Determination of Physiological Races

小种鉴定及品种抗性鉴定

J

Phytopathol

SHORTCOMMUNICATION

DeterminationofPhysiologicalRacesandEvaluationofSun?owerforResistancetoPucciniahelianthiSchwLanJing1,XinXu1,JialiJing1,LiLi1andShrishailS.Navi2

1DepartmentofPlantPathology,InnerMongoliaAgriculturalUniversity,Hohhot010019,China

2DepartmentofPlantPathologyandMicrobiology,IowaStateUniversity,Ames,IA50011,USA

Keywords

physiologicalraces,PucciniahelianthiSchw.,

resistanceevaluation,sun?ower

Correspondence

L.Jing,DepartmentofPlantPathology,Inner

MongoliaAgriculturalUniversity,Hohhot,

China.

E-mail:jinglan71@http://wendang.chazidian.com

Received:January18,2014;accepted:June

19,2014.

doi:10.1111/jph.12296AbstractSun?owerrust,causedbyPucciniahelianthiSchw.,isawidespreaddiseaseofsun?ower(HelianthusannuusL.)inChina.Tostudyphysiologicalraces,sun?ower?eldsurveyswereundertakeninmajorsun?owergrowingareasofChinain2010.Forty-fourrust-infectedsun?owerleafsampleswerecollectedfrom25geographicallocations.Freshlyproducedsporeswereusedtostudyphysiologicalracedifferentiationonasetofninedifferentials.Race300wasthemostprevalentraceobservedoverallloca-tionswitha59%frequencyfollowedbyraces735,310,500,724and737.Toevaluatehybridsandvarietiesforresistancescreening,sporesofrace300wereusedtoinoculate65hybrids,and?veopen-pollinatedvarietiesselectedfrombreedingprogrammesandfromtheseedmarket.Noneof

theconfectionhybridsandopen-pollinatedvarietieswasimmunetorace

300.Conversely,amongoilseedhybrids,3%ofthemshowedimmunity,

12%highlyresistant,59%resistantand26%showedsusceptiblereac-

tions.Open-pollinatedvarietieswerethemostsusceptibletorace300fol-

lowedbyconfectionandoilseedsun?owerhybrids.Resultsfromthis

studyareprojectedtoassistbreedersinselectionofhybridsandvarieties

againstprevalentraceasourresultsshowedadiversityofresistancelevels

torace300.

Introduction

Sun?ower(HelianthusannuusL.)rankssecondinthe

worldforedibleoilproductionandisproducedin

Argentina,China,Russia,France,Ukraine,United

States,Spain,India,Turkey,RomaniaandHungary

(Anonymous2010).Sun?owerrust,causedbyPucci-

niahelianthiSchw.,isamacrocyclic,heterothallicand

autoeciousrustthatoccursonwildperennial,wild

annualandcultivatedHelianthusspp.(Markelletal.

2009).

Pucciniahelianthiisaheterothallicfungus;itsall?ve

sporestagesoccuronsun?owerresultinginfrequent

sexualrecombinationleadingtotheemergenceof

newraces.Althoughfungicidesareavailablefordis-

easemanagement(Gulyaetal.1997),hostplant

resistanceisthemosteffectiveandeconomicwayto

controlthedisease.Theconstantpresenceofruston

JPhytopathol163(2015)507–512Ó2014BlackwellVerlagGmbHwildHelianthusannuus(GulyaandViranyi1994)hasleadtotheevolutionofrustresistanceinwildspecies(Gulyaetal.2000),andthishasservedasavaluablesourceofrust-resistantgenesforcultivatedsun?ower(MillerandGulya2001).Monitoringrustpathotypesiscriticaltode?nebreedingstrategies.Therefore,asurveyofrustphysio-logicalraceswasconductedto:(i)gatherinformationonthediversityofthispathogentodeterminethegene(s)thatarestillappropriateforintrogressingintothesun?owerbreedingprogrammesand(ii)toevaluateselectedsun?owerhybridsandvarietiesforresistancetothepredominantraceinChina.Resultsfromtheseobjectives,anticipatedtohelptoimproveresistance-breedingprogrammestothisdiseaseandincreasemarketshareofgeneticallyimprovedvarie-tiesandhybridswithincreasedyieldspotentialcombinedwithrustresistancecomponent.507

