Genetic control and mapping of Solanum chilense LA1932, LA1960 and LA1971-derived resistance to Tomato yellow leaf curl disease

Abstract

Tomato yellow leaf curl disease (TYLCD) is caused by a complex of begomovirus. Breeding for resistance to this disease has mainly been based on Ty-1 gene, derived from Solanum chilense LA1969. Commercial varieties available to date still develop symptoms and suffer yield losses with high inoculum pressure and early infections. It is of interest to incorporate in breeding programs resistance from the different available sources. Lines with resistance to TYLCD derived from S. chilense accessions LA1932, LA1960 and LA1971 were previously developed. The objectives of this work were to study the genetic control of the resistance derived from these accessions and to map the resistance loci. Response to viral infection was assayed in segregating generations derived from these sources. Results obtained were compatible with a monogenic control of resistance. A total of 94 markers were used to locate the S. chilense introgressions in each of the lines. Only the presence of a large introgression in chromosome 6 was common to all lines. Analysis of recombinants allowed localizing the resistance loci in an interval of approximately 25 cM, also common to all five families. This interval includes the region to which two previously S. chilense-derived TYLCD resistance loci have been mapped, the Ty-1/Ty-3 region. This is the first report of LA1960 and LA1971-derived TYLCV resistance loci to be located on chromosome 6. Further work will be done to fine map the loci found in the present work, in order to determine if they are indeed located in the Ty-1/Ty-3 region.

Assessing the genetic variation of Ty-1 and Ty-3 alleles conferring resistance to tomato yellow leaf curl virus in a broad tomato germplasm

“…In a previous study, TYLCV resistance in S. chilense accessions LA1932, LA1960 and LA1971 was studied and shown to be controlled by a major dominant gene located on chromosome 6 (Pérez de Castro et al 2013 ), indicating that the causal genes in these accessions are likely allelic to Ty - 1 . To further verify the localization of the causal genes in the Ty - 1 interval, fine-mapping was performed in this study using F 2 and backcross mapping populations derived from these three accessions (Table 1 , Figure S2).…”

“…An alternative possibility is that line 1594 may carry, in addition to a Ty - 1 allele, another TYLCV resistance gene derived from LA1971. It is worthwhile to note that the LA1971-derived parental line of our mapping population and line 1594 used in the VIGS experiments in this study are different, but “sisters” of the lines described in the previous paper of Pérez de Castro et al ( 2013 ). Checking the LA1971 introgressions in this line, it appeared that line 1594 has multiple introgressions located on chromosomes 6, 7, 10 and 11 (see Fig.…”

“…In S. chilense , multiple accessions have been described as symptomless after TYLCV inoculation. For some accessions, including LA1960, LA1971 and LA1938, the causal genes for resistance were mapped to chromosome 6 in the chromosome region where Ty - 1 is located, suggesting allelism to Ty - 1 / Ty - 3 (Pérez de Castro et al 2013 ; Agrama and Scott 2006 , Hutton and Scott, unpublished data). For other accessions, the causal genes have not been mapped (Pico et al 1999 ).…”

Salicylic acid differently impacts ethylene and polyamine synthesis in the glycophyte Solanum lycopersicum and the wild‐related halophyte Solanum chilense exposed to mild salt stress

“…This self‐incompatible perennial was historically included in the polymorphic Solanum peruvianum but is now considered as a distinct species found in a geographically restricted area and characterized by narrow ecological niches (Igic et al , Nakazato et al , Tellier et al ).This wild tomato species is able to grow in diverse environments and to cope with many biotic and abiotic constraints (Martínez et al , ). It is commonly considered as a valuable source of genes for resistance to viruses such as Pseudomonas syringae (Thapa et al ) or tomato yellow leaf curl disease (Pérez de Castro et al ). Surprisingly, physiological basis of salt resistance in S. chilense has received only minor attention until now in comparison to other salt‐tolerant wild‐relatives, such as Solanum cheesmanii, Solanum pimpinelifolim and Solanum pennellii (Mittova et al , Albacete et al , Gálvez et al , Almeida et al ).…”

Aprovechamiento de las especies Solanum peruvianum en la mejora del tomate

“…In most assays, only asymptomatic plants have been classified as resistant (Hassan et al, 1984;Pilowsky and Cohen, 1990). In contrast, other authors have established the limit score in slight symptoms that would not produce appreciable yield losses (Kasrawi and Mansour, 1994;Pérez de Castro et al, 2013). Nevertheless, several factors, such as plant age at the time of inoculation, inoculation pressure, and growing conditions can affect the responses to begomovirus infection .…”