Identification and genomic mapping of

resistance to bacterial leaf streak

Zhaohui Liu

Department of Plant Pathology, NDSU

Jan. 13, 2017

have

Outline

• Introduction: The disease, the bacterium, management, host resistance

• Reaction of the ND malting barley cultivar and breeding lines to BLS

• Screening of mini-barley core collection and genetic mapping of resistance

• Some work on wheat/triticale BLS • Summary and future work

The disease

Bailey et al. 2003. Disease of field crops in Canada. 3rd Edition

• Bacterial blight • Bacterial leaf streak • Black chaff

Geographical distribution

Kurt Lindbeck 2011 http://www.planthealthaustralia.com.au/

Widespread distribution

Reports of pathogen detection Localized distribution

Impact on yield and quality

• Reduces test weight and/or the number of kernels per spike

• Usually 10% or less, but can reach 40%

• Follows a linear function of the percent infected flag leaf area

• Causes shriveled kernels and/or changed protein content Linear relationship of yield

and BLS severity on the flag leaf (Duveiller and Maraite 1993)

The pathogen

• Gram negative bacterium • Rod shape with a single polar

flagellum • Yellow mucoid colony • The name of the pathogen

Bacterium translucens

Phytomonas translucens

Xanthamonas campestris pv. translucens

Xanthomonas translucens

Xanthomonas translucens group (Bragard et al. 1997)

Pathovar Hosts

X. translucens pv. undulosa

(Xtu) wheat, triticale, barley

X. translucens pv. translucens

(Xtt) barley

X. translucens pv. cerealis

(Xtc)

wheat, rye, barley, oat, bromegrass

• Xanthomonas translucens “graminis group” cause bacterial wilt on forage and pasture grasses

Wheat

Barley

Wheat

Barley

Wheat strain Xtu

Barley strain Xtt

Pathogenicity of Xtu and Xtt

Life cycle

Spread in the field

Seeds, perennial weeds

Penetration and Multiplication

Progress of disease through plant

http://www.fao.org/docrep/006/y4011e/y4011e07.jpg

Overwintering

How to manage BLS • Use of pathogen-free seeds Clean and certified seeds Seed treatments: heat and dry, mercury-

based bactericides (banned), copper-based bactericides

• Weed control • No chemical is available for using in the field • Host resistance: the only option Partial resistance Less susceptible cultivars available

Host resistance • Some work has been done in wheat: no immune or

highly resistant materials, only partial resistance

• Very few has been done in barley Alizadeh et al. (1994) identified

three barley lines ‘Morex’, ‘Express’, ‘Iran-3a’ with partial resistance

The gene in Morex mapped to barley chromosome 3H (El Attari et al. 1997)

Barley cultivars and breeding lines screening

• In Fargo • Four replications with

RCBD • A ND barley strain used • Spray with a gas-powered

backpack sprayer • At the late tillering stage • A 0-9 disease scale

4.5

6 6.25

6.5 6.75 6.75

7 7

7.75

0123456789

10a

b

ab

Standard deviation is indicated as error bars Same letter indicates no significant difference

Dis

ease

seve

rity

Barley cultivars

0

1

2

3

4

5

6

7

8

9

10

The NDSU 2-row breeding lines • A total of 81 breeding lines from NDSU breeding program • A training population for genomic selection

Source DF Type I SS Mean Square F Value Pr > F

Reps 3 8.9969136 2.99897 1.45 0.228 Entry 80 456.05556 5.70069 2.76 <.0001

Screening of mini-barley core collection Country No. Country No. Country No.

United States 15 Peru 3 Turkey 2 Colombia 6 Poland 3 Turkistan 2 Netherlands 6 Russian Federation 3 Uzbekistan 2 South Africa 6 Sweden 3 Belarus 1 Canada 5 Tunisia 3 Brazil 1 China 5 Venezuela 3 Bulgaria 1 Ethiopia 5 Algeria 2 Croatia 1 Greece 5 Argentina 2 Cyprus 1 United Kingdom 5 Australia 2 Eritrea 1 Afghanistan 4 Austria 2 Former Soviet Union 1 Finland 4 Chile 2 India 1 France 4 Czech Republic 2 Italy 1 Georgia 4 Germany 2 Jordan 1 Iran 4 Iraq 2 Korea, North 1 Mongolia 4 Israel 2 Korea, South 1 Morocco 4 Mexico 2 Lebanon 1 Romania 4 New Zealand 2 Lithuania 1 Turkmenistan 4 Pakistan 2 Macedonia 1 Ukraine 4 Portugal 2 Montenegro 1 Czechoslovakia 3 Saudi Arabia 2 Norway 1 Denmark 3 Slovakia 2 Serbia 1 Egypt 3 Slovenia 2 Sudan 1 Hungary 3 Spain 2 Zimbabwe 1 Japan 3 Switzerland 2 Total 198

