These findings uncover new QTLs for PM resistance in strawberry, including on fruit, and provide validated strategies for breeding disease-resistant cultivars.
Abstract
Powdery mildew (PM) is a major fungal disease of cultivated strawberry, reducing yield through severe damage to foliage and fruit. Increasing restrictions in pesticide use have intensified the need for PM resistant cultivars. Here, we investigated the genetic architecture of PM resistance in strawberry using a large, untapped germplasm composed of two panels: a diversity panel of 223 genotypes (DivPanel) and a connected population (CoPop) panel comprising six selfed families and 12 biparental families derived from six cultivars. Disease symptoms were assessed on leaves and fruits over multiple years, indicating moderate to high heritability in the two organs. Genome-wide association studies identified 21 leaf QTLs, most of which are new; and 10 fruit QTLs. Among these, only one leaf QTL was co-localized with a fruit QTL, revealing that the genetic architecture of PM resistance is different in leaves and fruits. Genomic prediction models were evaluated through cross-validation and external validation, with combined-over-year analyses showing the highest predictive abilities (PAs) for both panels and organs (0.45–0.73). For a given year, optimizing the training population and adding co-factors improved the PAs. External validation also showed intermediate PA values (0.48–0.63), depending on the training population size and optimization. Simulation of resistance levels in 24 753 simulated progenies derived from all possible crosses between the 223 genotypes of the DivPanel demonstrated the strong potential of genomic prediction to guide optimal cross selection. Together, these findings uncover new QTLs for PM resistance in strawberry, including on fruit, and provide validated strategies for breeding disease-resistant cultivars.
Wheat (Triticum aestivum L.) is an economically important cereal crop. Its genetic diversity is a prerequisite for successful breeding for resistance to leaf and stem rust, as well as for other important traits. Therefore, the main objective of the study was to determine the level of genetic diversity of a file of 185 wheat accessions chosen to represent a wide range of resistance levels to leaf and stem rusts. They were evaluated at two locations in three years (2023–2025) for leaf and stem rust resistance by means of visual evaluation and fungus content using real-time PCR. BLUP values were then computed from these multi-environmental data. In addition, data on other traits such as heading time, plant height, and grain quality were collected. In the PCA, grain quality variables represented the first factor, explaining 41% of the total variability. Rust resistance was mainly associated with the second and the third factor. Population analysis revealed primary two (K = 2) and secondary six (K = 6) clusters, computed by using 13,274 DArT markers. The correlation between genotype and phenotype data was high (R = 0.89) when all traits were analyzed, and lower (R = 0.58) when only leaf and stem rust resistance variables were considered. Genetic diversity was also studied through an association analysis between markers and phenotypic traits using GLMs and MLMs. As a result, 300 statistically significant marker-trait associations (MTAs) were identified (p ≤ 3.77 × 10−6). Of these MTAs, 180 were associated with rust resistance variables and 120 with other traits. A BLAST search of rust resistance MTAs identified 128 putative genes; 47 of them can be taken for candidate genes related to fungal resistance. The results show that association analysis can help to explain the genetic diversity of selected wheat accessions, and that leaf and stem rust resistance are complex traits involving many non-specific resistance genes.
Leona Leišová-Svobodová, Stanislav Ježek, O. Veškrna et al.· Agronomy· 0 citations
Tomato (Solanum lycopersicum L.) is an important vegetable crop valued for its nutritional quality, wide adaptability and economic significance. The present study was conducted to evaluate genetic variability, character association and genetic diversity among tomato accessions for yield and its contributing traits. The experiment was carried out during the spring-summer season of 2020 and 2021 at the experimental field of horticulture, School of Agriculture, Lovely Professional University. A total of 26 tomato accessions, comprising 6 repatriated genotypes and 20 hybrids developed through a full diallel mating design, were evaluated in a randomised complete block design (RCBD) with 3 replications and 15 quantitative and quality-related characters. Significant variation was found among the different germplasms for all characters. Yield and yield contributing characters showed high heritability along with genetic gain, indicating major role of these characters in expression of these characters. Yield per plant exhibited a strong and positive relationship with number of fruits per plant, fruit width, fruit length and mean fruit weight. Path coefficient analysis indicated that the number of fruits per plant and reducing sugar content exerted the highest positive direct influence on yield. Principal component analysis explained 81.70 % of the total variation through five components. Cluster analysis grouped accessions into two major clusters irrespective of geographic origin, indicating wide genetic diversity. Accessions T10 and F1022 were identified as the most divergent and may serve as promising parents for yield improvement in tomato breeding programs.
