Population Genetics of Puccinia coronata f. sp.
avenae
Hattie Dambroski and Martin CarsonHattie Dambroski and Martin CarsonUSDA-ARS
Cereal Disease LaboratorySaint Paul, MN
Oat Crown Rust
Puccinia Pathway
Objective
To study the diversity and population structure of Puccinia coronata.
• sexual populations in the north
• asexual populations in the south
•DNA isolated from germinated and non-germinated urediniospores
•Five DNA samples isolated from aeciospores
•41 dinucleotide microsatellites
•Target sequence (CA)n
•Highly Polymorphic, allelic diversity ranges from 2 to 22
Microsatellites
Populations
• Northern Populations• MN, ND, SD, WI, NE
• Southern Populations• NC, FL, LA, AL
• Texas
• California
• Foreign Populations• Brazil, Israel, Russia, Egypt, Australia, Mexico, Canada, Uruguay, Turkey, Argentina
Isolates
CA
TX
SD
ND MN
LAFL
NC
Surveyed 75 isolates so far
NE
WI
AL
Statistics
HO ranged from 0.014 to 0.973
HE from 0.166 to 0.742
11 loci are in Hardy-Weinberg equilibrium (P<0.05)
Preliminary Results
AMOVA showed most molecular variance within populations vs. among populations
Neighbor joining tree based on genetic distance
Tree Results
1.Group with little genetic differentiation forming between north, south and Texas populations (asexual pop.)
2.Northern aecial isolates form a group with greater genetic differentiation between isolates (sexual pop.)
3.California isolates forming own group with great genetic differentiation from other groups
Things yet to do…..
•Finish U.S. Isolates
•Screen Foreign Isolates
•Screen Markers on other Rust species
•Analyze data