The University of Western Australia

Monica Kehoe School of Plant Biology and The UWA Institute of Agriculture, Faculty of Science

Monica completed a Bachelor of Science with a major in

Microbiology at The University of Melbourne, and moved to

Western Australia in 2005 to work in Plant Virology at the

Department of Agriculture and Food WA (DAFWA).

Her fascination with (plant) viruses and her interest in research

led to an honours degree at Murdoch university, where she

worked on resistance phenotypes to Turnip mosaic virus in

mustard species.

She commenced her PhD at UWA in 2011, working on Black Pod

Syndrome in lupins. She continues to be based at DAFWA where

she has participated in a wide range of research projects,

including viruses in broadacre and agricultural crops.

The University of Western Australia

THE UWA INSTITUTE OF AGRICULTURE

Postgraduate Showcase 2013: Frontiers in Agriculture

Unravelling the cause of Black Pod Syndrome of narrow-leafed lupins Monica Kehoe

The University of Western Australia

Acknowledgements

Supervisors: Roger Jones and Bevan Buirchell DAFWA: Brenda Coutts, Stuart Vincent and Eva Gajda GRDC for funding (GRDC supported PhD Project GRS10039)

The University of Western Australia

Australia grows 85% of global crop, WA 80% of national crop

2005-2010 average area was

540,000 ha, av. yield 1.2 t/ha Based on soils and climate, 1.6

million ha possible Black Pod Syndrome major reason

yields below potential, especially in south coast zone

Lupin production zones

The University of Western Australia

Pods, especially primaries, turn black or dark brown producing few or no seeds

Causes other than virus now

ruled out BPS and late Bean yellow

mosaic virus (BYMV) infection coincide

Black Pod Syndrome (BPS)

Differences between cultivar plots

The University of Western Australia

BYMV in narrow-leafed lupins

Early infection Spread by aphids Nearby pasture Necrosis, shepherds crook,

death Nbm-1 gene

Typical early season BYMV symptoms

The University of Western Australia

Serological (ELISA) Molecular (PCR)

Green leaf Necrotic stem

The University of Western Australia

Initial glasshouse studies reproduced BPS in plants inoculated with BYMV

The University of Western Australia

2011 survey

5 locations Testing by ELISA and PCR 133 plants – 72 symptomatic Multiple samples per plant - 314 Best spot to test = stem, below black pods

BPS symptomatic samples

Typical BPS in the field

The University of Western Australia

Section of plant Number

of samples

ELISA PCR

POTY BYMV POTY BYMV

Stem (near black pods) 72 75% 83% 99% 82%

Stem (mid) 72 33% 61% 89% 58%

Leaf 48 2% 19% 96% 48%

The University of Western Australia

Reproducing BPS in the glasshouse

Mandelup vs Jenabillup 8 plants per cultivar inoculated every two weeks Infection before flowering = typical BYMV symptoms:

Test Test vs Control

The University of Western Australia

Infection at primary pod stage – black pod and plant death

The University of Western Australia

Infection after 1° pods fully developed and 2° and/or 3° pods formed = typical BPS symptoms

The University of Western Australia

Drawback: it takes 6 months (and a whole glasshouse) to get here!

The University of Western Australia

Lupin BPS samples positive for BYMV

BYMV inoculate to other host

BYMV used to infect healthy lupin

BPS symptoms occur

BYMV detected in formerly healthy lupin

Koch’s Postulates

The University of Western Australia

THE UWA INSTITUTE OF AGRICULTURE

Postgraduate Showcase 2013: Frontiers in Agriculture

BYMV causes BPS Time of infection critical for BPS symptoms Is the Nbm-1 gene responsible? Can closely related viruses cause BPS? Solution?

Summary