (Triticum turgidum L., ssp. durum (Desf.) Husn.) germplasm, poses a serious threat to durum wheat production. In this study, we evaluated a collection of Mediterranean wheat accessions, mainly durum wheat, for seedling stage resistance to two Ug99 races (TTKTT and TTKSK) and the recently emerged and prevalent races TTRTF (aka Sicily race) and TKKTF. Although 24% of the genotypes exhibited resistant responses, phenotyping screening showed significant variation in seedling responses to the different races. Specifically, 27% and 30% of the genotypes were resistant to TTRTF and TTKSK, whereas only 17.5% and 18% exhibited resistance to TKKTF and TTKTT, respectively. Only 9.4% of genotypes (n = 13) exhibited resistance or intermediate responses to all four tested races. Wheat accessions from Portugal, France, and Spain showed the highest resistance frequencies, ranging from 30% to 50%. Molecular analysis revealed the presence of the resistance gene Sr13 in 13 genotypes, eight of which originated from Tunisia (one landrace and seven varieties). The study demonstrates the importance of Mediterranean durum wheat accessions as sources of novel and diverse genetic resistance to the predominant races in the Mediterranean region, especially to the TTRTF, TKKTF, and Ug99 lineage races.

Genetic gain is an annualized measure of trait improvement used to estimate plant breeding progress, wherein the performances of old versus new variety releases are compared over time. Herein, we present data from the United States Department of Agriculture-coordinated hard winter wheat (Triticum aestivum L.) Southern regional performance nursery (SRPN) collected from 1959 to 2024 for grain yield, grain volume weight, days-to-heading, and plant height and use it to estimate absolute and relative rates of genetic gain (loss) of the control cultivar Kharkof for winter wheats adapted to the Southern Great Plains of North America. Regression analyses revealed significant relative grain yield increases of 0.90% Kharkof year⁻¹ and 24.4 kg ha⁻¹ year⁻¹ for the SRPN over the 66-year period. Notwithstanding, nonlinear statistical modeling of SRPN relative and absolute grain yield datasets provided the most parsimonious fit of the data, revealing highly significant linear breakpoints (i.e., plateaus) beginning in 1998 for relative %Kharkof yield, with quadratic models best explaining absolute (kg ha⁻¹ year⁻¹) yield data for the region, suggesting a more gradual leveling off of grain yield over time instead of an abrupt breakpoint. Trends for both relative and absolute grain yield of 0.57% Kharkof year⁻¹ and 15.4 kg ha⁻¹ year⁻¹, respectively, since 1984 further demonstrate reduced annualized gains in comparison to the 66-year trendlines. These broad-sense, proxy estimates of genetic gain reported herein reconfirm that wheat breeding progress remains difficult in many marginal production environments constituting the US Southern Plains, but the parabolic best-fit curve for absolute kg ha⁻¹ year⁻¹ grain yield of 5MP and all SRPN entries indicates that yield gains are still moderately increasing.

Increasing selection accuracy for parental lines in the early stages of a breeding program can significantly shorten the breeding cycle and accelerate genetic gain. Public breeding programs have limited resources, which in many cases implies not having enough funds for genomic selection. In this study, we propose a strategy that allows leveraging a data source that is often overlooked: the breeding program's historical data. We evaluated the impact of incorporating historical data through multi-environment analysis for selection at early stages of evaluation in a public breeding program. Two distinct breeding goals were assessed: line advancement and parent selection. For the first objective we used available phenotypic data, and for the second objective we leveraged existing pedigree records in addition to the phenotypic data. The evaluation strategy employed replicated the breeding program's structure, accounting for the timing of data availability. We investigated five prediction strategies, starting from single trial analysis, incorporating one or 5 years of historical data, and including or not a genotype by environment interaction term. To compare the prediction strategies, we considered grain yield phenotypic variance partition and predictive ability. Joint analysis of multiple trials and environments led to more accurate estimations of variance components and higher predictive ability for early selection of parents and line advancement. Additionally, we found that modeling genotype by environment interaction did not consistently enhance predictive ability. This study highlights the benefits of joint analyses of multi-environment trials for early selection of parents and lines in breeding programs.

