Host–pathogen interaction between Phytophthora infestans and Solanum nigrum, S. villosum, and S. scabrum

Abstract

Potato and tomato are the two major hosts for Phytophthora infestans causing late blight. The susceptibility of leaves and whole plants of Solanum nigrum, S. villosum, and S. scabrum to infection by P. infestans was tested under laboratory conditions. Out of 39 plants representing 38 different S. nigrum accessions, 16 were highly resistant (seven accessions did not show any symptoms of infection, nine were highly resistant showing necrotic lesions in the place of infection), and 23 plants of S. nigrum were colonized by, at least, 1 of the 2 isolates of P. infestans (17 accessions were infected with two P. infestans isolates, and 6 accessions showed different reactions depending on the isolate used for inoculation). Three accessions of S. villosum, and one accession of S. scabrum were tested and did not show any symptoms of infection. The majority of S. nigrum accessions infected by P. infestans in a detached leaf assay were also infected in the whole plant assay. The reaction of field-and greenhousegrown plants to inoculation with P. infestans in detached leaf assays was similar, but in some cases leaves from field-grown plants reacted as resistant in comparison with the leaves from greenhouse-grown plants, which were susceptible.

Accelerated cloning of a potato late blight–resistance gene using RenSeq and SMRT sequencing

“…However, large copy numbers and highly repetitive coding sequences impair accurate de novo assembly of complete NLR genes using short reads 4,8 Many Solanum species have been assessed for genetic variation in resistance to P. infestans, but resistance is rare 3 . The hexaploid S. nigrum is reported as resistant, and S. americanum is a likely diploid ancestor of S. nigrum 9 . To clone novel Resistance to Phytophthora infestans (Rpi) genes from the wild potato relative S. americanum, we screened thirteen diploid S. americanum accessions from three European seed collections for late blight resistance (Supplementary Table 1).…”

Resistance to Phytophthora Infestans in Three Solanum Nigrum F3 Families

“…A susceptible to P. infestans and three resistant S. nigrum accessions (Table 1) were selected as the parental forms from the work of Lebecka (2008). They were of diverse origins and they differed qualitatively in late blight resistance.…”

“…Later, infected plants of S. nigrum were found in The Netherlands (Flier et al 2003) and in Wales (Deahl et al 2004). Lebecka (2008) has tested 38 accessions of S. nigrum of diverse origins by laboratory tests for late blight resistance. She has used two P. infestans isolates and 15 S. nigrum accessions have been scored as highly resistant to both of them showing either no symptoms of disease or necroses caused by a hypersensitivity response.…”

“…She has used two P. infestans isolates and 15 S. nigrum accessions have been scored as highly resistant to both of them showing either no symptoms of disease or necroses caused by a hypersensitivity response. One accession contained both a resistant and a susceptible plant, while the remaining 22 accessions have been infected with at least one of the two P. infestans isolates (Lebecka 2008). A resistant (N19) and a susceptible plant (#13) have been selected from this pool of S. nigrum accessions and crossed (Lebecka 2009).…”

“…The goal of this study was to evaluate resistance of three families of F 3 lines, originating from crosses between a susceptible and three different resistant S. nigrum accessions from the group described by Lebecka (2008). We included an F 3 family described earlier (Lebecka 2009), that was extended in number of lines from 15 to 106.…”