IntroductionResults and Discussion

Summary

Origins of New Zealand’s Rhizobia

Bevan Weir

Landcare Research

Centre for Biodiversity and Biosecurity Seminar16 May 2006

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Outline

1 IntroductionRhizobia and legumesThe Question: Origin of the rhizobia

2 Results and DiscussionPhylogenetic analysesNodulation gene analysisHost-range testing

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Outline

1 IntroductionRhizobia and legumesThe Question: Origin of the rhizobia

2 Results and DiscussionPhylogenetic analysesNodulation gene analysisHost-range testing

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

What are rhizobia?

Figure: Acacia root nodule

BacteriaSpecific symbiosis withlegumesForm N2-fixing rootnodules

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Native legumes

Figure: Sophora chathamica Figure: Clianthus puniceus

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Native legumes

Figure: Carmichaelia australis

Figure: Montigenanovae-zelandiae c© Peter Heenan

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Introduced legumes

Figure: Ulex europaeus (Gorse) Figure: Cytisus scoparius(Broom) CC© Jon J. Sullivan

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Introduced legumes

Figure: Acacia longifolia CC© Brenda Foran

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Outline

1 IntroductionRhizobia and legumesThe Question: Origin of the rhizobia

2 Results and DiscussionPhylogenetic analysesNodulation gene analysisHost-range testing

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Legume arrival in NZ

Dates inferred by fossil pollen and phylogenetic trees.

Native legumes arrived ≈ 5 million years agoPresumably have co-evolved with native rhizobia.

Exotic legumes arrived < 200 years agoWith what rhizobia have they nodulated?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Legume arrival in NZ

Dates inferred by fossil pollen and phylogenetic trees.

Native legumes arrived ≈ 5 million years agoPresumably have co-evolved with native rhizobia.

Exotic legumes arrived < 200 years agoWith what rhizobia have they nodulated?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Legume arrival in NZ

Dates inferred by fossil pollen and phylogenetic trees.

Native legumes arrived ≈ 5 million years agoPresumably have co-evolved with native rhizobia.

Exotic legumes arrived < 200 years agoWith what rhizobia have they nodulated?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Legume arrival in NZ

Dates inferred by fossil pollen and phylogenetic trees.

Native legumes arrived ≈ 5 million years agoPresumably have co-evolved with native rhizobia.

Exotic legumes arrived < 200 years agoWith what rhizobia have they nodulated?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Nodulation of introduced legumes

Possibilities for nodulation of introduced legumes1 Nodulated by same rhizobia as native legumes.2 Nodulated by introduced specific rhizobia.3 Nodulated by cosmopolitan specific rhizobia.

What species are nodulating native and exotic legumes in NewZealand?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Nodulation of introduced legumes

Possibilities for nodulation of introduced legumes1 Nodulated by same rhizobia as native legumes.2 Nodulated by introduced specific rhizobia.3 Nodulated by cosmopolitan specific rhizobia.

What species are nodulating native and exotic legumes in NewZealand?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Nodulation of introduced legumes

Possibilities for nodulation of introduced legumes1 Nodulated by same rhizobia as native legumes.2 Nodulated by introduced specific rhizobia.3 Nodulated by cosmopolitan specific rhizobia.

What species are nodulating native and exotic legumes in NewZealand?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Rhizobia and legumesThe Question: Origin of the rhizobia

Nodulation of introduced legumes

Possibilities for nodulation of introduced legumes1 Nodulated by same rhizobia as native legumes.2 Nodulated by introduced specific rhizobia.3 Nodulated by cosmopolitan specific rhizobia.

What species are nodulating native and exotic legumes in NewZealand?

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Outline

1 IntroductionRhizobia and legumesThe Question: Origin of the rhizobia

2 Results and DiscussionPhylogenetic analysesNodulation gene analysisHost-range testing

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Methods

Isolated 40 strains from root nodules.Sequenced 4 genes: 16S, recA, atpD, glnII.Built phylogenetic trees using NJ, ML, Bayesian, ProtTest.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Determined the identity of rhizobia

0.1

11541 ( )Carmichaelia13190 ( )Carmichaelia11722 ( )Carmichaelia12635 ( )Carmichaelia14319 ( )Carmichaelia12680 ( )Clianthus

11708 ( )Carmichaelia12690 ( )Montigena

M huakuiiesorhizobiumM plurifariumesorhizobium

11721 ( )Clianthus

Mesorhizobium septentrionale

11720 ( )Clianthus11726 ( )ClianthusMesorhizobium amorphae

M chacoenseesorhizobiumM tianshanenseesorhizobium

M mediterraneumesorhizobiumMesorhizobium temperatum

11736 ( )Sophora12637 ( )Sophora11719 ( )Sophora15054 ( )Carmichaelia14330 ( )Sophora12649 ( )Carmichaelia

M ciceriesorhizobium12685 ( )Montigena

M lotiesorhizobiumRhizobium leguminosarum

Rhizobium etli14642117271154212687

Rhizobium tropiciEnsifer frediiEnsifer saheli

Ensifer meliloti12835 ( )Acacia14754 ( )Acacia

14533 ( )Ulex14755 ( )Acacia

14753 ( )Albizia14304 ( )Ulex

12674 ( )Cytisus

Bradyrhizobium canariense14320 ( )Ulex

14306 ( )Ulex14310 ( )Cytisus14309 ( )Cytisus14328 ( )Cytisus14292 ( )Ulex14291 ( )Cytisus12624 ( )Cytisus14752 ( )Albizia

