Interval Mapping of Quantitative Trait Loci for Corky Ringspot Disease Resistance in a Tetraploid Population of Potato (Solanum tuberosum subsp. tuberosum)

Abstract

Corky ringspot disease (CRS) resistance is an ideal target trait for breeding using marker-assisted selection (MAS) due to the high variability in field disease incidence that complicates screening for resistance. To develop molecular marker(s) associated with CRS resistance, a linkage map was constructed for a tetraploid population of 92 genotypes in order to conduct quantitative trait locus (QTL) analysis. The population was tested for CRS resistance in an infested screening field for four years. Broad sense heritability and its standard error of CRS disease resistance were 0.80 (±0.16). A total of 892 AFLP, 95 SSR, and 5 SSCP markers were scored and used for testing marker-trait association. One major QTL that explained 43% of the phenotypic variation in CRS resistance was localized on chromosome IX, with flanking AFLP markers AAC-CGT-0347 and ACG-CTG-0588. A minor QTL that explained 12% of CRS resistance was also detected. This minor QTL was associated with distorted marker GGT-CAC-0259, which remained unlinked. Polygenetic nature of CRS resistance was explained by major and minor QTLs association. Conversion of the three AFLP markers associated with this quantitative trait to simple PCR markers will benefit resistance breeding by enabling MAS. ResumenLa resistencia a la mancha de anillo corchoso (CRS) es un carácter ideal para el mejoramiento mediante la selección asistida por marcador (MAS), debido a la gran variabilidad de la incidencia de la enfermedad en el campo, la misma que complica el tamizado para resistencia. Para desarrollar marcadores moleculares asociados con resistencia a CRS, se construyó un mapa de ligamiento para una población tetraploide de 92 genotipos, con el fin de realizar un análisis de locus de un carácter cuantitativo (QTL). La población fue probada para resistencia a CRS tamizando por cuatro años en un campo infestado. La heredabilidad en sentido amplio de la resistencia a CRS, y su error estándar, fue de 0.80 (±16). Un total de 892 marcadores AFLP, 95 SSR y 5 SSCP fueron tomados en cuenta y usados para probar la asociación marcador-carácter. Un QTL mayor que explicó el 43% de variación fenotípica en resistencia al CRS fue localizado en el cromosoma IX, con marcadores AFLP flanqueantes, AAC-CGT-0347 y ACG-CTG-0588. Un QTL menor que explicó el 12% de resistencia al CRS fue detectado también. Este QTL menor fue asociado con el marcador distorsionado CGT-CAC-0259, el cual permaneció sin ligamiento. La naturaleza poligenética de la resistencia al CRS fue explicado por la asociación de los QTLs mayor y menor. La conversión de los tres marcadores AFLP asociados con este carácter cuantitativo en marcadores simples PCR, beneficiará el mejoramiento para resistencia haciendo posible la aplicación de MAS.

Linkage Mapping and QTL Analysis of Agronomic Traits in Tetraploid Potato (Solanum tuberosum subsp. tuberosum)

“…The findings we have presented, along with the recent work of Bradshaw et al (2008), Khu et al (2008), and Sagredo et al (2006) have demonstrated both the challenges and the feasibility of studying potato genetics using tetraploid potatoes.…”

“…The fi ndings we have presented, along with the recent work of Bradshaw et al (2008), Khu et al (2008), and Sagredo et al (2006) have demonstrated both the challenges and the feasibility of studying potato genetics using tetraploid potatoes. We have provided corroborating evidence for the presence of foliage maturity QTL on chromosomes III and V; QTL for specifi c gravity and/or dry matter on chromosomes II, V, VIII, IX, and XI; and QTL for yield on chromosomes II, V, VI, and VIII.…”

“…de Bary] (reviewed in Haynes et al, 1998), and resistance to insect pests (Flanders et al, 1992;Yencho et al, 1996) all show a continuous distribution. Many potato mapping and/or quantitative trait loci (QTL) analysis studies have been published during the course of more than two decades (Bonierbale et al, 1988;Gebhardt et al, 1989;Bonierbale et al, 1994;Freyre and Douches, 1994;Schäfer-Pregl et al, 1998;Collins et al, 1999;Visker et al, 2005;Bradshaw et al, 2008;Khu et ) is one of the world's most important crops. Using a tetraploid population, we developed a linkage map using amplifi ed fragment length polymorphism and simple sequence repeat (SSR) markers, and searched for quantitative trait loci (QTL) via interval mapping and single-marker analysis of variance.…”

Identification of Aluminum Tolerance Quantitative Trait Loci in Tetraploid Alfalfa

“…The genotype 95‐608 is a genotype derived from the synthetic cultivar CUF 101 (Lehman et al, 1983). Several genetic linkage maps of tetraploid alfalfa (Julier et al, 2003; Robins et al, 2007; Sledge et al, 2005) and potato ( Solanum tuberosum L.) (Bradshaw et al, 2008; Khu et al, 2008; McCord et al, 2011) were generated using F 1 populations given the outcrossing and autotetraploid nature of these species. Theoretical models for gene segregation in F 1 populations of autotetraploid species were developed by Wu et al (2001) and Luo et al (2004).…”

“…Linkage and QTL analysis were performed using the TetraploidMap software (Hackett et al, 2007) previously used for mapping in tetraploid alfalfa (Julier et al, 2003; Robins et al, 2007, 2008) and tetraploid potato (Bradshaw et al, 2008; Khu et al, 2008). The parental genotypes were determined based on the observed parent and offspring marker score (Luo et al, 2000).…”