Quantitative PCR and histopathological assessment of

cereal infection by Fusarium pseudograminearum.

Supervisors: Prof. Mark Sutherland, Dr. Anke Martin and Dr. Damian Herde

Noel Knight

Crown Rot• Crown rot (F. pseudograminearum)

~ $100 million per annum

Aims

25um

• Examine cereal tissues affected by Fp crown rot using visual and qPCR rating methods

• Microscopically observe Fp growth through cereal tissues

• Resistance assessed visually– Brown discolouration of internodes

• qPCR assay amplifies Fp Translation Elongation Factor α DNA

Determining Host Resistance

Internodes

Crown Rot of Adult Plants

Genotype Species Crown Rot Resistance2-49 T.aestivum Partially Resistant

Grimmett H. vulgare Moderately SusceptiblePuseas T.aestivum SusceptibleBellaroi T.turgidum durum Very Susceptible

• 16 and 22 weeks after planting (WAP)

Crown Rot of Adult Plants16 WAPAnthesis

2-49

Grimmett

Puseas

BellaroiFp

DN

A (n

g) /

gFp

DN

A (n

g) /

g

Pearson’s r0.86

0.5822 WAPMaturity

Stem Tissue Types

Parenchymatous hypoderm

50µm 50µmEpidermis

Sclerenchymatous hypoderm

Pith parenchyma

Large vascular bundle

Small vascular bundle

Vascular parenchyma

Adult Tissue Microscopy

25µm50µm

25µm25µm

Knight and Sutherland (2011) Plant Pathology

Safranin

Solophenyl flavine

Adult Tissue Microscopy

25µm

25µm

25µm50µm

Adult Tissue Microscopy

400µm 400µm

h

pc h

25µm

st

50µm 25µm50µm

• Strong correlation between IN discolouration and Fp DNA at 16 WAP

• Significant differences in Fp DNA quantity between R and S cereals at 16 WAP

• Fp colonises all cell types– vascular tissues colonised

Summary

Questions?