Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2003
Publication Date: 1/9/2004
Citation: Chung, S., Staub, J.E. 2004. Molecular phylogeny of cucumis species as revealed by ccssr marker sequence variation. [abstract]. Plant And Animal Genome Abstracts. Paper No. 221. p. 127. Interpretive Summary:
Technical Abstract: The genus Cucumis has been partitioned into two subgenera Cucumis (x = 7) and Melo (x = 12). To investigate phylogenetic relationships in this genus, five amplified fragments of consensus chloroplast simple sequence repeat markers (ccSSR4, 12, 13, 19, and 20) were sequenced using total DNA of thirteen African Cucumis species (x = 12) accessions, three Cucumis melo L. (x = 12) accessions, two Cucumis sativus L. (x = 7) accessions, and one Cucumis hystrix Chakr. (x = 12) accession. A Citrullus lanatus (Thunb.) Matsum. & Nakai (x = 11) accession was used as an outgroup. Sequence substitution variation (150 sites) was detected, and used in UPGMA cluster analysis. Subsequently, 80 informative sequence substitution variants were detected and employed in parsimony analysis to determine the evolutionary relationships. Both analyses revealed the existence of two major species clusters (i.e., a group of African Cucumis species and a group composed of C. melo, C. sativus, and C. hystrix species). In these analyses, C. ficifolius (2x) and C. aculeatus (4x) of the African Cucumis species clustered together. This result does not agree with a previous isozyme analysis, but does agree with the characterized chromosome homologies reported between these two species. The wild Cucumis species, C. hystrix, has a close relationship with C. sativus even though it has the same chromosome number as C. melo and the wild African Cucumis diploid species examined. A more complete genomic comparison is necessary to understand the evolutionary relationship between C. sativus and C. hystrix.