Taxonomic studies on Solanum section Solanum (Maurella)

Abstract

Various taxonomic methods are being used to clarify the systematics of Solanum section Solanum, the large and variable species group centring around the black nightshade, S. nigrum. To put the experimental work into perspective, a summary of former taxonomic treatments is given, together with an outline of the provisional taxonomic framework of the section, initially established from earlier classical studies, and supplemented by later experimental work. Experimentation with living populations has shown that Solanum taxonomy is complicated by several factors. In addition to the historical factors, phenotypic plasticity, genetic variation, the existence of a polyploid series, and the possibilities of interspecific hybridization accompanied by various pre‐ and post‐zygotic isolating mechanisms are dealt with. The various taxonomic categories attached to Solanum accessions during earlier classical studies derive support from the crossability behaviour of the taxa concerned. Morphological divergence is generally accompanied by genetical isolation which can manifest itself at any time between pollination and the maturation of the F2 progeny. Data from the hybridization studies, in which 14 diploid species, five tetraploid species, four hexaploid species and one octoploid taxon were used, are presented in detail.

THE BIOLOGY OF CANADIAN WEEDS.: 67. Solarium ptycanthum Dun., S. nigrum L. and S. sarrachoides Sendt.

“…Black nightshade seed has little or no dormancy once separated from the berry (Singh 1970;Holm et al 1977;Roberts and Lockett 1978). Roberts and Boddrell (1983) Edmonds (1977) and Rao (1981) produced artificial hybrids between black and hairy nightshades. In both cases the hybrids were also tetraploids with low pollen fertility.…”

Flora da Paraíba, Brasil: Solanum L. (Solanaceae)

“…Identificações e descrições -Realizaram-se estudos morfológicos para as identificações com amostras frescas, fixadas em FAA e conservadas em álcool a 70 o , e análise de exsicatas dos herbários JPB e EAN, ambos da Universidade Federal da Paraíba, e IPA, Empresa Pernambucana de Pesquisa de Agropecuária, complementados por observações de campo. Os estudos taxonômicos foram realizados com o apoio da bibliografia especializada (Sendtner 1846;Dunal 1852;Edmonds 1972;1977;Bohs 1994;Carvalho 1996;Knapp 2002;Mentz & Oliveira 2004;Agra 2004), complementados pela análise de espécimes e tipos dos herbários EAN, CEPEC, F, G, IPA, K, M, MAC, MG, MO, NY, P, R, RB, PEUFR, S, SP e SP, SPF, UB, US e W, relacionados de acordo com Holmgren et al (1990). As descrições de algumas espécies, cujo material encontrava-se estéril ou incompleto, foram complementadas pela análise de material adicional.…”

“…De acordo com Edmonds (1977) e D'Arcy (1991), Solanum americanum é uma espécie encontrada em todos os países de clima tropical e temperados mais quentes, onde foi introduzida da América do Sul. No Brasil, encontra-se amplamente distribuída, desde as regiões mais frias do Sul (Mentz & Oliveira 2004), até as mais quentes e secas do Nordeste.…”

Successful first and second backcrosses of S. nigrum (+) S. tuberosum somatic hybrids with both Solanum parents

“…The results of the P. infestans tests might indicate that one or more chromosomes were missing in the susceptible BC2 genotypes. It might also be possible that not all genomes of S. nigrum contribute to the resistance since S. nigrum is expected to be an allohexaploid (Edmonds 1979).…”