Bradyrhizobium liaoningenseBradyrhizobium yuanmingense

Bradyrhizobium japonicumBradyrhizobium elkanii

Group H

Group D

Group A

Group C

Group B

Group E

Group F

Group G

16SML

High diversity.No relationship betweenrhizobial group and host.Native legumes→Mesorhizobium.Introduced legumes→Bradyrhizobium.Native and introducedlegumes do not share rhizobia.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Nodulation of introduced legumes

Possibilities for nodulation of introduced legumes1 Nodulated by same rhizobia as native legumes.2 Nodulated by introduced specific rhizobia.3 Nodulated by cosmopolitan specific rhizobia.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Bradyrhizobium cosmopolitan or introduced?

High diversity may indicate cosmopolitan bacteria with along presence in NZ.But: The Mesorhizobium–Bradyrhizobium split was 500mya, well before the evolution of legume symbiosis (< 80mya).In the next experiments I looked at symbiosis genes andnodulation ability.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Bradyrhizobium cosmopolitan or introduced?

High diversity may indicate cosmopolitan bacteria with along presence in NZ.But: The Mesorhizobium–Bradyrhizobium split was 500mya, well before the evolution of legume symbiosis (< 80mya).In the next experiments I looked at symbiosis genes andnodulation ability.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Bradyrhizobium cosmopolitan or introduced?

High diversity may indicate cosmopolitan bacteria with along presence in NZ.But: The Mesorhizobium–Bradyrhizobium split was 500mya, well before the evolution of legume symbiosis (< 80mya).In the next experiments I looked at symbiosis genes andnodulation ability.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Bradyrhizobium cosmopolitan or introduced?

High diversity may indicate cosmopolitan bacteria with along presence in NZ.But: The Mesorhizobium–Bradyrhizobium split was 500mya, well before the evolution of legume symbiosis (< 80mya).In the next experiments I looked at symbiosis genes andnodulation ability.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Outline

1 IntroductionRhizobia and legumesThe Question: Origin of the rhizobia

2 Results and DiscussionPhylogenetic analysesNodulation gene analysisHost-range testing

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Nod factor

Figure: Nod factor(lipo-chito-oligosaccharide)

nod genes form the nodfactor.Critical molecule innodule formation.Found on transmissiblegenetic elements.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Nod factor

Figure: Nod factor(lipo-chito-oligosaccharide)

nod genes form the nodfactor.Critical molecule innodule formation.Found on transmissiblegenetic elements.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

nodA gene

0.1

0.83

0.65

0.56

1.00

0.85

0.96

1.00

1.00

0.98

0.72

0.56

1.001.00

0.98

0.99

1.00

0.54

1.00

0.851.00

0.97

1.00

1.00

0.51

1.00

1.00

1.00

0.93

0.57

1.00

0.56

0.731.00

0.87

0.75

1.00

Bradyrhizobium sp. USDA3001

Bradyrhizobium Albiziasp. 14752 ( )

Bradyrhizobium Acaciasp. 14754 ( )

Bradyrhizobium sp. USDA3475Bradyrhizobium Albiziasp. 14753 ( )

Bradyrhizobium sp. BDV5325

Bradyrhizobium Acaciasp. 12835 ( )

Bradyrhizobium Acaciasp. 14755 ( )

Bradyrhizobium sp. Genista10Bradyrhizobium Ulexsp. 14306 ( )

Bradyrhizobium Cytisussp. 14291 ( )Bradyrhizobium Ulexsp. 14533 ( )

Bradyrhizobium sp. ARC403

Bradyrhizobium Cytisussp. 12624 ( )

Bradyrhizobium Cytisussp. 12674 ( )

Bradyrhizobium sp. Osaka6

Bradyrhizobium japonicum

Methylobacterium nodulansBurkholderia tuberum

Mesorhizobium plurifarium 13640

Mesorhizobium plurifarium ORS1001

Mesorhizobium sp. DWO366

Rhizobium sp. TAL1145

Rhizobium gallicum

Ensifer terangae

Mesorhizobium septentrionale

Mesorhizobium Sophorasp. 11719 ( ) A

Mesorhizobium Sophorasp. 14330 ( ) A

Mesorhizobium Sophorasp. 11736 ( ) A

R. leguminosarum 2672

R. etli CFN42

R. leg Clianthus11542 ( ) E

R. leguminosarum trifoliibv.

R. leg Carmichaelia12687 ( ) E

R. leg Carmichaelia11727 ( ) E

NLNP4 isolate

R. leguminosarum trifoliibv. ANU

R. leguminosarum 5943

R. leguminosarum pRL1JI

R. leg Sophora14642 ( ) E

R. mongolense USDA1844

Mesorhizobium loti R7AMesorhizobium loti MAFF303099

Mesorhizobium Montigenasp. 12690 ( ) D

Mesorhizobium Clianthussp. 11541 ( ) D

Mesorhizobium Carmichaeliasp. 14319 ( ) D

Mesorhizobium temperatum

Mesorhizobium tianshanense

Mesorhizobium ciceri

Mesorhizobium mediterraneum

Mesorhizobium Carmichaeliasp. 12649 ( ) A

Mesorhizobium Clianthussp. 12680 ( ) D

Mesorhizobium Carmichaeliasp. 11708 ( ) D

Mesorhizobium Montigenasp. 12685 ( ) B

Mesorhizobium Carmichaeliasp. 13190 ( ) D

Mesorhizobium Clianthussp. 11721 ( ) C

Mesorhizobium Clianthussp. 11726 ( ) C

Mesorhizobium Clianthussp. 11720 ( ) C

Mesorhizobium Carmichaeliasp. 15054 ( ) A

Mesorhizobium Carmichaeliasp. 11722 ( ) D

Azorhizobium sp. SD02

Type 3‘Sophora’

