A multilocus phylogeny of the non-photosynthetic parasitic plant Cistanche (Orobanchaceae) refutes current taxonomy and identifies four major morphologically distinct clades.

Phylogenetic relationships of and within non-photosynthetic parasitic lineages are notoriously poorly known, which negatively affects our understanding of parasitic plants. This is also the case for Cistanche (Orobanchaceae), an Old World genus with about two dozen species, whose relationships have not yet been addressed using molecular phylogenetic approaches. Here we infer phylogenetic relationships within the genus, employing a taxonomically and geographically broad sampling covering all previously distinguished infrageneric groups and most of the currently recognized species. A combined matrix of three plastid markers (trnL-trnF, including the trnL intron and the intergenic spacer (IGS), trnS-trnfM IGS and psbA-trnH IGS) and one nuclear marker (ITS) was analyzed using maximum parsimony, maximum likelihood and Bayesian inference. Cistanche falls into four well-supported and geographically differentiated clades: East Asian Clade, Northwest African Clade, Southwest Asian Clade and Widespread Clade. Of those, only the East Asian Clade corresponds to a previously recognized taxonomic section, whereas the others either contain members of two or three sections (Widespread Clade and Southwest Asian Clade, respectively) or have not been taxonomically recognized so far (Northwest African Clade). Whereas the Southwest Asian Clade exhibits strong phylogenetic structure among and partly within species (the East Asian Clade and the Northwest African Clade are monospecific), phylogenetic resolution within the Widespread Clade is often low and hampered by discrepancies between nuclear and plastid markers. Both molecular and morphological data indicate that species diversity in Cistanche is currently underestimated.

Genome Wide Association Study of Karnal Bunt Resistance in a Wheat Germplasm Collection from Afghanistan.

Karnal bunt disease of wheat, caused by the fungus Neovossia indica, is one of the most important challenges to the grain industry as it affects the grain quality and also restricts the international movement of infected grain. It is a seed-, soil- and airborne disease with limited effect of chemical control. Currently, this disease is contained through the deployment of host resistance but further improvement is limited as only a few genotypes have been found to carry partial resistance. To identify genomic regions responsible for resistance in a set of 339 wheat accessions, genome-wide association study (GWAS) was undertaken using the DArTSeq® technology, in which 18 genomic regions for Karnal bunt resistance were identified, explaining 5-20% of the phenotypic variation. The identified quantitative trait loci (QTL) on chromosome 2BL showed consistently significant effects across all four experiments, whereas another QTL on 5BL was significant in three experiments. Additional QTLs were mapped on chromosomes 1DL, 2DL, 4AL, 5AS, 6BL, 6BS, 7BS and 7DL that have not been mapped previously, and on chromosomes 4B, 5AL, 5BL and 6BS, which have been reported in previous studies. Germplasm with less than 1% Karnal bunt infection have been identified and can be used for resistance breeding. The SNP markers linked to the genomic regions conferring resistance to Karnal bunt could be used to improve Karnal bunt resistance through marker-assisted selection.