Achieving  sustainable  leaf  rust  control  in  durum  wheat:    What  have  we  learnt  and  how  to  move  forward  

 S.A.  Herrera-­‐Foessel,  R.P.  Singh,  J.  Huerta-­‐Espino,  V.  Calvo-­‐Salazar,  C.  Lan,  B.R.  

Basnet  and  E.S.  Lagudah    

BGRI  Workshop,  Cd.  Obregon,  23  March  2014  

Content  

� Background  ■  Dw,  losses  

� Resistance  ■  Resistance  in  general  ■  Race-­‐specific  or  major  gene-­‐based  ■  Slow  rusSng  

� Challenges  and  Future  prospects    

 

Durum wheat - Importance

50% 50%

% durum wheat area

developed world

developing world

80%

20%

% durum wheat cultivars in developing

countries CIMMYT-derived

Non-CIMMYT derived

80%

20%

% wheat area in Yaqui & Mayo valley year 2014

Cirno C2008

Other

Leaf  rust  -­‐  importance  

                                     Yield  losses  (%)*  Normal  planSng  

Late  planSng    

Across  trials  

Range   Range   Mean  Suscep-­‐Sble   33-­‐61   67-­‐74   60  

*Fungicide  protected  and  non-­‐protected  plots  under  high  disease  pressure,  Cd  Obregon  (Herrera-­‐Foessel  et  al.,  2006)  

� Before  BBG/BN  (<Year  2001)  ■ No  severe  leaf  rust  epidemics  reported  ■ CulSvars  resistant  ■ Not  much  known  on  geneSc  basis  of  resistance  ■ Of  Lr  genes  designated  -­‐  few  of  durum  origin  ■ Not  known  whether  bread  wheat  and  durum  wheat  shared  the  same  resistance  genes  

 

Leaf  rust  resistance  in  durum  wheat  

80%

20%

Cultivars from 31 different countries

Lr72

Other

Leaf rust resistance in Altar C84: Lr72

Atre

d

Atil

200

0

Alta

r 84

P. tritcina MBJ/SP

Singh  et  al  2004  

Herrera-­‐Foessel  et  al  2013    

US$ 32 M BBG/BN  

Major leaf rust resistance genes identified at CIMMYT effective to BBG/BN

Lrgene   Chr   Origin   CulKvar/line  3   6BLa   T.  aes*vum   Storlom  14a   7BLb   T.  turgidum  ssp.  dicoccum   Llareta  INIA,  Somateria,  Cevi  Oro  C2008,  

Patronato  Oro  C2008,  Sawali  Oro  C2008    27+31   3B+4Bc   T.  aes*vum   Jupare  C2001,  Banamichi  C2004  61   6BSd   T.  turdigum  ssp.  durum   Guayacan  INIA,  Guayacan  2  Camayo   6BLa   T.  turdigum  ssp.  durum   Camayo,  Cirno  C2008  

a  Herrera-­‐Foessel  et  al  2007a  b  Herrera-­‐Foessel  et  al  2008a  c  pers.  comm  d  Herrera-­‐Foessel  et  al  2008b  

DW-­‐specific  P.  tri(cina  races  idenKfied  in  Mexico  since  1988      

LrCamayo    Lr14a  

Year  of  release  and  year  of  breakdown  of  leaf  rust  resistance  of  important  culKvars  from  northwestern  Mexico CulKvar   Wheat   Year   Gene   Race  Yecora  70   BW   1973   Lr1,  13   ?  Tanori  71   BW   1975   Lr13,  17   ?  Jupateco  73   BW   1977   Lr17,  27+31   TBD/TM  Genaro  81   BW   1984   Lr13,  26   TCB/TB  Seri  82   BW   1985   Lr23,  26   TCB/TD  Baviacora  92   BW   1994   Lr27+31,  APRa    MCJ/SP  Altar  84   DW   2001   Lr72   BBG/BN  Jupare  2001   DW   2008   Lr27+31   BBG/BP  Cirno  C2008   DW   ?   LrCam   ?  

a  Unknown  race-­‐specific  adult  plant  resistance  gene    

AddiKonal  major  leaf  rust  resistance  genes  known  to  be  present  in  durum  wheat      

Lr  gene   Chr   Origin   Reference  10a   1AS   T.  aes*vum   Aguilar-­‐Rincon  et  al.  2001;  B.  Keller  (pers.  

comm.)  19b   7A   Lophopyrum  pon*cum   Zhang  et  al.  2005;  Gennaro  et  al.  2009  23a   2B   T.  turdigum  ssp.  durum   Watson  and  Luig  1961  33a   1B   T.  aes*vum/T.  turgidum  ssp.  

dicoccoides  Dyck  1994;  Dyck  and  Bartos  1994  

37b   2AS   T.  ventricosa   Helguera  et  al.  2003  47   7AS   T.  speltoides   Dubcovsky  et  al.  1998    52   5BS   T.  aes*vum   Singh  et  al.  2010  64   6AL   T.  turgidum  ssp.dicoccoides   R.A.  McIntosh  (pers.comm)  ac127   4A   T.  turdigum  ssp.  durum   Hussein  et  al.  2005  

a Virulence common among durum specific races b Virulence already present among bread wheat specific races

Resistance  sources:  Slow  rusKng  

� Few  geneSc  studies  (Singh  et  al  1993)  made  before  Lr72  was  overcome,  since  this  gene  was  present  in  most  durums  

� New  slow  rusSng  sources  that  reduced  yield  losses  idenSfied  (Singh  et  al  2004;  Herrera-­‐Foessel  et  al  2006)  

� Post-­‐flowering  leaf  Sp  necrosis  

 