Type 1‘Carmichaelinae 1’

Type 2‘Carmichaelinae 2’

Type 7‘Genisteae’

Type 4‘Trifolii’

Type 8‘Acacia’

Type 5‘Viciae’

Type 6‘Phaseoli’

Mesorhizobium sp. WSM2074

NodA proteinBayesian

Little correlation withhouse keeping genes.

Host specificity.Horizontal genetransfer.

Novel nodA genes innatives.

Genetic drift (wobblebase).Selection (duringdiversification).

nodA genes ofintroduced are similar tooverseas sequences.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

nodA gene

0.1

0.83

0.65

0.56

1.00

0.85

0.96

1.00

1.00

0.98

0.72

0.56

1.001.00

0.98

0.99

1.00

0.54

1.00

0.851.00

0.97

1.00

1.00

0.51

1.00

1.00

1.00

0.93

0.57

1.00

0.56

0.731.00

0.87

0.75

1.00

Bradyrhizobium sp. USDA3001

Bradyrhizobium Albiziasp. 14752 ( )

Bradyrhizobium Acaciasp. 14754 ( )

Bradyrhizobium sp. USDA3475Bradyrhizobium Albiziasp. 14753 ( )

Bradyrhizobium sp. BDV5325

Bradyrhizobium Acaciasp. 12835 ( )

Bradyrhizobium Acaciasp. 14755 ( )

Bradyrhizobium sp. Genista10Bradyrhizobium Ulexsp. 14306 ( )

Bradyrhizobium Cytisussp. 14291 ( )Bradyrhizobium Ulexsp. 14533 ( )

Bradyrhizobium sp. ARC403

Bradyrhizobium Cytisussp. 12624 ( )

Bradyrhizobium Cytisussp. 12674 ( )

Bradyrhizobium sp. Osaka6

Bradyrhizobium japonicum

Methylobacterium nodulansBurkholderia tuberum

Mesorhizobium plurifarium 13640

Mesorhizobium plurifarium ORS1001

Mesorhizobium sp. DWO366

Rhizobium sp. TAL1145

Rhizobium gallicum

Ensifer terangae

Mesorhizobium septentrionale

Mesorhizobium Sophorasp. 11719 ( ) A

Mesorhizobium Sophorasp. 14330 ( ) A

Mesorhizobium Sophorasp. 11736 ( ) A

R. leguminosarum 2672

R. etli CFN42

R. leg Clianthus11542 ( ) E

R. leguminosarum trifoliibv.

R. leg Carmichaelia12687 ( ) E

R. leg Carmichaelia11727 ( ) E

NLNP4 isolate

R. leguminosarum trifoliibv. ANU

R. leguminosarum 5943

R. leguminosarum pRL1JI

R. leg Sophora14642 ( ) E

R. mongolense USDA1844

Mesorhizobium loti R7AMesorhizobium loti MAFF303099

Mesorhizobium Montigenasp. 12690 ( ) D

Mesorhizobium Clianthussp. 11541 ( ) D

Mesorhizobium Carmichaeliasp. 14319 ( ) D

Mesorhizobium temperatum

Mesorhizobium tianshanense

Mesorhizobium ciceri

Mesorhizobium mediterraneum

Mesorhizobium Carmichaeliasp. 12649 ( ) A

Mesorhizobium Clianthussp. 12680 ( ) D

Mesorhizobium Carmichaeliasp. 11708 ( ) D

Mesorhizobium Montigenasp. 12685 ( ) B

Mesorhizobium Carmichaeliasp. 13190 ( ) D

Mesorhizobium Clianthussp. 11721 ( ) C

Mesorhizobium Clianthussp. 11726 ( ) C

Mesorhizobium Clianthussp. 11720 ( ) C

Mesorhizobium Carmichaeliasp. 15054 ( ) A

Mesorhizobium Carmichaeliasp. 11722 ( ) D

Azorhizobium sp. SD02

Type 3‘Sophora’

Type 1‘Carmichaelinae 1’

Type 2‘Carmichaelinae 2’

Type 7‘Genisteae’

Type 4‘Trifolii’

Type 8‘Acacia’

Type 5‘Viciae’

Type 6‘Phaseoli’

Mesorhizobium sp. WSM2074

NodA proteinBayesian

Little correlation withhouse keeping genes.

Host specificity.Horizontal genetransfer.

Novel nodA genes innatives.

