TITLE:
Localisation of Loci Involved in Resistance to Diaporthe toxica and Pleiochaeta setosa in White Lupin (Lupinus albus L.)
AUTHORS:
Rosy Raman, Cina Vipin, David J. Luckett, Raymond B. Cowley, Gavin J. Ash, John D. I. Harper, Andrzej Kilian, Harsh Raman
KEYWORDS:
L. albus, Genetic Diversity, Phomopsis Blight, Pleiochaeta Root Rot, DArT, Linear Regression Analysis, Genome-Wide Association Analysis
JOURNAL NAME:
Open Journal of Genetics,
Vol.4 No.3,
June
26,
2014
ABSTRACT: L.
albus is an annual grain-legume crop mainly grown for
high-protein fodder worldwide but also to produce large seeds for human
consumption as a snack-food. In order to make genetic gains in grain yield,
assessment of the genetic variation in the germplasm and identification of loci
associated with agronomic traits are essential. Phomopsis blight (PB) and
Pleiochaeta root rot (PRR), caused by the fungal pathogens Diaporthe toxica and, Pleiochaeta
setosa respectively, are two major yield-limiting diseases of the L. albus crop. The extent of genetic
diversity in 94 accessions of L. albus comprising: Australian and exotic cultivars, advanced breeding lines, and
landraces originating from 26 different countries was determined utilizing PCR-based
genic, and microarray-based Diversity Arrays Technology (DArT™), markers. All
accessions were evaluated for resistance to PB in two plant tissues (leaves and
stems) using either sprayed or injected spore inoculum. A subset of 58
accessions was further evaluated for resistance to PRR by growing seedlings in
spore-infested potting mix. The combined data of 724 (50 genic- and 674 DArT)
markers were used for cluster analysis. A subset of 324 markers with call rate
≥95% and predicted disease scores of different genotypes were used to identify
marker loci accounting for phenotypic variation in PB and PRR resistance using
linear regression analysis. Several markers showed significant association with
PB or PRR resistance at P