2026· Ciência e Agrotecnologia· 0 citations· 54 references
Abstract
ABSTRACT The tomato (Solanum lycopersicum L.) is one of the most important vegetables from an economic, social, and nutritional point of view, being widely consumed throughout the world, both fresh and processed. Due to its importance, this crop is a constant focus of genetic improvement programs that seek to develop superior genotypes, such as higher quality, yield, and disease resistance. Thus, the aim of this study was to select experimental indeterminate Italian tomato hybrids with high yield, superior fruit quality, and resistance to TSWV (tomato spotted wilt virus) via molecular markers. The trial was conducted in the municipality of Ijaci, southern Minas Gerais, Brazil. A randomized block design was used, with 16 hybrids (12 experimental and 4 commercial controls), four replications, and five plants per plot. Evaluations were carried out for yield, fruit quality, and resistance to TSWV under natural infection and through molecular markers to identify the Sw5 gene. Six experimental hybrids stood out in terms of high yield, with hybrid TO-014 being superior to the others, presenting better size and higher commercial classification. Most genotypes showed few defects, revealing good qualitative characteristics, with the exception of three hybrids (TO-004, TO-042, and TO-134), which demonstrated greater susceptibility to TSWV. Seven experimental hybrids were considered resistant to TSWV because they carry the Sw-5 gene and did not show symptoms of infection in the field. Six of these hybrids also stood out in terms of yield and fruit quality, demonstrating that resistance to the virus has a direct impact on productive characteristics.
Tomato spotted wilt virus (TSWV) and late leaf spot (LLS) are among the major constraints to peanut production. Cultivated peanut has narrow genetic bases and lacks strong sources of resistance. Wild species, on the other hand, harbor diverse and strong resistances to multiple pathogens. In this study, we evaluated advanced breeding lines carrying introgressions from multiple wild Arachis species (A. stenosperma, A. batizocoi, A. valida, and A. cardenasii) across three contrasting field environments and experimental designs in Georgia, USA using complementary incidence- and severity-based phenotyping. Genotype effects were highly significant for both diseases. Several wild-derived lines -particularly those from A. stenosperma ancestry- showed strong and stable TSWV resistance across environments. Interestingly, some lines lacking detectable wild segments also showed high resistance to TSWV, suggesting cryptic or undetected introgressions. LLS resistance was primarily associated with the characteristic A. cardenasii segments on A02 and A03, and lines stacking these introgressions consistently outperformed both cultivated parents and Georgia-06G, the most popular cultivar in the USA. Correlations between TSWV and LLS responses were weak, confirming genetic independence and emphasizing the need to screen both traits. A small subset of lines combined resistance to both diseases, and many also retained resistance loci to root-knot nematode (RKN), expanding their value as multi-trait donors. These findings demonstrate the power of wild introgression breeding for enhancing disease resistance and provide a foundation for deploying stacked alleles through marker-assisted and multi-environment selection.
Namrata Maharjan, A. Culbreath, M. Gonzales et al.· Plant Disease· 0 citations
Genetic variability generated through segregation provides an effective opportunity to identify superior recombinants for tomato improvement. The present investigation was conducted using the F₂ population derived from the cross IIHR-2761 × IIHR-2725. The experiment was conducted during Rabi 2025 at the Main Agricultural Research Station, University of Agricultural Sciences, Dharwad. A total of 175 F₂ plants were evaluated for ten quantitative traits associated with growth and yield. Moderate to high variability was observed for most of the traits studied. High PCV was recorded for number of fruits per cluster (22.99%), number of fruits per plant (25.17%) and fruit yield per plant (27.09%), whereas moderate GCV was observed for number of branches per plant (12.69%), number of clusters per plant (12.62%) and fruit yield per plant (19.91%). High broad-sense heritability was observed for plant height (98.39%), days to maturity (93.04%), number of branches per plant (79.49%) and number of clusters per plant (68.45%), while high genetic advance as per cent of the mean was recorded for fruit yield per plant (30.15%), number of branches per plant (23.31%) and number of clusters per plant (21.50%), indicating favourable prospects for selection. Frequency-distribution analysis revealed both positive and negative skewness among the studied traits, suggesting differential gene action governing their inheritance, whereas most traits exhibited platykurtic distributions, indicating polygenic control. Several superior transgressive segregants beyond the mean ±1 SD and mean ±2 SD thresholds were identified for yield and its associated traits, particularly number of fruits per cluster, number of fruits per plant and fruit yield per plant. The identified segregants provide valuable breeding material for developing high-yielding tomato cultivars through selection in advanced generations.