Genetic drift (wobblebase).Selection (duringdiversification).

nodA genes ofintroduced are similar tooverseas sequences.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

nodA gene

0.1

0.83

0.65

0.56

1.00

0.85

0.96

1.00

1.00

0.98

0.72

0.56

1.001.00

0.98

0.99

1.00

0.54

1.00

0.851.00

0.97

1.00

1.00

0.51

1.00

1.00

1.00

0.93

0.57

1.00

0.56

0.731.00

0.87

0.75

1.00

Bradyrhizobium sp. USDA3001

Bradyrhizobium Albiziasp. 14752 ( )

Bradyrhizobium Acaciasp. 14754 ( )

Bradyrhizobium sp. USDA3475Bradyrhizobium Albiziasp. 14753 ( )

Bradyrhizobium sp. BDV5325

Bradyrhizobium Acaciasp. 12835 ( )

Bradyrhizobium Acaciasp. 14755 ( )

Bradyrhizobium sp. Genista10Bradyrhizobium Ulexsp. 14306 ( )

Bradyrhizobium Cytisussp. 14291 ( )Bradyrhizobium Ulexsp. 14533 ( )

Bradyrhizobium sp. ARC403

Bradyrhizobium Cytisussp. 12624 ( )

Bradyrhizobium Cytisussp. 12674 ( )

Bradyrhizobium sp. Osaka6

Bradyrhizobium japonicum

Methylobacterium nodulansBurkholderia tuberum

Mesorhizobium plurifarium 13640

Mesorhizobium plurifarium ORS1001

Mesorhizobium sp. DWO366

Rhizobium sp. TAL1145

Rhizobium gallicum

Ensifer terangae

Mesorhizobium septentrionale

Mesorhizobium Sophorasp. 11719 ( ) A

Mesorhizobium Sophorasp. 14330 ( ) A

Mesorhizobium Sophorasp. 11736 ( ) A

R. leguminosarum 2672

R. etli CFN42

R. leg Clianthus11542 ( ) E

R. leguminosarum trifoliibv.

R. leg Carmichaelia12687 ( ) E

R. leg Carmichaelia11727 ( ) E

NLNP4 isolate

R. leguminosarum trifoliibv. ANU

R. leguminosarum 5943

R. leguminosarum pRL1JI

R. leg Sophora14642 ( ) E

R. mongolense USDA1844

Mesorhizobium loti R7AMesorhizobium loti MAFF303099

Mesorhizobium Montigenasp. 12690 ( ) D

Mesorhizobium Clianthussp. 11541 ( ) D

Mesorhizobium Carmichaeliasp. 14319 ( ) D

Mesorhizobium temperatum

Mesorhizobium tianshanense

Mesorhizobium ciceri

Mesorhizobium mediterraneum

Mesorhizobium Carmichaeliasp. 12649 ( ) A

Mesorhizobium Clianthussp. 12680 ( ) D

Mesorhizobium Carmichaeliasp. 11708 ( ) D

Mesorhizobium Montigenasp. 12685 ( ) B

Mesorhizobium Carmichaeliasp. 13190 ( ) D

Mesorhizobium Clianthussp. 11721 ( ) C

Mesorhizobium Clianthussp. 11726 ( ) C

Mesorhizobium Clianthussp. 11720 ( ) C

Mesorhizobium Carmichaeliasp. 15054 ( ) A

Mesorhizobium Carmichaeliasp. 11722 ( ) D

Azorhizobium sp. SD02

Type 3‘Sophora’

Type 1‘Carmichaelinae 1’

Type 2‘Carmichaelinae 2’

Type 7‘Genisteae’

Type 4‘Trifolii’

Type 8‘Acacia’

Type 5‘Viciae’

Type 6‘Phaseoli’

Mesorhizobium sp. WSM2074

NodA proteinBayesian

Little correlation withhouse keeping genes.

Host specificity.Horizontal genetransfer.

Novel nodA genes innatives.

Genetic drift (wobblebase).Selection (duringdiversification).

nodA genes ofintroduced are similar tooverseas sequences.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

nodA gene

0.1

0.83

0.65

0.56

1.00

0.85

0.96

1.00

1.00

0.98

0.72

0.56

1.001.00

0.98

0.99

1.00

0.54

1.00

0.851.00

0.97

1.00

1.00

0.51

1.00

1.00

1.00

0.93

0.57

1.00

0.56

0.731.00

0.87

0.75

1.00

Bradyrhizobium sp. USDA3001

Bradyrhizobium Albiziasp. 14752 ( )

Bradyrhizobium Acaciasp. 14754 ( )

Bradyrhizobium sp. USDA3475Bradyrhizobium Albiziasp. 14753 ( )

Bradyrhizobium sp. BDV5325

Bradyrhizobium Acaciasp. 12835 ( )

Bradyrhizobium Acaciasp. 14755 ( )

Bradyrhizobium sp. Genista10Bradyrhizobium Ulexsp. 14306 ( )

Bradyrhizobium Cytisussp. 14291 ( )Bradyrhizobium Ulexsp. 14533 ( )

Bradyrhizobium sp. ARC403

Bradyrhizobium Cytisussp. 12624 ( )

Bradyrhizobium Cytisussp. 12674 ( )

