title: Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species.
abstract: Chromosome substitution (CS) lines in plants are a powerful genetic resource for analyzing the contribution of chromosome segments to phenotypic variance. In this study, a series of interspecific cotton (Gossypium spp.) CS lines were used to identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode or fungal disease resistance traits. The CS lines were developed in the G. hirsutum L. TM-1 background with chromosome or chromosome segment substitutions from G. barbadense L. Pima 3-79 or G. tomentosum. Root-knot nematode (Meloidogyne incognita) and fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) (races 1 and 4) resistance alleles and quantitative trait loci (QTL) previously placed on cotton chromosomes using SSR markers in two interspecific recombinant inbred line populations were chosen for testing. Phenotypic responses of increased resistance or susceptibility in controlled inoculation and infested field assays confirmed the resistance QTLs, based on substitution with the positive or negative allele for resistance. Lines CS-B22Lo, CS-B04, and CS-B18 showed high resistance to nematode root-galling, confirming QTLs on chromosomes 4 and 22 (long arm) with resistance alleles from Pima 3-79. Line CS-B16 had less fusarium race 1-induced vascular root staining and higher percent survival than the TM-1 parent, confirming a major resistance QTL on chromosome 16. Lines CS-B(17-11) and CS-B17 had high fusarium race 4 vascular symptoms and low survival due to susceptible alleles introgressed from Pima 3-79, confirming the localization on chromosome 17 of an identified QTL with resistance alleles from TM1 and other resistant lines. Analyses validated regions on chromosomes 11, 16, and 17 harboring nematode and fusarium wilt resistance genes and demonstrated the value of CS lines as both a germplasm resource for breeding programs and as a powerful genetic analysis tool for determining QTL effects for disease resistance. CS lines carrying small alien chromosome segments with favorable QTL alleles could be used for effective introgression of biotic stress resistance or many other desirable traits by targeting gene interactions and reducing linkage drag effects.
authors.affiliation: USDA-ARS, PA, CSRL, Plant Stress and Germplasm Development Research, 3810 4th Street, Lubbock, TX, 79415, USA. Mauricio.Ulloa@ars.usda.gov.
authors.forename: M
authors.initials: M
authors.lastname: Ulloa
authors.affiliation: Department of Nematology, University of California, Riverside, CA, 92521, USA.|Currently at the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China.
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.affiliation: USDA-ARS, Mississippi State, MS, 39762, USA.
authors.forename: S
authors.initials: S
authors.lastname: Saha
authors.affiliation: Department of Plant Sciences, University of California-Davis, Five Points, CA, 93624, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Hutmacher
authors.affiliation: Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Stelly
authors.affiliation: USDA-ARS, Mississippi State, MS, 39762, USA.
authors.forename: J N
authors.initials: JN
authors.lastname: Jenkins
authors.affiliation: USDA-ARS, PA, CSRL, Plant Stress and Germplasm Development Research, 3810 4th Street, Lubbock, TX, 79415, USA.
authors.forename: J
authors.initials: J
authors.lastname: Burke
authors.affiliation: Department of Nematology, University of California, Riverside, CA, 92521, USA. Philip.roberts@ucr.edu.
authors.forename: P A
authors.initials: PA
authors.lastname: Roberts
mesh_terms: D000483:Alleles; D000818:Animals; D032461:Chromosomes, Plant; D003433:Crosses, Genetic; D060467:Disease Resistance / Q000235:genetics*; D005670:Fusarium; D005819:Genetic Markers; D003368:Gossypium / Q000235:genetics* / Q000382:microbiology / Q000469:parasitology; D018895:Microsatellite Repeats; D010641:Phenotype; D000069600:Plant Breeding; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology / Q000469:parasitology; D040641:Quantitative Trait Loci; D014431:Tylenchoidea
chemical_list: D005819:Genetic Markers
keywords: Alleles; Disease resistance; Nematode egg production; Pima cotton; Plant survival; QTL mapping; Quantitative trait loci; Resistance genes; Root galling index; Upland cotton; Vascular root staining