小种鉴定及品种抗性鉴定

Rustracesandsourcesofresistanceinsun?owerMaterialsandMethods

Forty-fourrust-infectedleaveswerecollectedfromvolunteersun?owerplants,experimentalplotsandcommercial?eldsfrom25geographicallydifferentlocationsina?eldsurveyduring2010(Table1).Fromeachcollection,urediosporesampleswereincreasedbyinoculatingsingleurediniosporeisolatesonsusceptiblegenotype7350.Thesporesofeachiso-lateweredesiccatedandstoredindividuallyinliquidnitrogenat80°Cbelowzero.

Physiologicalracesandvirulencepatternswereidenti?edbyusingasetofninedifferentialspublishedbyGulyaandMasirevic(1996)andtheassociatedcodedtripletnomenclature(GulyaandMasirevic1995).Seedsofthedifferentiallines7350,CM90,CM29,P386,HA-R1,HA-R2,HA-R3,HAR-4andHAR-5weresurfacedisinfectedin1%sodiumhypo-chlorite,andeachplantedin?vepots(?veseedsperpot)containingpasteurizedsoil(atotalof45potseachwith?veplants).Urediopsoreconcentrationofeachisolatewasadjustedto19106/mlofwaterusingahaemocytometer,andtheindividualisolatesweresmear-inoculatedusinga?atcamelhairbrush,separately,ontoV2stageseedlingsofthedifferentialset.Theinoculatedseedlingswereincubatedat20°Cinadewchamberfor20hinthedarkpriortobeing

Table1Collectionofsun?owerleavesinfectedbyrust(Pucciniahelianthi)duringsurveysconductedduring2010SampleSamplenumberLocation

numberLocation1

Manzhouli,

26

Hangjingqi,IMAR

InnerMongoliaAutonomousRegion(IMAR)2,3Arongqi,IMAR27Hangjinghouqi,IMAR4Zalantun,IMAR28Wulateqianqi,IMAR5,6Wulanhaote,IMAR29,30Gannan,Heilongjiangprovince

7Keyouqianqi,IMAR31–33Zhangjiakou,Hebeiprovince8–11Zaluteqi,IMAR34,35Yinchuan,NingxiaAutonomousRegion12,13Tongliao,IMAR36,37Mizhi,Shaanxiprovince14–16Naimanqi,IMAR38Dingbian,Shaanxiprovince17Chifeng,IMAR39–41Weinan,Shaanxiprovince18,19Hohhot,IMAR42Angelige,XinjiangAutonomousRegion20Tuzuoqi,IMAR43Shihezi,Xinjiang

AutonomousRegion21–24Salaqi,IMAR44

Aletai,Xinjiang

AutonomousRegion

25

Dalate,IMAR

508

L.Jingetal.

shiftedtoagreenhousebenchat22Æ2°Cwitha16-hphotoperiod.Sodiumvapourlampswereusedforsupplementalillumination.Fourteendaysafterincu-bation,thedifferentialswereevaluatedforinfectiontypeanddevelopmentofrustsymptomsfollowingtheinfectiontypescaleofYangetal.(1986).Fiveinfec-tiontypesareasfollows:

0:immune,nourediaorhypersensitive?ecks.

1:veryresistant,producinghypersensitive?ecksorverysmall(<0.2mm),sparselysporulatingpustules.2:resistant,producingsmall(<0.4mm),weaklyspor-ulatingpustules.

3:susceptible,pustules0.4–0.6mmindiameterwithvigorouslysporulation.

4:verysusceptible,pustules>0.6mmandmanycoa-lesced.

Reactions0,1and2wereregardedasresistant,and3and4assusceptible.Thisexperimentwasrepeatedoncewith45potseachwith?veplants.

Sixty-?vehybrids(31confectionsand34oilseeds),and?veopen-pollinatedvarieties(Table3)obtainedfrombreedingunitsandtheseedmarketwereassessedforresistanceagainstthepredominantrustrace300.Methodsofplanting,inoculation,incuba-tionandevaluationweresimilartothemethodsexplainedindeterminationofphysiologicalraces.Basedonreactiontype,hybridsandvarietieswereclassi?edas0=immune,1=highlyresistant(HR),2=resistant(R),3=susceptible(S)and4=highlysusceptible(HS)andthehybridsandvarietiesclassi-?edaccordingly.Water-sprayedplantsservedascontrols.