Nepal 3 Syria 2 country total 73

• A total of 198 lines selected from the world barley core collection (BCC)

• This mini-set captured the maximum diversity of the world BCC

• Natural infection and/or artificial inoculation

0

20

40

60

80

100

120

Two rowed

Six rowed

2013: natural 2014: natural and artificial 2015: natural 2016: artificial

0

20

40

60

80

100

120

0-3.0 3.1-6.0 7.1-9.0

2013_NAT

2014_NAT

2014_ART

2015_NAT

2016_NAT

Histogram of disease reaction for the mini-core set

Line No. Origin

Improvement

status Row type

Heading

datea

Disease

meanb Evaluation

BCN256 Sweden breeding line two 75 1.47 R BCN694 Eritrea Landrace two 64 2.18 R BCN825 Czechoslovakia cultivar two 67 2.27 R BCN192 Lithuania uncertain two 74 2.33 R BCN547 Netherlands cultivar two 71 2.40 R BCN706 South Africa breeding line two 70 2.40 R BCN 1849 Poland cultivar two 68 2.50 R BCN 1145 Saudi Arabia uncertain two 67 2.53 R BCN333 Netherlands cultivar two 70 2.58 R BCN 2040 United States breeding line two ND 2.63 R BCN988 United Kingdom cultivar two ND 2.93 R BCN711 South Africa breeding line two 70 4.28 R BCN 1540 Ethiopia Landrace six 67 1.60 R BCN60 Bulgaria uncertain six 95 1.80 R BCN 1875 Peru Landrace six 69 1.80 R BCN 1548 Romania uncertain six 111 2.45 R BCN179 China Landrace six 67 2.58 R BCN 1660 Finland cultivar six 68 2.70 R BCN441 Hungary uncertain six 60 3.00 R BCN708 South Africa breeding line two 69 8.20 S BCN571 Argentina cultivar two 69 8.23 S BCN981 Australia cultivar two ND 8.58 S BCN1447 Afghanistan Landrace six 77 8.20 S BCN1555 Australia uncertain six 70 8.45 S

aData was taken from the USDA-National Plant Germplasm System website (//npgsweb.ars-grin.gov) bDisease means are the average of five experiments from 2013 to 2016.

List of barley lines that were resistant to BLS in the disease evaluation across multiple years

BCN694 BCN571

BCN1074 BCN902

Examples of resistant and susceptible barley lines in the field (2015)

Association mapping in barley mini-core

2013_NAT

1H 2H 3H 4H 5H 6H 7H

With all markers

With heading date markers as covariate

Association mapping in barley mini-core

2016_ART

1H 2H 3H 4H 5H 6H 7H

With all markers

With heading date markers as covariate

Conlon PI392491 (BCN706)

Segregation of Conlon × PI392491 population 0

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3

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5

6

7

8

9

10

QTL mapping in the RIL population derived from Conlon × PI392491

QTL mapping in the doubled haploid population derived from Q21816 ×SM89010

Q21861

SM89010

Some BLS work on wheat and triticale • Screening diverse wheat germplasm for resistance

in the field and greenhouse • Association mapping using different wheat

germplasm panels • QTL mapping of resistance in bi-parental

populations

Establish a greenhouse protocol on disease evaluation

Culture Harvesting Inoculum

spray Misting

Disease rating

L12G09

L12G08

L12G18

RB07

Reaction of triticale accessions and wheat to BLS in greenhouse

0

5

10

15

20

25

A single major QTL was identified for resistance to BLS on the chromosome 5R in L12G09 (R) × L12G18 (S) population.

LB10 (ND strain) LOD=22, R2=54%

Xt4699 (KS strain) LOD=20, R2=50%

Summary and future work

• A protocol for field disease screening has been establish in Fargo, ND, but needs to be optimized.

• Genetic variation exists among barley cultivars, breeding lines and accessions we tested and a few barley accessions from mini-core was shown to be highly resistant across multiple years.

• Preliminary results from association and QTL mapping showed barley chromosomes 1H, 3H, 6H, and 7H could harboring resistance gene/QTL. These QTL are environmentally dependent.

• Bi-parental barley populations are being developed for mapping resistance genes.

Acknowledgements My program Dr. Gongjun Shi Dr. Aimin Wen Mrs. Jana Hansen Ms. Malini Jayawardana

NDSU Dr. Robert Brueggeman

-Dr. Jon Richard -Mr. Roshan Poudel -Mr. Patrick Gross

Dr. Richard Horsley -Mr. Martin Hochhalter

MSU Dr. Jamie Sherman UMN Dr. Ruth Dill-Mackey SDSU Dr. Shaukat Ali KSU Dr. Frank White Dr. Sanzhen Liu