Genomic regions and candidate genes linked with Phytophthora capsici root rot resistance in chile pepper (Capsicum annuum L.)

Dennis N Lozada; Guillermo Nunez; Phillip Lujan; Srijana Dura; Danise Coon; Derek W Barchenger; Soumaila Sanogo; Paul W Bosland

doi:10.1186/s12870-021-03387-7

Genomic regions and candidate genes linked with Phytophthora capsici root rot resistance in chile pepper (Capsicum annuum L.)

BMC Plant Biol. 2021 Dec 18;21(1):601. doi: 10.1186/s12870-021-03387-7.

Authors

Dennis N Lozada^{1

2}, Guillermo Nunez³, Phillip Lujan⁴, Srijana Dura³, Danise Coon^{3

5}, Derek W Barchenger⁶, Soumaila Sanogo⁷, Paul W Bosland^{3

5}

Affiliations

¹ Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, 88003, USA. dlozada@nmsu.edu.
² Chile Pepper Institute, New Mexico State University, Las Cruces, NM, 88003, USA. dlozada@nmsu.edu.
³ Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, 88003, USA.
⁴ Extension Plant Sciences, Plant Diagnostic Clinic, New Mexico State University, Las Cruces, NM, 88003, USA.
⁵ Chile Pepper Institute, New Mexico State University, Las Cruces, NM, 88003, USA.
⁶ World Vegetable Center, Shanhua, Tainan, 74151, Taiwan.
⁷ Department of Entomology, Plant Pathology and Weed Science, New Mexico State University, Las Cruces, NM, 88003, USA.

Abstract

Background: Phytophthora root rot, caused by Phytophthora capsici, is a major disease affecting Capsicum production worldwide. A recombinant inbred line (RIL) population derived from the hybridization between 'Criollo de Morellos-334' (CM-334), a resistant landrace from Mexico, and 'Early Jalapeno', a susceptible cultivar was genotyped using genotyping-by-sequencing (GBS)-derived single nucleotide polymorphism (SNP) markers. A GBS-SNP based genetic linkage map for the RIL population was constructed. Quantitative trait loci (QTL) mapping dissected the genetic architecture of P. capsici resistance and candidate genes linked to resistance for this important disease were identified.

Results: Development of a genetic linkage map using 1,973 GBS-derived polymorphic SNP markers identified 12 linkage groups corresponding to the 12 chromosomes of chile pepper, with a total length of 1,277.7 cM and a marker density of 1.5 SNP/cM. The maximum gaps between consecutive SNP markers ranged between 1.9 (LG7) and 13.5 cM (LG5). Collinearity between genetic and physical positions of markers reached a maximum of 0.92 for LG8. QTL mapping identified genomic regions associated with P. capsici resistance in chromosomes P5, P8, and P9 that explained between 19.7 and 30.4% of phenotypic variation for resistance. Additive interactions between QTL in chromosomes P5 and P8 were observed. The role of chromosome P5 as major genomic region containing P. capsici resistance QTL was established. Through candidate gene analysis, biological functions associated with response to pathogen infections, regulation of cyclin-dependent protein serine/threonine kinase activity, and epigenetic mechanisms such as DNA methylation were identified.

Conclusions: Results support the genetic complexity of the P. capsici-Capsicum pathosystem and the possible role of epigenetics in conferring resistance to Phytophthora root rot. Significant genomic regions and candidate genes associated with disease response and gene regulatory activity were identified which allows for a deeper understanding of the genomic landscape of Phytophthora root rot resistance in chile pepper.

Keywords: Genotyping-by-sequencing; New Mexico RIL (NMRIL) population; Phytophthora root rot; QTL mapping; Single nucleotide polymorphisms.

MeSH terms

Capsicum / genetics*
Capsicum / microbiology*
Chromosome Mapping
Disease Resistance / genetics*
Genetic Markers
Genome, Plant
Genotyping Techniques
Phytophthora / physiology*
Plant Diseases / genetics*
Plant Diseases / microbiology*
Plant Roots / microbiology
Polymorphism, Single Nucleotide
Quantitative Trait Loci

Substances

Genetic Markers