Preprint Article Version 1 This version is not peer-reviewed

Construction of a Single-Nucleotide Polymorphism Marker Based Quantitative Trait Loci Map and Validation of Resistance Loci to Bacterial Wilt (Ralstonia solanacearum) in Tomato

Version 1 : Received: 15 May 2019 / Approved: 16 May 2019 / Online: 16 May 2019 (10:35:18 CEST)

How to cite: Shin, I.S.; Hsu, J.C.; Huang, S.M.; Chen, J.R.; Wang, J.F.; Hanson, P.; Schafleitner, R. Construction of a Single-Nucleotide Polymorphism Marker Based Quantitative Trait Loci Map and Validation of Resistance Loci to Bacterial Wilt (Ralstonia solanacearum) in Tomato. Preprints 2019, 2019050207 (doi: 10.20944/preprints201905.0207.v1). Shin, I.S.; Hsu, J.C.; Huang, S.M.; Chen, J.R.; Wang, J.F.; Hanson, P.; Schafleitner, R. Construction of a Single-Nucleotide Polymorphism Marker Based Quantitative Trait Loci Map and Validation of Resistance Loci to Bacterial Wilt (Ralstonia solanacearum) in Tomato. Preprints 2019, 2019050207 (doi: 10.20944/preprints201905.0207.v1).

Abstract

Bacterial wilt (BW), caused by Ralstonia solanacearum is one of the major biotic factors limiting tomato production in the humid tropics. Pyramiding of resistance genes through marker-assisted selection is an efficient way to develop durable BW resistant cultivars. Tomato line ‘Hawaii 7996’ (H7996) is a stable and robust resistance source against various R. solanacearum strains. Major BW resistance quantitative trait loci (QTLs) Bwr-12 and Bwr-6, and several minor or strain specific QTLs have been coarse-mapped in this line, but none has been fine-mapped and validated. The objective of the current study was to construct a high density genetic map using single-nucleotide polymorphism (SNP) markers derived from genotyping-by-sequencing, fine-map Bwr-12 and Bwr-6 and determine the effects of these QTLs using a near isogenic line (NIL) population. A high density genetic map using 1,604 SNP markers with an average distance of 0.82 cM was developed for 188 F9 recombinant inbred lines derived from the cross H7996 × WVa700. A total of seven QTLs associated with BW resistance to race 1-phylotype I or/and race 3-phylotype II strains were located on chromosomes 6 (Bwr-6.1, 6.2, 6.3 and 6.4) and 12 (Bwr-12.1, Bwr-12.2 and Bwr-12.3) with logarithm of odds (LOD) scores of 6.2-15.6 and 6.2-31.1, explaining 14.2-33.4% and 15.9-53.9% of the total phenotypic variation contributed from H7996, respectively. To validate the genetic effects of the two QTL regions, a set of 80 BC3F3 NILs containing different sections of Bwr-6 with or without Bwr-12 was phenotyped for disease severity after challenge with either race 1-phylotype I Pss4 or race 3-phylotype II Pss1632 BW strains over two seasons. Bwr-6.1 specific to Pss4 and Bwr-6.3 specific to Pss1632 were mapped to an interval of 5.0 cM (P < 0.05) between 6_33,444,000_SLM6-47 and 6_33,868,000_SLM6-124 SNP marker, and to 2.7 cM (P < 0.01) between positions 6_35,949,000 _SLM6-107 to 6_36,750,000_SLM6-82 marker, respectively. In addition, the specific effect of Bwr-12 for resistance to Pss4 (LOD score of 5.8-16.1, P < 0.01) was confirmed and markers for this QTL have already been made available previously.

Subject Areas

bacterial wilt; Ralstonia solanacearum; genotype-by-sequencing; disease resistance; quantitative trait loci; Solanum lycopersicum

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.