Genetic variability in the Solanum nigrum L. complex and related species in South Africa

[摘要] English: Solanum nigrum L. and its related species can play a significant role in the foodsupply and nutrition of people in subsistence farming societies in Africa.- The objectives of this study were to conduct morphological trials on the parentmaterial and progeny and to determine heterosis and correlation of the progeny toidentify desirable characters that can be used in further breeding studies. Theidentification of the species was confirmed with the help of cytogenetics and. thecrossability of five species was investigated. The genetic relationships between thedifferent species and progeny were established. The total protein percentaqe, sugarcontent and pH of the different parental species was also determinate.- Seeds were obtained from several sources and seedlings were grown in a heatcontrolledglasshouse. Established plants were planted out in a glasshouse and twofield locations, these plants were used in the various investigations. The experimentaldesigns were complete randomized blocks with three or four replications.- The 15 morphological characters studied were subjected to an ANOVA. andsignificant differences were found between the accessions tested.- Cytological analyses were carried out and regard to the chromosome numbers thespecies seem to fit into the normal euploid series.- The ANOVA on the parents and progeny showed significant difference reflecting theextensive genetic differences between them. Solanum scabrum was an excellentparent and selections for characteristics like fruit per bunch and fruit size should leadto improved plants.- AFLP markers were used to distinguish polymorph isms between 14 species in thisstudy. Three primer combinations between ECOR I and MSE, were used and multiplepolymorph isms (62%) were detected.- Seven independent sequences and their reverse sequences were selected for useas primers in the SSR study. The genetic distance value amongst the species-andtheir progeny indicates the diversity but close relationship among the species tested.- The young leaves and fruit of the parental species used in the crossing study wereused in the assessments of the protein percentage, sugar and acid content of theplants.- The protein percentages were in most cases higher in the fruit than the leaves exceptfor Solanum scebrum; one of the species often used as leafy vegetable in Africa.- The TSS value in the fruit juice was inversely proportional to the size of the fruit.- The Solanum nigrum complex and related species is a rich, untapped source ofcharacteristics and could be used to improve the crop and probably other species inthe Solanaceae family.

[发布机构] University of the Free State