ResultsandDiscussion

InnerMongoliaisthelargestsun?owergrowingareainChina,andmostoftherustsamplesinthisstudywerecollectedfromthisarea.Basedontheinfectiontypeanddevelopmentoftherustsymptomsondiffer-entials,14daysafterincubation,thephysiologicalracesweredeterminedfollowingthecodedtripletnomenclaturesystem.Inthisstudy,race300wasthemostcommonraceobservedinsamplescollectedfrom25locationswith59%prevalencefollowedbyraces735,310,500,724and737(Table2).Distribu-tionofrace735wasobservedinsamplescollectedfromInnerMongoliaandShaanxi,race310inisolatescollectedfromcentralandeasternregionsofInnerMongolia,HebeiandNingxia,race500ineasternInnerMongolia,race737and724inShaanxiandsouth-westernInnerMongolia,respectively(Fig.1).Resultsofthisstudymayassistbreedersindeveloping

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小种鉴定及品种抗性鉴定

L.Jingetal.Rustracesandsourcesofresistanceinsun?owerTable2Identi?cationofPucciniahelianthiracesprevalentinmajor

sun?owergrowingareasinChina

Rustraces,prevalence(%)and

reaction(SorR)

300

59%

S

S

R

R

R

R

R

R

R31014%SSRSRRRRR5007%SRSRRRRRR7242%SSSRSRRRS73516%SSSSSRSRS7372%SSSSSRSSSSun?owerdifferentiallines(codedvalue)7350(1)CM90(2)CM29(4)P386(1)HA-R1(2)HA-R2(4)HA-R3(1)HA-R4(2)HA-R5(4)

R,Resistant;S,

Susceptible.

hybridsandvarietiesthatareresistanttorustina

particulargeographicaldistributionofrustracesin

differentpartsofChina.Theoccurrenceofdifferentphysiologicalracesofsun?owerrustinChinawas?rstreportedin1993(ZhangandLi).Sincethen,thereportsofvariabilityofthispathosystemwerescarce.In1996,thephysio-logicalraces2,3,newisolatesCL1,CL3andCL4weredeterminedwithrace3,theprevalentraceupto90%(Zhangetal.1996).Eightmajorvarietiesand37confectionhybridswereevaluatedfortheirresistance.Theresultsoftheevaluationshowedalltobesuscep-tibletorace3(Zhangetal.1996).ThepreviouslyreportedNorthAmerican(NA)race1correspondedtorace100ofthenewcodedtripletsystem,NArace2torace500,NArace3torace300andNArace4torace700(Qietal.2011).InarecentstudybyCao(2011)where10isolatesofP.helianthiwerecollectedfromJilinProvince(onthenorth-eastofInnerMongolia),race1(100),race2(500),race3(300)andrace5(334)werereported.Amongtheseraces,race2waspredominant.IntheUnitedStatesofAmerica,59rustsampleswerecollectedfrom2002to2005,25differentracesFig.1Distributionofsun?owerrustracesamongtheisolatescollectedfrom25diversegeographicalareasofChina.

JPhytopathol163(2015)507–512Ó2014BlackwellVerlagGmbH509

小种鉴定及品种抗性鉴定

Rustracesandsourcesofresistanceinsun?owerL.Jingetal.

wereidenti?ed.35%oftheisolateswereraces100,510and700,and2–7%ofthepopulationwereother22races(Gulya2006).In2008,thirty-nineNArustraceswereidenti?edofwhichraces334and336weremostprevalent,andthemajorityofcommercialhybridsweresusceptibletotheseraces(GulyaandMarkell2009).AnewlyevolvedNArustrace777col-lectedinTexasandKansas,wasabletoinfectallninedifferentials,butremainedatalowfrequency.Race777canpotentiallycauseseriousepidemicsifitbecomesprevalentinNorthAmerica(Qietal.2012).Similarly,17rustisolatescollectedinArgentinaduring2004–2011werefoundtoconsistofraces700,704,720,740,744,760ofwhich700wasthepre-dominantrace,indicatingthattherewasasigni?cantchangeinthecompositionofthephysiologicalracesofP.helianthiinArgentina(Morenoetal.2012)sincethepublicationofthelastsurveyin1985(Antonelli).Inourstudy,59%oftheisolatescollectedbelongtorace300.Fortunately,wedidnotobservethevirulentrace777,however,wedidobserve2%eachofraces724and737and16%ofrace735.Thissuggeststhatcontinuoussurveysofrustracesthroughoutthesun-?owercultivationregionsinChinaarenecessaryin