Bradyrhizobium sp. Osaka6

Bradyrhizobium japonicum

Methylobacterium nodulansBurkholderia tuberum

Mesorhizobium plurifarium 13640

Mesorhizobium plurifarium ORS1001

Mesorhizobium sp. DWO366

Rhizobium sp. TAL1145

Rhizobium gallicum

Ensifer terangae

Mesorhizobium septentrionale

Mesorhizobium Sophorasp. 11719 ( ) A

Mesorhizobium Sophorasp. 14330 ( ) A

Mesorhizobium Sophorasp. 11736 ( ) A

R. leguminosarum 2672

R. etli CFN42

R. leg Clianthus11542 ( ) E

R. leguminosarum trifoliibv.

R. leg Carmichaelia12687 ( ) E

R. leg Carmichaelia11727 ( ) E

NLNP4 isolate

R. leguminosarum trifoliibv. ANU

R. leguminosarum 5943

R. leguminosarum pRL1JI

R. leg Sophora14642 ( ) E

R. mongolense USDA1844

Mesorhizobium loti R7AMesorhizobium loti MAFF303099

Mesorhizobium Montigenasp. 12690 ( ) D

Mesorhizobium Clianthussp. 11541 ( ) D

Mesorhizobium Carmichaeliasp. 14319 ( ) D

Mesorhizobium temperatum

Mesorhizobium tianshanense

Mesorhizobium ciceri

Mesorhizobium mediterraneum

Mesorhizobium Carmichaeliasp. 12649 ( ) A

Mesorhizobium Clianthussp. 12680 ( ) D

Mesorhizobium Carmichaeliasp. 11708 ( ) D

Mesorhizobium Montigenasp. 12685 ( ) B

Mesorhizobium Carmichaeliasp. 13190 ( ) D

Mesorhizobium Clianthussp. 11721 ( ) C

Mesorhizobium Clianthussp. 11726 ( ) C

Mesorhizobium Clianthussp. 11720 ( ) C

Mesorhizobium Carmichaeliasp. 15054 ( ) A

Mesorhizobium Carmichaeliasp. 11722 ( ) D

Azorhizobium sp. SD02

Type 3‘Sophora’

Type 1‘Carmichaelinae 1’

Type 2‘Carmichaelinae 2’

Type 7‘Genisteae’

Type 4‘Trifolii’

Type 8‘Acacia’

Type 5‘Viciae’

Type 6‘Phaseoli’

Mesorhizobium sp. WSM2074

NodA proteinBayesian

Little correlation withhouse keeping genes.

Host specificity.Horizontal genetransfer.

Novel nodA genes innatives.

Genetic drift (wobblebase).Selection (duringdiversification).

nodA genes ofintroduced are similar tooverseas sequences.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

nodA gene

0.1

0.83

0.65

0.56

1.00

0.85

0.96

1.00

1.00

0.98

0.72

0.56

1.001.00

0.98

0.99

1.00

0.54

1.00

0.851.00

0.97

1.00

1.00

0.51

1.00

1.00

1.00

0.93

0.57

1.00

0.56

0.731.00

0.87

0.75

1.00

Bradyrhizobium sp. USDA3001

Bradyrhizobium Albiziasp. 14752 ( )

Bradyrhizobium Acaciasp. 14754 ( )

Bradyrhizobium sp. USDA3475Bradyrhizobium Albiziasp. 14753 ( )

Bradyrhizobium sp. BDV5325

Bradyrhizobium Acaciasp. 12835 ( )

Bradyrhizobium Acaciasp. 14755 ( )

Bradyrhizobium sp. Genista10Bradyrhizobium Ulexsp. 14306 ( )

Bradyrhizobium Cytisussp. 14291 ( )Bradyrhizobium Ulexsp. 14533 ( )

Bradyrhizobium sp. ARC403

Bradyrhizobium Cytisussp. 12624 ( )

Bradyrhizobium Cytisussp. 12674 ( )

Bradyrhizobium sp. Osaka6

Bradyrhizobium japonicum

Methylobacterium nodulansBurkholderia tuberum

Mesorhizobium plurifarium 13640

Mesorhizobium plurifarium ORS1001

Mesorhizobium sp. DWO366

Rhizobium sp. TAL1145

Rhizobium gallicum

Ensifer terangae

Mesorhizobium septentrionale

Mesorhizobium Sophorasp. 11719 ( ) A

Mesorhizobium Sophorasp. 14330 ( ) A

Mesorhizobium Sophorasp. 11736 ( ) A

R. leguminosarum 2672

R. etli CFN42

R. leg Clianthus11542 ( ) E

R. leguminosarum trifoliibv.

R. leg Carmichaelia12687 ( ) E

R. leg Carmichaelia11727 ( ) E

NLNP4 isolate

R. leguminosarum trifoliibv. ANU

R. leguminosarum 5943

R. leguminosarum pRL1JI

R. leg Sophora14642 ( ) E

R. mongolense USDA1844

Mesorhizobium loti R7AMesorhizobium loti MAFF303099

Mesorhizobium Montigenasp. 12690 ( ) D

Mesorhizobium Clianthussp. 11541 ( ) D

Mesorhizobium Carmichaeliasp. 14319 ( ) D

Mesorhizobium temperatum

Mesorhizobium tianshanense

Mesorhizobium ciceri

Mesorhizobium mediterraneum

Mesorhizobium Carmichaeliasp. 12649 ( ) A

Mesorhizobium Clianthussp. 12680 ( ) D

Mesorhizobium Carmichaeliasp. 11708 ( ) D

Mesorhizobium Montigenasp. 12685 ( ) B

Mesorhizobium Carmichaeliasp. 13190 ( ) D

Mesorhizobium Clianthussp. 11721 ( ) C

Mesorhizobium Clianthussp. 11726 ( ) C

Mesorhizobium Clianthussp. 11720 ( ) C

Mesorhizobium Carmichaeliasp. 15054 ( ) A

Mesorhizobium Carmichaeliasp. 11722 ( ) D

Azorhizobium sp. SD02

Type 3‘Sophora’

Type 1‘Carmichaelinae 1’

Type 2‘Carmichaelinae 2’

Type 7‘Genisteae’

Type 4‘Trifolii’

Type 8‘Acacia’

Type 5‘Viciae’

Type 6‘Phaseoli’

Mesorhizobium sp. WSM2074

NodA proteinBayesian

Little correlation withhouse keeping genes.

