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

Transcription

1 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

2 Content Background Dw, losses Resistance Resistance in general Race- specific or major gene- based Slow russng Challenges and Future prospects

3 Durum wheat - Importance % durum wheat area 50% 50% developed world developing world % wheat area in Yaqui & Mayo valley year % Cirno C % Other % durum wheat cultivars in developing countries 20% 80% CIMMYT-derived Non-CIMMYT derived

4 Leaf rust - importance Normal plansng Yield losses (%)* Late plansng Across trials Range Range Mean Suscep- Sble *Fungicide protected and non- protected plots under high disease pressure, Cd Obregon (Herrera- Foessel et al., 2006)

5 Leaf rust resistance in durum wheat 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

6 Leaf rust resistance in Altar C84: Lr72 BBG/BN US$ 32 M Atred Atil 2000 Altar 84 Cultivars from 31 different countries 20% 80% Lr72 Other P. tritcina MBJ/SP Herrera- Foessel et al 2013 Singh et al 2004

7 Major leaf rust resistance genes identified at CIMMYT effective to BBG/BN Lrgene Chr Origin CulKvar/line 3 6BL a T. aes*vum Storlom 14a 7BL b T. turgidum ssp. dicoccum Llareta INIA, Somateria, Cevi Oro C2008, Patronato Oro C2008, Sawali Oro C B+4B c T. aes*vum Jupare C2001, Banamichi C BS d T. turdigum ssp. durum Guayacan INIA, Guayacan 2 Camayo 6BL a 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

8 DW- specific P. tri(cina races idenkfied in Mexico since 1988 LrCamayo Lr14a

9 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, TBD/TM Genaro 81 BW 1984 Lr13, 26 TCB/TB Seri 82 BW 1985 Lr23, 26 TCB/TD Baviacora 92 BW 1994 Lr27+31, APR a 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

10 AddiKonal major leaf rust resistance genes known to be present in durum wheat Lr gene Chr Origin Reference 10 a 1AS T. aes*vum Aguilar- Rincon et al. 2001; B. Keller (pers. comm.) 19 b 7A Lophopyrum pon*cum Zhang et al. 2005; Gennaro et al a 2B T. turdigum ssp. durum Watson and Luig a 1B T. aes*vum/t. turgidum ssp. Dyck 1994; Dyck and Bartos 1994 dicoccoides 37 b 2AS T. ventricosa Helguera et al AS T. speltoides Dubcovsky et al BS T. aes*vum Singh et al AL T. turgidum ssp.dicoccoides R.A. McIntosh (pers.comm) ac127 4A T. turdigum ssp. durum Hussein et al a Virulence common among durum specific races b Virulence already present among bread wheat specific races

11 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

12 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

13 Pyramiding slow ruskng resistance genes A x B C x D F1 x F1 % Leaf rust ATIL C2000a (Check) ATIL*2/LOCAL REDa (Check) 0 PIQUEROb BERGANDb AMICb KNIPAb TAGUAb TRILEb PLANETAb PLAYEROb PLAY/BERG//PIQ/AMIC_60c PLAY/BERG//PIQ/AMIC_64c PLAN/AMIC//BERG/TRILE_91c CIMMYT Slow rusting durum wheats FDS AUDPC PLAN/AMIC//BERG/TRILE_96c PLAN/KNIPA//BERG/TAGUA_100c BERG/AMIC//PLAY/PIQ_125c BERG/AMIC//PLAY/PIQ_126c Area Unit

14 GeneKc analysis of slow ruskng resistance No. genes essmated- Cd. Obregon 2013 PopulaSon HPTR HPTS OTHER TOTAL No genes P- value ATRED a /HELLER #1 b ATRED/BAIRDS c ATRED/DUNKLER d 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

15 Genomic regions associated with slow rusting resistance Reported minor QTLs/slow russng resistance? IdenSficaSon of Lr46/Yr29/Sr58/ Ltn2 in durum wheat using Atred #1 x ASl C2000 RIL populason and CSIRO marker cslv46g22 Chromosome 2AL, 3AS, 7BS References Maccaferri et al AL, 2BS, 4BL, 5A Marone et al 2009 Maccaferri et al 2BL, 3BS, 7BS B, 2B, 4B, 7B Singh A et al 2012 % Rust severity Cd. Obregon 2013, significant difference at P< LR46/YR29 +LR46/YR29 SEGREGATING Mean % rust severity for RILs of Atil C2000 x Atred #1 population Leaf rust Stripe rust

16 Breeding for high yielding durable leaf rust resistant germplasm Slow ruskng DW developed from backcrosses with AKl C2000 retained (n=57) from 1 st year yield trial at Cd Obregon 2013 Number retained entries Yield % over check cultivar Cirno C2008 Yield trials in Y12-13

17 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

18 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

19 New sources of resistance Pt race BBG/BP Accession Seedling infection type Field severity & reaction LTN Cd. Obregon 2013 OAX MS 2 OAX X- 1MS 2 OAX MS 2 OAX X+ 5MS 2 OAX MS 2 OAX MS 1 OAX MS 2 OAX MS 2 OAX MS 2 OAX MS 2 OAX X 1MRMS 2 OAX X+3C 1MR 2

20 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)

21 Acknowledgements CIMMYT s technical staff GRDC Australia Sida- Sweden SAGARPA- CONACYT- Mexico