Table3Evaluationofsun?owerhybridsandopen-pollinatedvarietiesforresistancetorace300Hybridsandopen-pollinatedvarietiesOilseedsun?ower

Hybrid

ReactiontypeImmuneChi0299115R

HighlyresistantA18S510Xinkui10

Xinkuihybrid5

Resistant658

Chi128A9116RChiCY102ChiKY11-06ChiKY11-46ChiKY11-52CY101F08-2F60

LiaofengF53Longkuihybrid1Lonkuihybrid1MGSNC-209S26S27S31S49S67YF-168

1189W313638CBakui118Bakui138BY11-45Chi3009

Chi407292RGan10138JK108LD1355LD5009

Longshikui2Longshikui3RH118RH314Chikui236

Susceptible571519522847K152

ChiKY11-23GKSO9-2JK102

Longkuihybrid2S18

Xinkuihybrid6Yikuihybrid3

Highlysusceptible

Confectionsun?owerHybrid

JK518KS1KS2SH6009T33

767CJK103JK105JK106JK107Keyang7LSK11LSK12RH318SH909

Gankui2

OPvariety

Total

1

9JingxuangankuiJinkui721HeidapianSandaomei3

510

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小种鉴定及品种抗性鉴定

L.Jingetal.assistingbreedingprogrammesindevelopingresistantsourcesandintrogressionstrategies.

Among65hybrids(31confectionsand34oilseeds)and?veopen-pollinatedvarieties,onlyfouroilseedhybridsand?veconfectionhybridsshowedhighresistanceandonlyoneoilseedhybridshowedimmunereactionstorace300(Table3).Similarly,20oilseedhybrids,15confectionhybridsandoneopen-pollinatedvarietyshowedresistancereactions.Onlyoneconfectionhybridandtwoopen-pollinatedvarie-tiesshowedhighlysusceptiblereaction,andnineoil-seedhybrids,12confectionhybridsandtwoopen-pollinatedvarietiesshowedsusceptiblereactionstorace300(Table3).Inotherwords,amongoilseedhybrids,3%ofthemremainedimmune,12%werehighlyresistant,59%wereresistantand26%ofthemshowedsusceptiblereactionstorace300(Fig.2).Similarly,mostsusceptiblereactionstorace300wereobservedamongopen-pollinatedvarietiesfollowedbyconfectionandoilseedsun?owerhybrids(Fig.2).Inthecurrentstudy,wedidobserveopen-polli-natedvarietiesandconfectionhybridsshowingmoresusceptibilitytorace300comparedwithoilseedhybrids,whichisinagreementwithFriskopetal.(2011).Confectionsun?owerseedsareaverypopularsnackfoodforChinese,andexceed40%ofthetotalsun?owerproductionareainChina.Somefarmerspreferplantingopen-pollinatedconfectionsun?owerforqualitysnacksandcompetitiveseedprices.Withmoreandmoreconfectionhybridsandopen-polli-natedvarietiesplanted,susceptibilitytorustisofgreaterconcerntobothbreedersandpathologists.Thismightcausechangesinracepatternsofthe

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Rustracesandsourcesofresistanceinsun?ower

pathogeninChina,similartothereportsbyFriskopetal.(2011).Therefore,monitoringthedevelopmentofnewracesthroughregularsurveyswillcertainlyhelpbreedersindevelopingrust-resistantsun?owergermplasmintheabsenceoftheavailabilityofsuit-able,economicalandenvironmentallyfriendlychem-icalstomanagethisdisease.Acknowledgements

TheauthorsthankMr.ThomasJ.GulyaatARSofUSDAforprovidingseedsofthedifferentiallines.ThisresearchwasfundedbytheNationalNaturalScienceFoundationofChina(31060235and31360422)ChinaAgriculturalResearchSystem(CARS-16).References

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