Development of microsatellite markers for Puccinia psidii, a rust fungus threatening ohia

(Metrosideros polymorpha) and other Myrtaceae in Hawaii

Shaobin Zhong and Baojun Yang

Department of Plant & Environmental Protection SciencesUniversity of Hawaii at Manoa

Honolulu, Hawaii

Life cycle and host range of Puccinia psidii

Host range: 20 genera and 71 species from Myrtaceae: Eucalypteae, Leptospermeae, Melaleuceae, Metrosidereae, Myrteae, Syncarpieae and Syzygieae (Glen et al. 2007)

(Glen M et al. 2007. Australasian Plant Pathology 36: 1–16)

origin

1977

2005

Origin and Distribution of Puccinia psidii

2005

Puccinia psidii in Hawaii

Rhodomyrtus tormentosaMetrosidero polymorpha

Eugenia koolauensis Melaleuca quinquenervia

Ohia is often one of the first plants to colonize new lava flows and is the major component in Hawaiian forest

Photo by C. Elevitch

The native Hawaiian honeycreeper ‘apapane on an ‘Ohi‘a lehua

Questions to be answered:

How many races (or strains) have been introduced into Hawaii?

Where were these races from?

SSR-enriched DNA library

DNA sequencing

Primer design

Evaluation of SSR markers

Population genetics

216 clones

80 primer pairs

15 SSRs

1 2 4 5 6 7 8 10 12 13 14 15 16 17 19 20 22 23 24 C

HI Florida HI HIBrazil

PsSSR12

1 2 4 5 6 7 8 10 12 13 14 1516 17 19 20 22 23 24 C

HI Florida HI HIBrazil

PsSSR195

1 2 4 5 6 7 8 10 12 13 14 1516 17 19 20 22 23 24 C

HI Florida HI HIBrazil

PsSSR208

100

85

100

100

93

Dendrogram based on 71 alleles from 15 SSR loci

Summary:

Fifteen microsatellite markers were developed

Seventy one alleles were identified among 19 isolates analyzed

Three genotypes found in four isolates from Florida and two genotypes detected in four Brazil isolates

Only one genotype was found in 12 Hawaiian isolates

Acknowledgements:

Acelino Alfenas (Federal University of Viosa, Brazil)

Robert Hauff (Hawaii Department of Agriculture, Hawaii)

Eloise Killgore (Hawaii Department of Agriculture, Hawaii)

Min Rayachhetry (US Forest Service, Florida)

Les Szabo (CDL-USDA, Minnesota)

Janice Uchida (University of Hawaii, Hawaii)