In snap bean (Phaseolus vulgaris L.) production, herbicides are essential for weed control, requiring crop tolerance to avoid injury. The study aimed to link genomic loci to agronomic traits, explore the extent of herbicide cross-tolerance, and identify loci influencing seed vigor and herbicide tolerance traits. A panel was evaluated for seven agronomic traits and two measures of tolerance to eight herbicides. Genome-wide association studies (GWASs) identified marker-trait associations (MTA) and candidate genes. Heritability confirmed genetic control over agronomic traits. Seed weight and traits measuring seed and at-flowering vigor showed positive correlations. Multilocus GWAS identified 179 MTA for seven agronomic traits, with 28 regions linked to multiple traits. Candidate genes included those involved in cell wall synthesis, DNA repair and methylation, radical oxygen species scavenging, and signal transduction. Identified candidate genes related to flowering provide insights into flowering control beyond TFL1. Positive correlation between herbicide cross-tolerance and seed vigor traits suggests shared mechanisms. Multi-trait GWAS identified genomic regions linked to herbicide cross-tolerance and seed vigor traits. Across all trait groupings, 69 multi-trait MTAs were identified. Chromosomes 1, 2, 4, and 8 regions were associated with seed vigor measures under herbicide and control conditions in multiple analyses. Favorable alleles for stress tolerance operate independently of growth habit and ancestry and were present in higher frequencies in lines with Middle American ancestry. This research highlights genetic links between herbicide tolerance and plant fitness, identifying loci associated with agronomic traits, and provides resources for breeding of snap beans with enhanced resilience and agronomic performance.

Tall fescue (TF) [Schedonorus arundinaceus (Schreb.) Dumort.] continues to increase in popularity in the northern and transitional climatic zone of the United States because of its superior heat and drought tolerance compared to Kentucky bluegrass (KB) (Poa pratensis L.). However, most turf-type TF cultivars have a bunch-type growth habit that hinders their potential to produce high sod strength for sod producers. New TF cultivars have been marketed as “spreading” or “rhizomatous” tall fescue (RTF); however, research is needed on establishment, rhizome, and sod strength characteristics. Repeated field experiments at Kansas State University were conducted to measure establishment speed and sod strength and handling at three harvests: 9, 10, and 12 months after planting. Additionally, controlled-environment experiments were conducted to measure germination speed and rhizome characteristics. While TF cultivars had faster establishment speed and germination speed compared to KB, both bunch-type TF and RTF cultivars did not produce similar high-quality sod strength when compared to a 100% KB sod, which produced the highest sod strength across all three sod harvests. Controlled environment experiments revealed that KB cultivars produced ≥ 96% greater rhizome lengths compared to RTF after 4.3 months. Rhizome lengths averaged ≤3.1 mm in RTF compared to >80 mm in KB. However, there was no relationship present between rhizome characteristics and earliest sod strength data. Rhizome production and sod strength is considerably less in both bunch-type TF and RTF compared to KB, and results will assist sod producers and turfgrass breeders in future selections to meet increasing challenges and market demands.

Breeding for heat tolerance in soybean [Glycine max (L.) Merr.] is constrained by limited genetic diversity for heat tolerance, lack of efficient selection criteria, and incomplete knowledge of heat tolerance mechanisms. The objectives of this study were to characterize the heat tolerance of a soybean recombinant inbred line (RIL) population based on physiological traits defining leaf function, pollen viability, and yield, and identify genotypes and traits that can be included in breeding programs for heat tolerance selection. Field trials were conducted in South Carolina in 2022 and 2023 to test 192 RILs (derived from DS 25-1 [heat-tolerant] × DT97-4290 [heat-susceptible]), parental lines, and 12 check genotypes. Plants were initially grown at ambient temperatures, and the heat stress treatment (38°C–42°C for at least 4 h during the daytime) was established using heat tents for 14 days during the R2–R4 growth stages. RILs 22, 26, 38, 54, 78, and 115 were identified as the most heat-tolerant, and the RILs 174, 182, and 192 as the most heat-sensitive based on leaf physiological traits (chlorophyll index, chlorophyll fluorescence, lipid peroxidation, and photosynthesis), pollen viability, aboveground biomass, seed number, seed yield, and 100-seed weight. Seed yield was positively correlated with chlorophyll index, photosynthesis, aboveground biomass, and seed number under heat stress. Aboveground biomass had the highest heritability (H² = 0.48), reinforcing its significance as a key selection criterion for heat tolerance in soybean. New heat-tolerant germplasms identified in this research and the three physiological traits for improving selection efficiency provide valuable resources for soybean varietal development programs.

Common bean (Phaseolus vulgaris L.) is considered a staple of the Brazilian diet and one of the most important grains in the diets of populations in several countries across Latin America, Africa, and Asia, as it is an excellent source of proteins, vitamins, carbohydrates, minerals, and fiber. This study aimed to evaluate the adaptability and stability parameters of grain yield in black common bean using methods based on analysis of variance, as well as simple and two-segment linear regression. The trials were conducted using a randomized block design with three replicates, in three municipalities, in 2016 and 2017, totaling six environments. Each experimental unit consisted of four 4-m-long rows, spaced 0.5 m apart, totaling a population of 240,000 plants ha⁻¹. The usable area comprised the two central rows, excluding 0.5 m from each end, totaling 3 m². Six genotypes, including four elite lines, had yields above the overall mean and were considered the best adapted. The methodologies proposed by Eberhart and Russel, Wricke, Lin and Binns, and Cruz et al. showed agreement in identifying the Centro Nacional de Pesquisa em Feijão Preto (CNFP) 15684 inbred line as having broad phenotypic stability. The Eberhart and Russel method was effective in identifying genotypes with broad adaptability and high phenotypic stability, indicating the CNFP 15685 genotype for cultivation in the north and northwest regions of Rio de Janeiro. No ideal genotype—that is, one that is productive, adapted to unfavorable environments, responsive to environmental improvement, and highly stable—was identified by the method of Cruz et al.