Host specificity.Horizontal genetransfer.

Novel nodA genes innatives.

Genetic drift (wobblebase).Selection (duringdiversification).

nodA genes ofintroduced are similar tooverseas sequences.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

nodA gene

0.1

0.83

0.65

0.56

1.00

0.85

0.96

1.00

1.00

0.98

0.72

0.56

1.001.00

0.98

0.99

1.00

0.54

1.00

0.851.00

0.97

1.00

1.00

0.51

1.00

1.00

1.00

0.93

0.57

1.00

0.56

0.731.00

0.87

0.75

1.00

Bradyrhizobium sp. USDA3001

Bradyrhizobium Albiziasp. 14752 ( )

Bradyrhizobium Acaciasp. 14754 ( )

Bradyrhizobium sp. USDA3475Bradyrhizobium Albiziasp. 14753 ( )

Bradyrhizobium sp. BDV5325

Bradyrhizobium Acaciasp. 12835 ( )

Bradyrhizobium Acaciasp. 14755 ( )

Bradyrhizobium sp. Genista10Bradyrhizobium Ulexsp. 14306 ( )

Bradyrhizobium Cytisussp. 14291 ( )Bradyrhizobium Ulexsp. 14533 ( )

Bradyrhizobium sp. ARC403

Bradyrhizobium Cytisussp. 12624 ( )

Bradyrhizobium Cytisussp. 12674 ( )

Bradyrhizobium sp. Osaka6

Bradyrhizobium japonicum

Methylobacterium nodulansBurkholderia tuberum

Mesorhizobium plurifarium 13640

Mesorhizobium plurifarium ORS1001

Mesorhizobium sp. DWO366

Rhizobium sp. TAL1145

Rhizobium gallicum

Ensifer terangae

Mesorhizobium septentrionale

Mesorhizobium Sophorasp. 11719 ( ) A

Mesorhizobium Sophorasp. 14330 ( ) A

Mesorhizobium Sophorasp. 11736 ( ) A

R. leguminosarum 2672

R. etli CFN42

R. leg Clianthus11542 ( ) E

R. leguminosarum trifoliibv.

R. leg Carmichaelia12687 ( ) E

R. leg Carmichaelia11727 ( ) E

NLNP4 isolate

R. leguminosarum trifoliibv. ANU

R. leguminosarum 5943

R. leguminosarum pRL1JI

R. leg Sophora14642 ( ) E

R. mongolense USDA1844

Mesorhizobium loti R7AMesorhizobium loti MAFF303099

Mesorhizobium Montigenasp. 12690 ( ) D

Mesorhizobium Clianthussp. 11541 ( ) D

Mesorhizobium Carmichaeliasp. 14319 ( ) D

Mesorhizobium temperatum

Mesorhizobium tianshanense

Mesorhizobium ciceri

Mesorhizobium mediterraneum

Mesorhizobium Carmichaeliasp. 12649 ( ) A

Mesorhizobium Clianthussp. 12680 ( ) D

Mesorhizobium Carmichaeliasp. 11708 ( ) D

Mesorhizobium Montigenasp. 12685 ( ) B

Mesorhizobium Carmichaeliasp. 13190 ( ) D

Mesorhizobium Clianthussp. 11721 ( ) C

Mesorhizobium Clianthussp. 11726 ( ) C

Mesorhizobium Clianthussp. 11720 ( ) C

Mesorhizobium Carmichaeliasp. 15054 ( ) A

Mesorhizobium Carmichaeliasp. 11722 ( ) D

Azorhizobium sp. SD02

Type 3‘Sophora’

Type 1‘Carmichaelinae 1’

Type 2‘Carmichaelinae 2’

Type 7‘Genisteae’

Type 4‘Trifolii’

Type 8‘Acacia’

Type 5‘Viciae’

Type 6‘Phaseoli’

Mesorhizobium sp. WSM2074

NodA proteinBayesian

Little correlation withhouse keeping genes.

Host specificity.Horizontal genetransfer.

Novel nodA genes innatives.

Genetic drift (wobblebase).Selection (duringdiversification).

nodA genes ofintroduced are similar tooverseas sequences.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Nodulation of introduced legumes

Possibilities for nodulation of introduced legumes1 Nodulated by same rhizobia as native legumes.2 Nodulated by introduced specific rhizobia.3 Nodulated by cosmopolitan specific rhizobia.

Rhizobia cells might be cosmopolitan, but transmissiblesymbiosis regions are not.May have transferred to other rhizobia upon arrival.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Nodulation of introduced legumes

Possibilities for nodulation of introduced legumes1 Nodulated by same rhizobia as native legumes.2 Nodulated by introduced specific rhizobia.3 Nodulated by cosmopolitan specific rhizobia.

