Genetic variation among land races of Cucurbita moschata and inheritance of its fruit yield and quality

Abstract

English: Tropical pumpkin (Cucurbita moschata Duchsne) is one of the most important vegetable crops in Africa. Apart from its phylogenetic relationships with other members of the genus, little information is available for this species. This study explored the amount of genetic variation in Zambia and Malawi for possible use in breeding. UPGMA cluster analysis from 3~) polymorphic and 105 monomorphic DNA fragments amplified by 16 RAPD markers showed four clusters, with genotypes from Malawi mainly clustering in three clusters while all genotypes from Zambia and three from Malawi clustered in one cluster. Six land races from this classification were mated in a daillel fashion and parents and progeny evaluated for fruit yield and quality. Variety effects were significant for the time to female anthesis and first fruit maturity, the weight of the first fruit, mean fruit weight and soluble solids. These characters could be improved by selection. Only for soluble solids were the progeny as a set different from the set of parents. Both variety and specific heterosis were significant FOR some of these traits, offering opportunities for heterosis breeding.

Afrikaans: Tropiese pampoen (Cucurbita moschata Duchsne) is een van die mees belangrike groente gewasse in Afrika. Afgesien van die filogenetiese verwantskappe met ander lede van die genus, is daar min inligting heskikbaar van hierdie spesie. Hierdie studie het 'n ondersoek gedoen na die hoeveelheid genetiese variasie in Zambië en Malawi vir moontlike gebruik in teling. UPGMA groep analise van 39 polimorfiese en 105 monomorfiese DNA fragments gearnplifiseer deur 16 RAPD merkers het vier groepe aangetoon, met alle genotipes van Zambië en drie van Malawi in een groep. Ses landrasse van hierdie klassifikasie is gekruis in 'n dialleel analise en die ours en nageslag is gëëvalueer vir vrug opbrengs en kwaliteit. Variëteits effekte was betekenisvol vir die tyd tot vroulike antese en eerste vrug rypwording, die gewig van die eerste vrug, die gemiddelde vrug gewig en die oplosbare vastestowwe. Hierdie eienskappe kan deur seleksie verbeter word. Net vir oplosbare vastestowwe was die nageslag verskillend van die stelouers. Beide variëteit- en spesifieke heterose was betekenisvol vir sommige van hierdie eienskappe, wat moonlikhede skep vir baster teling.