Bruchid beetles are an important storage pest of grain legumes. Callosobruchus sp. infect mungbean (Vigna radiata) at low levels in the field, multiply during grain storage and can destroy seed stocks in a few months. Resistance against bruchid beetles has been found in wild mungbean V. radiata var. sublobata TC1966 and in cultivated mungbean line V2802. Bruchid resistance data were obtained from recombinant inbred line populations TC1966 (V. radiata var. sublobata) × NM92 (F12) and V2802 (V. radiata) × NM94 (F7). More than 6,000 single nucleotide polymorphic markers were generated through genotyping by sequencing (GBS) for each of these populations and were used to map bruchid resistance genes. One highly significant quantitative trait locus (QTL) associated with bruchid resistance was mapped to chromosome 5 on genetic maps of both populations, suggesting that TC1966 and V2802 contain the same resistance locus. Co-segregation of all markers associated with resistance indicated the presence of only one major resistance QTL on chromosome 5, while QTL analysis based on physical map positions of the markers suggested the presence of multiple QTLs on different chromosomes. The diagnostic capacity of the identified molecular markers located in the QTL to correctly predict resistance was up to 100 %. Molecular markers tightly linked to bruchid resistance loci of two different mungbean resistance sources were developed and validated. These markers are highly useful for developing resistant lines.

Mungbean (Vigna radiata (L.) R. Wilzeck var. radiata) is a protein-rich short-duration legume that fits well as a rotation crop into major cereal production systems of East and South-East Asia. Salinity stress in arid areas affects mungbean, being more of a glycophyte than cereals. A significant portion of the global arable land is either salt or sodium affected. Thus, studies to understand and improve salt-stress tolerance are imminent. Here, we conducted a genome-wide association study (GWAS) to mine genomic loci underlying salt-stress tolerance during seed germination of mungbean. The World Vegetable Center (WorldVeg) mungbean minicore collection representing the diversity of mungbean germplasm was utilized as the study panel and variation for salt stress tolerance was found in this germplasm collection. The germplasm panel was classed into two agro-climatic groups and showed significant differences in their germination abilities under salt stress. A total of 5288 SNP markers obtained through genotyping-by-sequencing (GBS) were used to mine alleles associated with salt stress tolerance. Associated SNPs were identified on chromosomes 7 and 9. The associated region at chromosome 7 (position 2,696,072 to 2,809,200 bp) contains the gene Vradi07g01630, which was annotated as the ammonium transport protein (AMT). The associated region in chromosome 9 (position 19,390,227 bp to 20,321,817 bp) contained the genes Vradi09g09510 and Vradi09g09600, annotated as OsGrx_S16-glutaredoxin subgroup II and dnaJ domain proteins respectively. These proteins were reported to have functions related to salt-stress tolerance.

Tomato (Solanum lycopersicum L.) is an economically important crop worldwide, particularly in tropical and subtropical regions. However, production is significantly and increasingly affected by the impacts of climate change, including heat and drought stress and emerging pests and diseases. This study specifically evaluated the effects of heat stress on root and shoot morphology, photosynthesis, and yield traits in five tomato genotypes, to identify the characteristics that differentiate heat tolerance from susceptibility. Heat stress experiments were conducted in a polyhouse, one during the summer under high temperatures, with a non-stress trial during the winter under conducive natural conditions. Significant reductions in yield, root traits and photosynthesis were observed across all genotypes under heat stress. However, the genotype MG785-1 maintained a relatively higher yield (298.01 ± 25.1 g), a 37.7% reduction compared to non-stress conditions, while CLN4786F1 showed resilience with a 32.3% decrease compared to its non-stress harvest index. Root dry weight (5.91 ± 0.53 g in MG785-1) and root shoot ratio (0.19 ± 0.01 in MG785-1) were identified as key traits for heat tolerance. Physiological traits, such as photosynthetic rate (11.71 ± 1.61 µmol CO₂ m⁻² s⁻¹ in MG785-1), were critical for maintaining growth under heat stress. In contrast, the heat-sensitive genotype CLN3961D exhibited a significant decline in yield and physiological performance. Root dry weight and root to shoot ratio were key indicators for heat tolerance, while the photosynthetic rate was critical for maintaining plant growth under stress. These findings underscore the importance of integrated root and physiological traits, providing valuable insights for breeding climate-resilient tomato varieties.