S. Vinit, K. Khushboo, T. Nikhil et al.· Plant Science Today· 0 citations
The cultivated strawberry (
Fragaria
×
ananassa
Duch.) is an economically important fruit crop. Improvement of fruit quality is a major breeding objective. Although numerous quantitative trait loci (QTLs) have been identified for fruit‐related traits, less information is available on quality attributes such as fruit mass, total soluble solids (TSS) and susceptibility to water soaking (WS). The objective of our study is to identify and validate genetic regions associated with fruit mass, TSS and WS susceptibility using a model population derived from an interspecific cross between
F
. ×
ananassa
and
Fragaria chiloensis
. Phenotyping was conducted in three seasons, and QTL analysis was performed using an already existing linkage map consisting of 2990 SNP markers. The introgression of the wild‐type
F. chiloensis
resulted in a decrease in fruit mass and an increase in fruit TSS. Annual broad‐sense heritabilities
H
2
indicated that the expression of all three traits is affected by genetic but also by environmental factors (
H
2
ranging from 0.27 to 0.68). Multiple QTLs for each trait were identified, with significant QTLs explaining up to 27% of the phenotypic variation. For TSS content, QTLs on linkage group 1C, 3A and 4A; and for WS susceptibility, QTLs on linkage group 1B, 1C, 4A and 6D were stable in at least two seasons. None of the QTLs was stable for fruit mass. This study confirmed the polygenic and complex nature of fruit mass, TSS and WS susceptibility. Some regions involved in these traits could be validated in our study, thus providing useful insights for breeding of cultivars with improved fruit mass, TSS content and tolerance against WS.
Diana Seidler, Grecia Hurtado, Moritz Knoche et al.· Plant Breeding· 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
Optimizing leaf morphology is essential for improving maize plant architecture, plant density tolerance, and yield. Leaf length is a key agronomic trait controlled by complex genetic mechanisms. In this study, upper leaf length (ULL), ear leaf length (ELL) and lower leaf length (DLL) were evaluated across two environments using a multiparent RIL population derived from crosses between the temperate inbred line Ye107 and three tropical inbred lines. Combined with high-density GBS markers, genome-wide association study (GWAS) and QTL mapping were integrated to dissect the genetic basis of leaf length.
Leaf length traits exhibited high heritability (54.85%–76.85%). A total of 133 significant SNPs were identified by GWAS, and 13 candidate regions were detected by QTL localization, among which
ql1-17
explained 12.10% of the phenotypic variation. Joint analysis revealed multiple colocalized regions on chromosomes 1, 6 and 8, resulting in the identification of three key candidate genes
ZmHUA2 (Zm00001d029223)
,
ZmCAMTA5 (Zm00001d025235)
, and
ZmPAT16 (Zm00001d038367)
. Haplotype and qRT-PCR analyses showed that favorable haplotypes from tropical parents significantly increased leaf length, and these genes exhibited high expression specificity in the leaf elongation region.
This study elucidates the complex genetic architecture of leaf length in temperate × tropical hybrid populations. Through integrated analyses, we identified key genomic loci and prioritized three candidate genes, particularly
ZmHUA2 (Zm00001d029223)
and
ZmCAMTA5 (Zm00001d025235)
. These findings provide valuable genomic resources and favorable alleles for marker-assisted selection, establishing a robust theoretical and practical foundation for maize ideotype breeding aimed at optimizing leaf morphology to enhance yield potential under high-density planting conditions.
Haoran Lyu, F. Jiang, Yuxiang Luo et al.· BMC Plant Biology· 0 citations
The study focused on evaluating 48 different tomato genotypes for 13 morphological traits to estimate the genetic variability, heritability and genetic advance at the Horticulture Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology in Meerut, following randomized complete block design with three replications during two consecutive Rabi seasons (October 2022 and April 2024). The results of analysis of variance revealed that for all quantitative features included for both the season, analysis of variance indicated highly significant variations among genotypes. The phenotypic and genotypic coefficient of variation ranged from 4.92% to 16.42% and 4.23%to12.93% respectively. Higher PCV compared to GCV observed for all traits revealed that the influence of environment on traits. High heritability estimates obtained for day to first fruit set, days to first fruit maturity, plant height, days to first fruit harvesting, days taken germination, number of fruits per plant, fruit yield(t/ha), fruit length, fruit yield (kg/plant), fruit yield (kg/plot), High Genetic Advance for number of primary branch, plant height, fruit length, days to first fruit set. High heritability coupled with High Genetic Advance Observed for day to first fruit set, plant height, days to first fruit set, fruit length. As yield is the most important dependent trait, day to first fruit set, plant height, days to first fruit set, fruit length can be selected as selection parameters for further crop improvement programs.