Fumonisins are mycotoxins produced by the fungal pathogen, Fusarium verticillioides, and they are widespread in corn (Zea mays L.), especially in the Southeastern United States. While there are several post-harvest mitigation strategies to reduce fumonisin, there are limited studies testing pre-harvest strategies. Therefore, field studies were conducted at two locations in Mississippi to examine the impact of agronomic practices in mitigating fumonisin accumulation in corn. The experiments were set up in a split-plot design, with nitrogen (N) (0, 112, 224, and 336 kg N ha⁻¹) as main plot factor and combination of plant populations (PPs) (75,000, 87,500, 100,000, and 112,500 plants ha⁻¹) and corn hybrids (H) with and without Bacillus thuringiensis (Bt) traits (DKC70-27 and 70-25, respectively, where DKC is Dekalb corn) as subplot factors. Ten ears per plot were inoculated with F. verticillioides for subsequent post-harvest fumonisin quantification. In 2024, fumonisin accumulation was significantly influenced by H × PP interaction (p < 0.05) and ear rot severity was influenced by N × PP interaction (p < 0.05) in Starkville, whereas in 2023, only the main treatments affected fumonisin accumulation in Starkville and Brooksville. Overall, the Bt hybrid showed significantly lower ear rot severity and fumonisin accumulation. Moreover, fumonisin accumulation decreased with an N rate of 112 kg N ha⁻¹ in Starkville, without any noticeable differences at higher N rates. In summary, this study identified that the best preharvest strategy to mitigate fumonisin includes selecting hybrid with Bt traits for reducing insect injury to the ear, maintaining a planting density between 75,000 and 87,500 plants ha⁻¹, and applying at least 112 kg N ha⁻¹ for minimizing nitrogen deficiency.

Cercospora leaf spot (CLS) disease, caused by the fungus Cercospora beticola Sacc., and sugarbeet root maggot (SBRM, Tetanops myopaeformis [von Röder] [Diptera: Ulidiidae]) cause significant sugarbeet (Beta vulgaris L. [Caryophyllales: Amaranthaceae]) yield loss in the United States. Identification and utilization of resistance sources from wild sea beet (B. vulgaris ssp. maritima (L.) Arcang), the progenitor of all cultivated beet biotypes (sugarbeet, fodder beet, and table beet), will not only enhance sugarbeet resistance to pest and diseases but also broaden its genetic base for sustainable improvement. This research evaluated resistance/tolerance to CLS and SBRM feeding injury in 300 core Beta maritima accessions under multiple environments. The core accessions, obtained from publicly available collections in the United States, were selected based on a comprehensive phylogenetic analysis. A set of 42 accessions consistently exhibited resistance to CLS, of which 18 accessions belonged to sub-populations that are genetically distinct from cultivated sugarbeet. Another 32 accessions showed minor SBRM feeding injury to roots under varied environments and were considered tolerant. Nineteen of those accessions are genetically diverse from cultivated sugarbeet. A total of 11 accessions exhibited resistance/tolerance to both CLS and SBRM. The accessions identified as expressing host plant resistance to CLS and SBRM will be valuable sources with which to diversify commercial sugarbeet germplasm, and those showing distinct genetic distances from cultivated sugarbeet should have high potential to introduce novel genetic variations to broaden the sugarbeet genetic base.

Kodjovi, G. C., Coulon, M., Couturier, L., Morin, A., Goma-Louamba, I., Artault, C., Tcherkez, G., Vriet, C., La Camera, S., Pourtau, N., Moumen, B., & Doidy, J. (2025). A transcriptomic atlas facilitating systems biology approaches in pea. Crop Science, 65, e70194. https://doi.org/10.1002/csc2.70194

The Supplemental Material file that contained Supplemental Tables S1–S10 was inadvertently left out of the published paper. This has now been corrected. In addition, a citation for Table S10 has been placed in “Section 3.4.1 Validation of reference genes by RT-qPCR” in the sentence “The reference genes exhibited a mean Ct value ranging from 22.4 to 27.5 across all experiments, with Psat0s3790g0040 showing the highest expression and Psat5g227600 the lowest expression levels, respectively (Figure 4A; Table S10).”

The Supplemental Information section has also been updated with Table S10's caption: “Table S10: Raw Ct data of the top 10 reference genes and common housekeeping genes (TFIIA, PP2A, and β-tubulin) from qPCR performed on the three experiments (see details in Material & Methods section).”

We apologize for this error.