Rhizobia cells might be cosmopolitan, but transmissiblesymbiosis regions are not.May have transferred to other rhizobia upon arrival.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Outline

1 IntroductionRhizobia and legumesThe Question: Origin of the rhizobia

2 Results and DiscussionPhylogenetic analysesNodulation gene analysisHost-range testing

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Host-range experiments

Figure: Sophora growing invermiculite

Tested the ability ofMesorhizobium andBradyrhizobium spp. tonodulate native andintroduced species.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Methods

Figure: Ineffective and EffectiveClianthus nodules

Standard suspension ofrhizobia.Sterile vermiculite, andseeds.10 weeks growth.Nitrogenase assay, thenuprooted and examinednodules.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Rhizobia isolated from native legumes (Mesorhizobiumspp.) could generally effectively nodulate other nativelegumes (nod+ fix+).

Some strain variationNo clear link to nodA or genotype

Rhizobia isolated from introduced legumes(Bradyrhizobium spp.) could generally effectively nodulateother introduced legumes (nod+ fix+).

Rhizobia from gorse/broom was ineffective on Acacia (nod+

fix−).

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Rhizobia isolated from native legumes (Mesorhizobiumspp.) could generally effectively nodulate other nativelegumes (nod+ fix+).

Some strain variationNo clear link to nodA or genotype

Rhizobia isolated from introduced legumes(Bradyrhizobium spp.) could generally effectively nodulateother introduced legumes (nod+ fix+).

Rhizobia from gorse/broom was ineffective on Acacia (nod+

fix−).

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Rhizobia isolated from native legumes (Mesorhizobiumspp.) could generally effectively nodulate other nativelegumes (nod+ fix+).

Some strain variationNo clear link to nodA or genotype

Rhizobia isolated from introduced legumes(Bradyrhizobium spp.) could generally effectively nodulateother introduced legumes (nod+ fix+).

Rhizobia from gorse/broom was ineffective on Acacia (nod+

fix−).

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Rhizobia isolated from native legumes (Mesorhizobiumspp.) could generally effectively nodulate other nativelegumes (nod+ fix+).

Some strain variationNo clear link to nodA or genotype

Rhizobia isolated from introduced legumes(Bradyrhizobium spp.) could generally effectively nodulateother introduced legumes (nod+ fix+).

Rhizobia from gorse/broom was ineffective on Acacia (nod+

fix−).

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Rhizobia isolated from native legumes (Mesorhizobiumspp.) could generally effectively nodulate other nativelegumes (nod+ fix+).

Some strain variationNo clear link to nodA or genotype

Rhizobia isolated from introduced legumes(Bradyrhizobium spp.) could generally effectively nodulateother introduced legumes (nod+ fix+).

Rhizobia from gorse/broom was ineffective on Acacia (nod+

fix−).

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

No cross nodulation between rhizobia of native and exotics.Rhizobium leguminosarum formed ineffective nodules onnative legumes

Parasitic.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

No cross nodulation between rhizobia of native and exotics.Rhizobium leguminosarum formed ineffective nodules onnative legumes

Parasitic.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

No cross nodulation between rhizobia of native and exotics.Rhizobium leguminosarum formed ineffective nodules onnative legumes

Parasitic.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Which other legumes can native rhizobia nodulate?Most likely candidates are those that nodulate withMesorhizobium in other countries.Tested Astragalus membranaceus (milk vetch), Lotustetragonolobus (asparagus pea), Cicer arietinum (chickpea), Styphnolobium japonicum (Japanese pagoda tree)

Only Astragalus nodulated.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Which other legumes can native rhizobia nodulate?Most likely candidates are those that nodulate withMesorhizobium in other countries.Tested Astragalus membranaceus (milk vetch), Lotustetragonolobus (asparagus pea), Cicer arietinum (chickpea), Styphnolobium japonicum (Japanese pagoda tree)

Only Astragalus nodulated.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Which other legumes can native rhizobia nodulate?Most likely candidates are those that nodulate withMesorhizobium in other countries.Tested Astragalus membranaceus (milk vetch), Lotustetragonolobus (asparagus pea), Cicer arietinum (chickpea), Styphnolobium japonicum (Japanese pagoda tree)

Only Astragalus nodulated.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Results

Which other legumes can native rhizobia nodulate?Most likely candidates are those that nodulate withMesorhizobium in other countries.Tested Astragalus membranaceus (milk vetch), Lotustetragonolobus (asparagus pea), Cicer arietinum (chickpea), Styphnolobium japonicum (Japanese pagoda tree)

Only Astragalus nodulated.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Origin?

R. M. Greenwood (DSIR) 1960’s and 70’s.NZ rhizobia only effectively nodulate related legumes(Galegeae, Hedysareae, and Carmichaelinae tribes)Ineffective or do not nodulate all other tested species.

Exception: Sophora.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Origin?

R. M. Greenwood (DSIR) 1960’s and 70’s.NZ rhizobia only effectively nodulate related legumes(Galegeae, Hedysareae, and Carmichaelinae tribes)Ineffective or do not nodulate all other tested species.

Exception: Sophora.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Origin?