Single nucleotide polymorphism (SNP) markers are the method of choice for genetic analyses including diversity and quantitative trait loci (QTL) studies. Marker validation is essential for QTL studies, but the cost and workload are considerable when large numbers of markers need to be verified. Marker systems with low development costs would be most suitable for this task. We have tested allele specific polymerase chain reaction (PCR), tetra markers and a genotyping tool based on the single strand specific nuclease CEL-I to verify randomly selected SNP markers identified previously either with a SNP array or by genotyping by sequencing in rice and mungbean, respectively. The genotyping capacity of allele-specific PCR and tetra markers was affected by the sequence context surrounding the SNP; SNPs located in repeated sequences and in GC-rich stretches could not be correctly identified. In contrast, CEL-I digestion of mixed fragments produced from test and reference DNA reliably pinpointed the correct genotypes, yet scoring of the genotypes became complicated when multiple SNPs were present in the PCR fragments. A cost analysis showed that as long the sample number remains small, CEL-I genotyping is more cost-effective than tetra markers. CEL-I genotyping performed better in terms of genotyping accuracy and costs than tetra markers. The method is highly useful for validating SNPs in small to medium size germplasm panels.

Background: High temperature severely limits tomato reproductive development and yield, particularly in tropical production systems. Pollen viability and fruit set are commonly used as indicators of reproductive heat tolerance, but much of the supporting evidence has been obtained under controlled conditions. Their relevance to breeding under variable open-field environments remains less clear. This study investigated reproductive performance and its genetic basis under open-field heat stress using a multi-parent advanced generation inter-cross (MAGIC) population. Results: We developed a MAGIC population from eight Solanum lycopersicum parents combining heat tolerance and multiple disease resistances and evaluated 262 F _5:6 lines under natural open-field heat stress. Flower number showed the highest heritability (0.64), followed by pollen viability (0.56), fruit number (0.48), and days to flowering (0.25), whereas fruit set showed negligible heritability (<0.01). Despite its moderate heritability, pollen viability was only weakly correlated with fruit set ( r = 0.22). In contrast, fruit number was strongly correlated with fruit set ( r = 0.86), supporting fruit number as a practical selection criterion for reproductive performance under open-field heat stress. Restriction enzyme-associated DNA sequencing generated 16,350 high-quality SNPs for genome-wide association analysis, which identified multiple QTLs for reproductive traits, several overlapping previously reported loci. A region on chromosome 6 at approximately 31–33 Mb was particularly notable because it was associated with multiple reproductive traits and coincided with a previously reported heat-responsive QTL region. Candidate-gene analysis highlighted floral developmental regulation, represented by positional candidates SlAGO7 , ENO , and SlWUS , and cellular and protein homeostasis, supported by direct candidates including MON1, ECM29, and ubiquitin-related genes. Conclusions: Selection criteria established under controlled environments may not fully predict reproductive performance under open-field heat stress. Fruit number provides an integrative and moderately heritable indicator of realized reproductive success under field conditions. The identified QTLs and candidate genes provide targets for validation and development of heat-tolerant tomatoes adapted to tropical open-field production.

Tomato (Solanum lycopersicum) is an essential vegetable crop cultivated worldwide, but its production is highly vulnerable to tomato yellow leaf curl disease (TYLCD), which is transmitted by whiteflies (Bemisia tabaci). Management strategies typically focus on controlling either the virus or its vector. This study evaluates the effectiveness of multi-disease and insect-resistant tomato lines, developed by the World Vegetable Center (WorldVeg), which integrate Ty-1/Ty-3 genes for virus resistance and WF2-10 and WF3-09 genes for whitefly resistance. Virus accumulation, whitefly settling behavior, and adult mortality were assessed among multi-resistant lines, a Ty-resistant line, a whitefly-resistant line, and a susceptible check using preference bioassays, controlled inoculation experiments, and acylsugar quantification. Multi-resistant lines exhibited significantly higher acylsugar concentrations, reduced whitefly preference for settling, and increased whitefly adult mortality. Additionally, these lines displayed less severe disease symptoms and lower virus accumulation over time than Ty-resistant, whitefly-resistant, and susceptible controls. These findings highlight the superior efficacy of combined virus and vector resistance in mitigating tomato yellow leaf curl Thailand virus (TYLCTHV) transmission. This research underscores the importance of integrated genetic resistance as a key element of sustainable integrated pest management strategies, offering an environmentally friendly solution for safeguarding global tomato production.