Solanum lycopersicoides is a valuable genetic resource for tomato (Lycopersicon esculentum) genetic improvement. However, there are few reports on its agronomic traits such as disease resistance and cold tolerance. In this paper, the resistance to cucumber mosaic virus (CMV) and leaf mold (Cladosporium fulvum Cooke) and cold tolerance of five lines of S. lycopersicoides were studied through investigation of disease inoculation and electrolyte leakage analysis. The results showed that S. lycopersicoides was highly resistant or immune to CMV and leaf mold and more tolerant to low temperature than L. esculentum. This study is helpful for the genetic improvement of tomato by using S. lycopersicoides as breeding materials.
The chilling tolerance of commercial Lycopersicon esculentum cultivars (H2653, H722), Solanum lycopersicoides, an F1 hybrid of S. lycopersicoides × Sub-Arctic Maxi, and 25 BC2F2 lines of L. hirsutum × H722 (backcrossed twice to H722) was evaluated using a chlorophyll fluorescence assay. The ratio of the initial to the peak fluorescence (Fo: Fp) measured from fully expanded leaves was chosen as an indicator of plant health. Chilling induced an increase in Fo: Fp that was correlated with the sensitivity of the plant to low-temperature stress. Values of Fo: Fp remained low for cold-treated S. lycopersicoides and the F1 hybrid, which showed few symptoms of chilling-related damage, whereas the commercial cultivars, which were essentially intolerant to low temperatures, had large increases in Fo: Fp. A full range of Fo: Fp values was measured in the 25 BC2F2 lines, indicating that some chilling tolerance from the L. hirsutum parent was expressed by plants in these populations.
The C.M. Rick Tomato Genetic Resources Center (TGRC) is a genebank of wild relatives, monogenic mutants, and miscellaneous genetic stocks of tomato. The wild species group includes representatives of all nine Lycopersicon spp., as well as four related Solanum species. One of the roles of the TGRC has been to foster the use of the widest available gene pool for tomato researchers. The wild nightshade Solanum lycopersicoides possesses a number of potentially useful traits, but has been untapped by breeders because of sterility and incompatibility barriers. We are using molecular markers to identify alien chromosomal segments introgressed from S. lycopersicoides into tomato. This project involves development of RFLP, RAPD, and isozyme marker linkage maps and their use in selection of homozygous segmental substitutions in backcross inbred progenies. In this fashion, a large proportion of the S. lycopersicoides genome has been integrated into the cultivated tomato. This study has also provided information on the nature of sterility and novel variation in hybrid derivatives.
Intact plants of four Lycopersicon species, Solanum lycopersicoides Dun. and a L. esculentum Mill. × S. lycopersicoides intergeneric hybrid at the four- to 11-leaf developmental stage were subjected to temperatures of 20° or 2.5°C for 72 hr. Plants were assayed for chilling injury by a visual rating of damage on specified leaflets (VRL), chlorophyll fluorescence (CF), electrolyte leakage (EL), and a visual rating of plants (VRP). Correlations of genotypic effects were significant between a) CF and VRL, b) CF and VRP, c) VRL and VRP, and d) VRP and EL. Correlations of the temperature × genotype interactions were highly significant between a) CF and VRL, b) CF and VRP, and c) VRL and VRP. CF was the most precise assay to quantify chilling injury. The means for CF for each of five leaflets from a single leaf produced similar separation of genotypes. Chilling resistance of an intergeneric hybrid between sensitive L. esculentum Mill. cv Sub-Arctic Maxi and resistant S. lycopersicoides suggested dominant, nuclear gene control.
Accessions of several wild tomato species [Lycopersicon hirsutum H. and B. (LA 1363 and LA 1777), L. chilense Dun. (LA 1969 and LA 1971), and Solanum lycopersicoides Dun. (LA 1964)] were examined for cold tolerance and compared to the fast germination of L. esculentum Mill. PI 341988 and to the normal germination of ‘UC82B’. The wild accessions were collected above 3000 m and presumed to be cold-tolerant because of natural habitat. A number of characteristics, including germination, emergence, chlorophyll fluorescence, electrolyte leakage, and plastochron index were used to evaluate chilling resistance. PI 341988 germinated faster than the other genotypes at temperatures above 10°C, but germination of this accession virtually ceased below 10°. The high-altitude accessions continued to germinate, albeit at a reduced rate, below 10°. Growth rates at 12°/6° (day/night) were compared to growth at 24°/18° and were found to be greater in the high-altitude accessions than ‘UC82B’ The reduction in chlorophyll fluorescence when leaf disks were exposed to 1° was less in the high-altitude accessions than in ‘UC82B’, indicating less effect of this temperature on photosynthesis in the wild species. Electrolyte leakage was greater in ‘UC82B’ and LA1777 (L. hirsutum) than high-altitude accessions of L. chilense and S. lycopersicoides, but evidence is presented that this method is not reliable in screening for cold tolerance. Crosses were made between ‘UC82B’ and the wild species, and segregating populations were screened using the methods mentioned above. In each population, there were plants that showed cold resistance similar to the wild parent, suggesting the possibility of developing cold-tolerant cultivars.
resistance gene Mi Mol. Plant Microbe Interact. 13 1130 1138 Canady, M.A. Ji, Y.F. Chetelat, R.T. 2006 Homeologous recombination in Solanum lycopersicoides introgression lines of cultivated tomato Genetics
Informatics Conf. p. 36. (abstr.). 3 Dec. 2020. < http://cbr.jic.ac.uk/dicks/software/threadmapper > Chetelat, R.T. Meglic, V. Cisneros, P. 2000 A genetic map of tomato based on BC 1 Lycopersicon esculentum x Solanum lycopersicoides reveals overall
-015-1444-1 Chetelat, R.T. Meglic, V. Cisneros, P. 2000 A genetic map of tomato based on BC 1 Lycopersicon esculentum x Solanum lycopersicoides reveals overall synteny but suppressed recombination between these homeologous genomes Genetics 154 857 867
from Solanum lycopersicoides Dunal accession LA2408 and has been mapped to chromosome 10 of cultivated tomato. It is not known whether Abg resides at the same locus as Aft , but it is located on the same chromosome arm. In crosses with cultivated
.H. 2014 Resistance to Botrytis cinerea in Solanum lycopersicoides involves widespread transcriptional reprogramming BMC Genomics 15 334 Trotel-Aziz, P. Couderchet, M. Vernet, G. Aziz, A. 2006 Chitosan stimulates defense reactions in grapevine leaves