Abstract

Low polymorphism in cultivated watermelon has been reported in previous studies, based mainly on US Plant Introductions and watermelon cultivars, most of which were linked to breeding programmes associated with disease resistance. Since germplasm sampled in a putative centre of origin in southern Africa may harbour considerably higher variability, DNA marker-based diversity was estimated among 81 seedlings from eight accessions of watermelon collected in Zimbabwe; five accessions of cow-melons (Citrullus lanatus var. citroides) and three of sweet watermelons (C. lanatus var. lanatus). Two molecular marker methods were used, random amplified polymorphic DNA (RAPD) and simple sequence repeats (SSR) also known as microsatellite DNA. Ten RAPD primers produced 138 markers of which 122 were polymorphic. Nine SSR primer pairs detected a total of 43 alleles with an average of 4.8 alleles per locus. The polymorphic information content (PIC) ranged from 0.47 to 0.77 for the RAPD primers and from 0.39 to 0.97 for the SSR loci. Similarity matrices obtained with SSR and RAPD, respectively, were highly correlated but only RAPD was able to provide each sample with an individual-specific DNA profile. Dendrograms and multidimensional scaling (MDS) produced two major clusters; one with the five cow-melon accessions and the other with the three sweet watermelon accessions. One of the most variable cow-melon accessions took an intermediate position in the MDS analysis, indicating the occurrence of gene flow between the two subspecies. Analysis of molecular variation (AMOVA) attributed most of the variability to within-accessions, and contrary to previous reports, sweet watermelon accessions apparently contain diversity of the same magnitude as the cow-melons.

Published in

Hereditas
2010, Volume: 147, number: 4, pages: 142-153
Publisher: WILEY-BLACKWELL PUBLISHING, INC

SLU Authors

• Mujaju, Claid

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

• Sehic, Jasna

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

• Werlemark, Gun

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

• Gustavsson, Larisa

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

• Fatih, Moneim

  • Department of Urban and Rural Development, Swedish University of Agricultural Sciences
    

• Nybom, Hilde

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Swedish Biodiversity Centre


Sustainable Development Goals

SDG2 End hunger, achieve food security and improved nutrition and promote sustainable agriculture


UKÄ Subject classification

Horticulture
Food Science


Publication identifier

DOI: https://doi.org/10.1111/j.1601-5223.2010.02165.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/60575