Soto Sedano, J. C. | bioRxiv Science

bioRxiv2026

Exploring the genetic architecture underlying dietary fiber content in Colombian Andean blueberry (Vaccinium meridionale Swartz)

Dietary fiber composition is a major determinant of fruit nutritional quality, yet its genetic basis remains poorly characterized in wild Vaccinium species. Here, we combined extensive phenotyping with a genome-wide association study (GWAS) to dissect the genetic control of dietary fiber traits in Colombian agraz (Vaccinium meridionale Swartz). Total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble dietary fiber (SDF), the SDF/IDF ratio, and maturity index (MI) were quantified in fruits from 119 genotypes, representing the most comprehensive evaluation of dietary fiber fractions in fresh Vaccinium fruit to date. GWAS mapped this phenotypic diversity to 24 QTLs distributed across 15 chromosomes, revealing a polygenic architecture underlying fiber-related trait. A TDF QTL (Chr41:26883013) directly co-localized with VaccDscaff31-augustus-gene-268.33, a 7-deoxyloganetin glucosyltransferase, embedded within a glycosyltransferase-rich LD block. IDF variation was associated with VaccDscaff33-processed-gene-116.2 (pectin methylesterase 15) while the SDF/IDF ratio co-localized with VaccDscaff55-augustus-gene-9.30, encoding a xyloglucan endotransglucosylase/hydrolase. Together, the integration of high-resolution phenotyping with QTL mapping connects natural variation in dietary fiber content and composition to specific biosynthetic, remodeling, and regulatory pathways, providing actionable molecular targets for marker-assisted and genomic selection aimed at improving nutritional quality, texture, and processing traits in Vaccinium breeding programs.

genetics↗

bioRxiv2019

NOVEL ORGAN-SPECIFIC GENETIC FACTORS FOR QUANTITATIVE RESISTANCE TO LATE BLIGHT IN POTATO

Potato, Solanum tuberosum, is one of the highest consumed food in the world, being the basis of the diet of millions of people. The main limiting and destructive disease of potato is late blight, caused by Phytophtora infestans. Here, we present a multi-environmental analysis of the response to P. infestans using an association panel of 150 accessions of S. tuberosum Group Phureja, evaluated in two localities in Colombia. Disease resistance data were merged with a genotyping matrix of 83,862 SNPs obtained by 2b-restriction site-associated DNA and Genotyping by sequencing approaches into a Genome-wide association study. We are reporting 16 organ-specific QTL conferring resistance to late blight. These QTL explain from 13.7% to 50.9% of the phenotypic variance. Six and ten QTL were detected for resistance response in leaves and stem, respectively. In silico analysis revealed 15 candidate genes for resistance to late blight. Four of them have no functional genome annotation, while eleven candidate genes code for diverse proteins, including one leucine-rich repeat kinase.

genetics↗