Labuschagne, M. T.Jacoby, Angeline2017-03-292017-03-292003http://hdl.handle.net/11660/6035English: Solanum nigrum L. and its related species can play a significant role in the food supply and nutrition of people in subsistence farming societies in Africa. - The objectives of this study were to conduct morphological trials on the parent material and progeny and to determine heterosis and correlation of the progeny to identify desirable characters that can be used in further breeding studies. The identification of the species was confirmed with the help of cytogenetics and. the crossability of five species was investigated. The genetic relationships between the different species and progeny were established. The total protein percentaqe, sugar content and pH of the different parental species was also determinate. - Seeds were obtained from several sources and seedlings were grown in a heatcontrolled glasshouse. Established plants were planted out in a glasshouse and two field locations, these plants were used in the various investigations. The experimental designs were complete randomized blocks with three or four replications. - The 15 morphological characters studied were subjected to an ANOVA. and significant differences were found between the accessions tested. - Cytological analyses were carried out and regard to the chromosome numbers the species seem to fit into the normal euploid series. - The ANOVA on the parents and progeny showed significant difference reflecting the extensive genetic differences between them. Solanum scabrum was an excellent parent and selections for characteristics like fruit per bunch and fruit size should lead to improved plants. - AFLP markers were used to distinguish polymorph isms between 14 species in this study. Three primer combinations between ECOR I and MSE, were used and multiple polymorph isms (62%) were detected. - Seven independent sequences and their reverse sequences were selected for use as primers in the SSR study. The genetic distance value amongst the species-and their 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 were used in the assessments of the protein percentage, sugar and acid content of the plants. - The protein percentages were in most cases higher in the fruit than the leaves except for 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 of characteristics and could be used to improve the crop and probably other species in the Solanaceae family.Afrikaans: Solanum nigrum L. en verwante spesies in die kompleks kan 'n noemenswaardige rol as voedingsbron speel vir mense in Afrika, veral vir die in klein boerdery gemeenskappe. - Die doel van die studie was: om morfologiese studies op die ouers en nageslag uit te voer; en om die heterose en korrelasie van die naqeslaq te bepaal om sodoende vas te stel watter eienskappe in 'n teelprogram gebruik kan word. Die spesies is deur middel van sitogenetiese studies ondersoek om hul positief te identifiseer en 'n kruisingsstudie tussen vyf spesies is uitgevoer. Die genetiese afstande en verwantskappe tussen die spesies is ook bepaal: Die totale protein, suiker en suur inhoud van die ouers is ook ondersoek. - Sade afkomstig van verskeie. bronne is ontkiem en die saailinqe is in 'n temperatuur. beheerde glashuis gekweek. Die volwasse plante wat in verskeie ondersoeke gebruik is was in die glashuis as ook in twee ander veld lokaliteite uitgeplant. Die eksperimentele ontwerp was 'n volledige gerandomiseerde blok ontwerp met.drie of vier herhalings. - Die 15 morfologiese karakters was onderhewig .aan 'n ANOVA .en betekenisvolle verskille.is tussen dieJynewaargeneem. - Sitologiese studies is op die ouer spesies, wat in die kruisingsstudie qebruik is. uitgevoer en met betrekking. tot die chromosoom. getalle kon die spesies in die normale euploid reeks ingedeel word. - Die ANOVA vir die ouers.en nageslag toon merkwaardige verskilleen dit dui dus op die genetiese verskille tussen die lyne. Solanum scarbrum was 'n uitstekende ouer en seleksies vir karakters soos vrugte per tros en vruggrootte kan tot verbeterde plante lei. - AFLP merkers is gebruik om die verskillende vlakke van polimorfisme tussen die 14 spesies te onderskei. Drie priemstuk kombinasies tussen ECOR I en MSE is gebruik en 62% polimorfismes is waargeneem. - Sewe onafhanklike priemstuk volgordes en hulomgekeerde volgordes is gebruik_in. die microsatelliet (SSR) studie. Die genetiese afstande tussen die spesies en hul nageslag dui diversiteit aan maar daar is tog 'n baie nou verwantskap tussen die ouer spesies. - Die protein persentasies in die jong blare en vrugte as ook die suiker inhoud en.suur gehalte van die vrugte is bepaal. Die protein persentasie was in die meeste gevalle hoër in die vrugte as in die blare behalwe vir Solanum scabrum, 'n spesie wat alreeds as blaargroente gebruik word. - Die suiker inhoud in die vrugte was omgekeerd eweredig aan die vruggrootte. - Die Solanum nigrum kompleks en verwante spesies is 'n ryk, maar onontginde bron en kan sekerlik gebruik word om hierdie gewas te verbeter en heel moontlik ook vir ander spesies in die familie Solanaceae.enAmplified Fragment Length PolymorphismCytogeneticDNA fingerprintingGenetic diversityHybridizationMorphological characterizationNutritional valueSimple Sequence RepeatsSolanum nigrum complexSolanum retroflexumSolanum nigrum -- South Africa -- GeneticsSolanum nigrum -- Breeding -- South AfricaThesis (Ph.D. (Plant Sciences (Plant Breeding))--University of the Free State, 2003ThesisUniversity of the Free State