R. M. Greenwood (DSIR) 1960’s and 70’s.NZ rhizobia only effectively nodulate related legumes(Galegeae, Hedysareae, and Carmichaelinae tribes)Ineffective or do not nodulate all other tested species.

Exception: Sophora.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Origin?

R. M. Greenwood (DSIR) 1960’s and 70’s.NZ rhizobia only effectively nodulate related legumes(Galegeae, Hedysareae, and Carmichaelinae tribes)Ineffective or do not nodulate all other tested species.

Exception: Sophora.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

Phylogenetic analysesNodulation gene analysisHost-range testing

Origin?

R. M. Greenwood (DSIR) 1960’s and 70’s.NZ rhizobia only effectively nodulate related legumes(Galegeae, Hedysareae, and Carmichaelinae tribes)Ineffective or do not nodulate all other tested species.

Exception: Sophora.

ConclusionRhizobia travelled to NZ in association with their legume hostsfrom the centre of legume evolution in the northernhemisphere, to retain specificity.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Summary

Native legumes are nodulated by Mesorhizobium spp. thatare diverse, have novel nod genes, and nodulate onlyrelated species.

Rhizobia origin: Arrived 5+ mya, with legume ancestors.Introduced legumes are nodulated by Bradyrhizobium spp.that are diverse, and have nod genes similar to European(Gorse/Broom) and Australian (Acacia) species.

Rhizobia origin: Arrived recently, with human migration orwinds.

Future work:nodA genes of rhizobia nodulating NZ legume relatives.Structure of the nod factor, receptor, and other nod genes.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Summary

Native legumes are nodulated by Mesorhizobium spp. thatare diverse, have novel nod genes, and nodulate onlyrelated species.

Rhizobia origin: Arrived 5+ mya, with legume ancestors.Introduced legumes are nodulated by Bradyrhizobium spp.that are diverse, and have nod genes similar to European(Gorse/Broom) and Australian (Acacia) species.

Rhizobia origin: Arrived recently, with human migration orwinds.

Future work:nodA genes of rhizobia nodulating NZ legume relatives.Structure of the nod factor, receptor, and other nod genes.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Summary

Native legumes are nodulated by Mesorhizobium spp. thatare diverse, have novel nod genes, and nodulate onlyrelated species.

Rhizobia origin: Arrived 5+ mya, with legume ancestors.Introduced legumes are nodulated by Bradyrhizobium spp.that are diverse, and have nod genes similar to European(Gorse/Broom) and Australian (Acacia) species.

Rhizobia origin: Arrived recently, with human migration orwinds.

Future work:nodA genes of rhizobia nodulating NZ legume relatives.Structure of the nod factor, receptor, and other nod genes.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Summary

Native legumes are nodulated by Mesorhizobium spp. thatare diverse, have novel nod genes, and nodulate onlyrelated species.

Rhizobia origin: Arrived 5+ mya, with legume ancestors.Introduced legumes are nodulated by Bradyrhizobium spp.that are diverse, and have nod genes similar to European(Gorse/Broom) and Australian (Acacia) species.

Rhizobia origin: Arrived recently, with human migration orwinds.

Future work:nodA genes of rhizobia nodulating NZ legume relatives.Structure of the nod factor, receptor, and other nod genes.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Summary

Native legumes are nodulated by Mesorhizobium spp. thatare diverse, have novel nod genes, and nodulate onlyrelated species.

Rhizobia origin: Arrived 5+ mya, with legume ancestors.Introduced legumes are nodulated by Bradyrhizobium spp.that are diverse, and have nod genes similar to European(Gorse/Broom) and Australian (Acacia) species.

Rhizobia origin: Arrived recently, with human migration orwinds.

Future work:nodA genes of rhizobia nodulating NZ legume relatives.Structure of the nod factor, receptor, and other nod genes.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Implications for Biodiversity and Biosecurity

Biodiversity: Potentially help in the restoration ofClianthus.Biosecurity: Foreign rhizobia from imported goods andcommercial inoculants may enhance the growth of weeds.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Implications for Biodiversity and Biosecurity

Biodiversity: Potentially help in the restoration ofClianthus.Biosecurity: Foreign rhizobia from imported goods andcommercial inoculants may enhance the growth of weeds.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Implications for Biodiversity and Biosecurity

Biodiversity: Potentially help in the restoration ofClianthus.Biosecurity: Foreign rhizobia from imported goods andcommercial inoculants may enhance the growth of weeds.

Bevan Weir Origins of New Zealand’s Rhizobia

IntroductionResults and Discussion

Summary

ImplicationsAcknowledgements

Acknowledgements

My Phd Supervisors:Dr. John Young (Landcare Research)Dr. Susan Turner (Auckland University)Prof. Warwick Silvester (Waikato University)

Royal Society of New Zealand (Marsden Fund)Landcare Research

Bevan Weir Origins of New Zealand’s Rhizobia

Appendix References

References I

Weir, B. S., Turner, S. J., Silvester, W. B., Park, D.-C.,andYoung, J. M.Unexpectedly diverse Mesorhizobium strains andRhizobium leguminosarum nodulate native legume generaof New Zealand, while introduced legume weeds arenodulated by Bradyrhizobium species.Applied and Environmental Microbiology, 70(10):5980–5987, 2004.

Bevan Weir Origins of New Zealand’s Rhizobia