I. Jyoti, S. A. Desai, K. Narendra et al.· Journal of Advances in Biolo...· 0 citations
In Mexico, the predominant commercial Solanum lycopersicum L. varieties are red. Nevertheless, materials with alternative pigmentations can serve as a source of genetic variation for the expression of diverse fruit colors while providing nutraceutical properties of interest. The aim of this study was to determine the agronomic performance of hybrids derived from nine contrasting parents with different fruit shapes, colors, and indeterminate growth habits, as well as their direct crosses, for agronomic, color, and fruit quality traits in order to select outstanding genotypes. Twenty crosses were obtained by combining four elite red female parents with five male color donors. The experiment was established under a randomized complete block design with four replications and 10 plants per experimental unit. Yield components, fruit quality, and color characteristics were evaluated. The agronomic performance of the crosses and parents was estimated, along with mean heterosis, high-parent heterosis, and type of gene action. Significant differences among crosses were detected for all evaluated variables, except for the color component b*. Crosses involving the pink parent showed higher values for yield components, whereas crosses involving orange parents exhibited better fruit quality. Phenotypic values among parents were significant for total fruit weight (TFW), total number of fruits (TNF), days to flowering (DF), days to maturity (DM), and the color variables L*, a*, and b*. Mean heterosis reached values of up to 94.5 %, indicating average effects of partial dominance and dominance toward the male parent.
Mitzy Tiare Arenas-Santos, S. Cruz-Izquierdo, R. Lobato‐Ortiz et al.· Agrociencia· 0 citations
Potato viral infections are among the main factors contributing to reduced quality of planting material and decreased tuber productivity. Currently, no reliable chemical control methods are available for plant viral diseases. Therefore, the development of potato cultivars carrying virus resistance genes remains one of the most effective and comprehensive approaches to this problem. In this study, 29 Russian and foreign potato cultivars, as well as 31 Far Eastern potato hybrids were evaluated. Resistance genes were identified using PCR analysis. The following cultivars carrying target resistance genes were used as positive controls for method calibration: Meteor (Rysto, Rx1, Sen1, Gpa2, H1), Vektor (Rx1, Gpa2), Yubilyar (Gpa2), and Zhukovsky ranniy (Gpa2, Rx1). Method calibration enabled determination of optimal magnesium chloride concentrations: 2.0 mM for Gpa2 and 2.5 mM for Rx1. Genotyping of 29 potato cultivars identified several highly resistant accessions, including Yubilyar, Zhukovsky ranniy, Bellarosa, Sante, Smak, Red Scarlett, and Laperla. These cultivars combined resistance to Potato virus X (Rx1) with complex resistance to two nematode species (Gpa2, H1). In the studied population, high frequencies of the Gpa2 (82.8%) gene and the H1 (65.5–69.0%) gene group were observed. Statistical analysis provided strong evidence for tight genetic linkage between the Rx1 and the Gpa2 loci on chromosome 12. The association was highly significant (p < 0.001). Analysis of 31 potato hybrids revealed 14 multi-marker genotypes with high breeding potential. A stable combination of five target resistance markers was consistently detected in their genomes. A dominant hybrid family derived from the Yantar × Smak cross was identified, represented by five related lines. For the first time, a precise heritability coefficient was calculated for the STS marker of the Rx1 gene in a Far Eastern hybrid population. The estimate reached h2 = 0.835 at p = 0.01. This value significantly exceeded the critical threshold for breeding reliability (h2 > 0.7), indicating largely additive genetic control of the trait. These results support targeted selection of parental combinations for breeding programs aimed at improving virus and nematode resistance in potato.
Irina V. Kim, O. Sobko, P. Fisenko et al.· Plants· 0 citations
Bacterial wilt caused by Ralstonia solanacearum is one of the most destructive soil-borne diseases limiting tomato production in tropical regions. The identification of tolerant genotypes remains the most sustainable strategy for managing the disease, particularly in endemic zones of South-Western Nigeria. This study evaluated eleven tomato (Solanum lycopersicum L.) genotypes comprising seven NIHORT accessions, one commercial hybrid (F1 Cobra 26), and three local varieties for tolerance to bacterial wilt under controlled screenhouse conditions. The experiment was arranged in a 2 × 11 factorial and laid out in a Randomized Complete Block Design (RCBD) with three replicates. Plants were artificially inoculated using a standardized bacterial suspension adjusted to 2 × 10⁹ CFU ml⁻¹. Disease incidence was calculated as a percentage of symptomatic plants per genotype. Significant differences (p < 0.05) were observed among genotypes for disease incidence and wilting severity. Disease incidence ranged from 16.0% in F1 Cobra 26 to 53.4% in NHTO 0199 under inoculated conditions, with susceptible genotypes exhibiting severe wilting symptoms. On the other hand, selected NIHORT accessions demonstrated comparatively lower disease severity and delayed symptom expression, indicating partial tolerance to R. solanacearum. The findings reveal substantial genetic variability in response to bacterial wilt and highlight the potential of specific improved accessions as candidate materials for breeding and cultivation in wilt-endemic regions. Adoption of tolerant genotypes is strongly recommended as a core component of integrated bacterial wilt management strategies.
A. O. Oloniluyi, V. Esan, A. Adekiya· Pakistan Journal of Phytopat...· 0 citations