Phylogenetic analysis of the genus Sorghum based on combined sequence data from cpDNA regions and ITS generate well-supported trees with two major lineages.
OBJECTIVE
Wild Sorghum species provide novel traits for both biotic and abiotic stress resistance and yield for the improvement of cultivated sorghum. A better understanding of the phylogeny in the genus Sorghum will enhance use of the valuable agronomic traits found in wild sorghum. METHODS Four regions of chloroplast DNA (cpDNA; psbZ-trnG, trnY-trnD, trnY-psbM and trnT-trnL) and the internal transcribed spacer (ITS) of nuclear ribosomal DNA were used to analyse the phylogeny of sorghum based on maximum-parsimony analyses.


RESULTS
Parsimony analyses of the ITS and cpDNA regions as separate or combined sequence datasets formed trees with strong bootstrap support with two lineages: the Eu-sorghum species S. laxiflorum and S. macrospermum in one and Stiposorghum and Para-sorghum in the other. Within Eu-sorghum, S. bicolor-3, -11 and -14 originating from southern Africa form a distinct clade. S. bicolor-2, originally from Yemen, is distantly related to other S. bicolor accessions.


CONCLUSIONS
Eu-sorghum species are more closely related to S. macrospermum and S. laxiflorum than to any other Australian wild Sorghum species. S. macrospermum and S. laxiflorum are so closely related that it is inappropriate to classify them in separate sections. S. almum is closely associated with S. bicolor, suggesting that the latter is the maternal parent of the former given that cpDNA is maternally inherited in angiosperms. S. bicolor-3, -11 and -14, from southern Africa, are closely related to each other but distantly related to S. bicolor-2.
Ng'uni
Dickson
D
Department of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences, Box 101, SE23053 Alnarp, Sweden. dickson.nguni@gmail.com
Geleta
Mulatu
M
Fatih
Moneim
M
Bryngelsson
Tomas
T
D001483:Base Sequence; D017931:DNA Primers; D005231:Fatty Acids, Unsaturated / Q000235:genetics*; D017343:Genes, Plant; D010802:Phylogeny; D045868:Sorghum / Q000145:classification / Q000235:genetics*
D017931:DNA Primers; D005231:Fatty Acids, Unsaturated; C055648:9-(4-chlorophenyl)-7,7-dimethyl-5,8-nonadienoic acid