GeneKc  analysis  of  CIMMYT  slow  rusKng  lines    

■ Based  on  2-­‐3  minor  genes  with  addiSve  effect  ■ Narrow  geneSc  base  ■ Transgressive  segregaSon  

 Herrera-­‐Foessel  et  al  2008c  

Pyramiding  slow  rusKng  resistance  genes    

0

20

40

60

80

100

120

ATIL C

2000

a (Che

ck)

ATIL*2

/LOCAL R

EDa (Che

ck)

PIQUEROb

BERGANDb

AMICb

KNIPAb

TAGUAb

TRILE

b

PLANETA

b

PLAYEROb

PLAY/B

ERG//PIQ

/AMIC_6

0c

PLAY/B

ERG//PIQ

/AMIC

_64c

PLAN/AMIC

//BERG/TR

ILE_9

1c

PLAN/A

MIC//B

ERG/TRILE

_96c

PLAN/KNIPA//B

ERG/TAGUA_1

00c

BERG/AMIC

//PLA

Y/PIQ

_125

c

BERG/AMIC

//PLA

Y/PIQ_1

26c

CIMMYT Slow rusting durum wheats

% L

eaf r

ust

0

500

1000

1500

2000

2500

Are

a U

nit

FDSAUDPC

A x B C x D F1 x F1

GeneKc  analysis  of  slow  rusKng  resistance  

PopulaSon   HPTR   HPTS   OTHER   TOTAL  No  genes  

P-­‐value  

ATREDa/HELLER  #1b   4   6   125   135   4   0.82  

ATRED/BAIRDSc   9   4   127   140   4   0.21  

ATRED/DUNKLERd   5   2   118   125   4   0.46  a  ATRED  =  ATIL*2/LOCAL  RED  

b  HELLER  #1  =  PLAYERO/BERGAND//PIQUERO/AMIC  c  BAIRDS  =  BERGAND/AMIC//PLAYERO/PIQUERO  e  DUNKLER  =  AMIC/TRILE//PLANETA/PIQUERO  

No.  genes  esSmated-­‐  Cd.  Obregon  2013  

Genomic regions associated with slow rusting resistance

�  IdenSficaSon  of  Lr46/Yr29/Sr58/Ltn2  in  durum  wheat  using  Atred  #1  x  ASl  C2000  RIL  populaSon  and  CSIRO  marker  csLV46G22  

Chromosome   References  

2AL,  3AS,  7BS  Maccaferri  et  al  2008  

2AL,  2BS,  4BL,  5A   Marone  et  al  2009  

2BL,  3BS,  7BS  Maccaferri  et  al  2010  

1B,  2B,  4B,  7B   Singh  A  et  al  2012    Cd.  Obregon  2013,  significant  difference  at  P<0.05  

49

29 43

35 12 26

-LR46/YR29 +LR46/YR29 SEGREGATING % R

ust s

ever

ity

Mean % rust severity for RILs of Atil C2000 x Atred #1 population

Leaf rust Stripe rust

�  Reported  minor  QTLs/slow  rusSng  resistance?  

       

3

10

18

11 13

4 1

Num

ber r

etai

ned

entri

es

Yield % over check cultivar Cirno C2008

Yield trials in Y12-13

Breeding  for  high  yielding  durable  leaf  rust  resistant  germplasm    � Slow  rusKng  DW  developed  from  backcrosses  with  AKl  

C2000  retained  (n=57)  from  1st  year  yield  trial  at  Cd  Obregon  2013  

AddiKonal  studies  on  slow  rusKng  resistance  

� EvaluaKon  of  macroscopic  components:  latency  period,  recepKvity,  uredinium  size  ■  MarSnez  et  al  2001;  Herrera-­‐Foessel  et  al  2007b;  MarSnez  et  al  2007;  Marone  et  al  2009;  Soleiman  et  al  2013  

� EvaluaKon  of  microscopic  components:  No.  early  aborted  infecKon  units  (-­‐),  relaKve  colony  size  ■  Marone  et  al  2009;  Soleiman  et  al  2013  

Strategies  and  future  challenges  

� GeneKc  diversity  essenKal  � Vulnerability  to  rely  on  few  major  genes  (LrCam  or  

Lr14a)  � Slow  rusKng  resistance-­‐a  more  durable  soluKon  � The  narrow  geneKc  base  of  CIMMYT  durum  wheats  

implies  that  other  sources  should  be  invesKgated  � Exploit  variability  from  landraces  or  related  tetraploids  

to  enhance  diversity  and  achieve  higher  levels  of  resistance  

Pt race BBG/BP

Accession Seedling infection type

Field severity & reaction

LTN

OAX93.6.20 3+4 5MS 2 OAX93.6.30 X- 1MS 2 OAX93.6.81 3+ 5MS 2 OAX93.8.2 X+ 5MS 2 OAX93.8.40 3+4 10MS 2 OAX93.8.46 3+ 10MS 1 OAX93.8.47 3+ 10MS 2 OAX93.8.51 3+4 15MS 2 OAX93.9.7 3+4 10MS 2 OAX93.9.9 3+4 5MS 2 OAX93.16.47 X 1MRMS 2 OAX93.18.18 X+3C 1MR 2

New  sources  of  resistance  

Cd.  Obregon  2013  

Strategies  and  future  challenges  

� Transfer  of  Lr68  from  bread  wheat    � Lr34  and  Lr67,  located  in  the  D-­‐genome    � Molecular  characterizaKon  of  slow  rusKng  resistance  

needed  ■  Increase  knowledge    ■  MAS  

� Strengthening  strategic  effort  to  breed  for  APR  resistance  in  durum  wheat  (require  absence  of  major  genes)  

     

Acknowledgements  

� CIMMYT’s  technical  staff  

� GRDC  Australia  

� Sida-­‐Sweden  

� SAGARPA-­‐CONACYT-­‐Mexico