Fine mapping of the tomato yellow leaf curl virus resistance gene Ty-2 on chromosome 11 of tomato

Abstract

Resistances to begomoviruses, including bipartite tomato mottle virus and monopartite tomato yellow leaf curl virus (TYLCV), have been introgressed to cultivated tomato (Solanum lycopersicum) from wild tomato accessions. A major gene, Ty-2 from S. habrochaites f. glabratum accession “B6013,” that confers resistance to TYLCV was previously mapped to a 19-cM region on the long arm of chromosome 11. In the present study, approximately 11,000 plants were screened and nearly 157 recombination events were identified between the flanking markers C2_At1g07960 (82.5 cM, physical distance 51.387 Mb) and T0302 (89 cM, 51.878 Mb). Molecular marker analysis of recombinants and TYLCV evaluation of progeny from these recombinants localized Ty-2 to an approximately 300,000-bp interval between markers UP8 (51.344 Mb) and M1 (51.645 Mb). No recombinants were identified between TG36 and C2_At3g52090, a region of at least 115 kb, indicating severe recombination suppression in this region. Due to the small interval, fluorescence in situ hybridization analysis failed to clarify whether recombination suppression is caused by chromosomal rearrangements. Candidate genes predicted based on tomato genome annotation were analyzed by RT-PCR and virus-induced gene silencing. Results indicate that the NBS gene family present in the Ty-2 region is likely not responsible for the Ty-2-conferred resistance and that two candidate genes might play a role in the Ty-2-conferred resistance. Several markers very tightly linked to the Ty-2 locus are presented and useful for marker-assisted selection in breeding programs to introgress Ty-2 for begomovirus resistance.Electronic supplementary materialThe online version of this article (doi:10.1007/s11032-014-0072-9) contains supplementary material, which is available to authorized users.

Evaluation of tomato entries with different combinations of resistance genes to tomato yellow leaf curl disease in Tunisia

“…Ty‐2 is widely used by tomato breeders and there is some evidence suggesting that Ty‐2 enhances resistance of Ty‐3 (Yang et al. ) or Ty‐1 (Barbieri et al. ).…”

“…Ty-2 has provided effective resistance to some begomoviruses in Taiwan and India (Hanson et al 2000), but it does not hold against bipartite begomoviruses. Ty-2 is widely used by tomato breeders and there is some evidence suggesting that Ty-2 enhances resistance of Ty-3 (Yang et al 2014) or Ty-1 (Barbieri et al 2010). Barbieri et al (2010) gave evidence on effectiveness specificity of Ty-1 and Ty-2 genes according to TYLCV-Is strains: Ty-1 and Ty-2 responded differently if challenged with two apparently similar viruses, that is TYLCV-Is and TYLCSV.…”

A Major QTL Located in Chromosome 8 of Cucurbita moschata Is Responsible for Resistance to Tomato Leaf Curl New Delhi Virus

“…This gene family has been associated to different virus-resistance mechanisms. A MADS-box transcription factor was described as the Ty-2 candidate, involved in the tomato resistance to tomato yellow leaf curl virus (TYLCV) (Yang X. et al, 2014), and recently, a MADS-box gene has been reported to be upregulated in the Sw-7 resistance to tomato spotted wilt tospovirus (TSWV) (Padmanabhan et al, 2019). No SNPs with high-impact predicted effect were identified in CmoCh08G001760 between C. moschata accessions, but changes in 5 and 3 UTRs and a missense mutation with predicted moderate effect were polymorphic between resistant and susceptible accessions.…”

Molecular Markers for Selecting Diverse Disease Resistances in Tomato Breeding Programs

“…Recently, a gene responsible for Ty1 resistance was identified as a DFDGD-class RNAdependent RNA polymerase and was demonstrated to be allelic with Ty3 resistance (Verlaan et al 2013). Ty2 resistance originated from S. habrochaites "B6013" and was recently mapped to a 300-kb interval on chromosome 11 (Hanson et al 2000;Ji et al 2009a;Yang et al 2014). Ty4 was identified on chromosome 3 as an additional resistance locus in Ty3-carrying S. chilense "LA1932" and "LA2779" (Ji et al 2009b).…”