Resistance against barley leaf rust (Puccinia hordei) in West-European spring barley germplasm

HAL Id: hal-00886084 h ps://hal.a chi es-ou e es. /hal-00886084 Submi ed on 1 Jan 2000 HAL is a mul i-disciplina y open access a chi e o he deposi and dissemina ion o sci- en i ic esea ch documen s, whe he hey a e pub- lished o no . The documen s may come om eaching and esea ch ins i u ions in F ance o ab oad, o om public o p i a e esea ch cen e s. L’a chi e ou e e plu idisciplinai e HAL, es des inée au dépô e à la di usion de documen s scien i iques de ni eau eche che, publiés ou non, émanan des é ablissemen s d’enseignemen e de eche che ançais ou é ange s, des labo a oi es publics ou p i és. Resis ance agains ba ley lea us (Puccinia ho dei) in Wes -Eu opean sp ing ba ley ge mplasm Rien s Niks, U sula Wal he , Heidi Jaise , Fe nando Ma inez, Diego Rubiales To ci e his e sion: Rien s Niks, U sula Wal he , Heidi Jaise , Fe nando Ma inez, Diego Rubiales. Resis ance agains ba ley lea us (Puccinia ho dei) in Wes -Eu opean sp ing ba ley ge mplasm. Ag onomie, EDP Sciences, 2000, 20 (7), pp.769-782. <10.1051/ag o:2000174>. <hal-00886084> Plan Gene ics and B eeding O iginal a icle Resis ance agains ba ley lea us (Puccinia ho dei) in Wes -Eu opean sp ing ba ley ge mplasm Rien s E. NIKSa*, U sula WALTHERb, Heidi JAISERc, Fe nando MART Í NEZd, Diego RUBIALESd, Ole ANDERSEN**, Ke s in FLATH**, Paul GYMER**, F i z HEINRICHS**, Ricka d JONSSON**, Lissy KUNTZE**, Mo en RASMUSSEN**, Edel au RICHTER** a Labo a o ium oo Plan en e edeling, Wageningen Uni e si y, Pos bus 386, 6700 AJ Wageningen, The Ne he lands b Bundesans al ü Züch ungs o schung an Kul u p lanzen, Theodo Roeme -Weg 4, 4320 Asche sleben, Ge many c Pajbje g onden, Ge sdo slund ej 1, Hou, 8300 Odde , Denma k d Ins i u o Ag icul u a Sos enible, CSIC, Apdo 4084, 14080 Có doba, Spain (Recei ed 28 Ap il 2000; e ised 9 July 2000; accep ed 15 Augus 2000) Abs ac – The le el and ype o esis ance agains lea us (Puccinia ho dei) was de e mined in mode n sp ing ba ley ge mplasm. In ield ials all o e Eu ope mos accessions we e in some loca ions and yea s signi ican ly less in ec ed han he mode a ely esis an e e ence ‘G i ’. Di e en ia ing P. ho dei isola es indica ed ha mos accessions ca ied hype sensi i i y (Rph) genes. A i ulence su ey indica ed ha among he known esis ance genes, only Rph7 is s ill ully e ec i e in Eu ope. Some accessions ca ied unde e mined hype sensi i i y esis ance gene(s) ha we e e ec i e o all isola es es ed. The le el o non-hype sensi i i y o pa ial esis ance was assessed om he la ency pe iod o he ungus and he pe cen age o ea ly abo ed in ec ion uni s no associa ed wi h plan cell nec osis. These pa ame e s indi- ca ed ha se e al accessions had a le el o pa ial esis ance highe han ha o he highly pa ially esis an ‘Vada’. We concluded ha ba ley b eede s ha e achie ed e y high le els o pa ial esis ance agains P. ho dei in sp ing ba ley ge mplasm. ba ley / lea us / pa ial esis ance / i ulence / hype sensi i i y Résumé – Résis ance à la ouille b une (Puccinia ho dei) du ge mplasme d’o ge de p in emps d’Eu ope de l’oues . Le ni eau e le ype de ésis ance con e la ouille b une (Puccinia ho dei) on é é dé e miné chez le ge mplas- me d’o ge de p in emps. Dans des champs expé imen aux p ésen s dans l’Eu ope en iè e, la plupa des accessions on é é pou ce ains si es e années, moins in ec ées compa é à la é é ence ‘G i ’ qui es modé émen ésis an e. Des iso- la s de P. ho dei di é enciés on indiqué que la plupa des accessions con enaien les gènes d’hype sensi i i é Rph. Un es de i ulence a indiqué que des gènes Rph connus, seul Rph7 es enco e complè emen e icace en Eu ope. Ce aines Ag onomie 20 (2000) 769–782 769 © INRA, EDP Sciences 2000 Communica ed by Hanne Øs e gå d (Roskilde, Denma k) * Co espondence and ep in s [email p o ec ed] ** A ilia ions a e in Appendix R.E. Niks e al. 770 1. In oduc ion Ba ley lea us , caused by Puccinia ho dei O h, occu s whe e e ba ley (Ho deum ulga e L.) is cul i a ed. The economic impo ance o he us depends on he egion in he wo ld, and a ies om yea o yea . In Eu ope, he disease is gene - ally mo e impo an in he empe a e and wa me egions, like he Uni ed Kingdom and F ance, and less so in he mo e no he n pa s o Eu ope. In 1998 and 1999, o example, lea us was among he mos impo an ba ley pa hogens in he UK (Cla kson, NIAB, Camb idge, UK, pe s. comm.). Losses o abou 10 o 25% ha e been ci ed o he Czech Republic [3]. I appea s ha he economic impo ance o ba ley lea us has inc eased in ecen yea s [2, 4]. In Eu ope, a me s apply epea ed ungicide ea men s on ba ley o p o ec agains ungal lea pa hogens, including ba ley lea us . The e is inc easing opposi ion o he applica ion o pes i- cides in ag icul u e, because o he en i onmen al and heal h isks. The mos ob ious al e na i e o ungicide ea - men is he use o esis an cul i a s. Resis ance in ba ley o P. ho dei is widely a ailable. The e a e wo ypes o esis ance o his pa hogen: hype sen- si i i y esis ance and non-hype sensi i i y esis- ance [1]. The hype sensi i i y esis ance is go - e ned by majo genes (Rph), ha a e ace-speci ic [5]. This esis ance is o en comple e, and associa - ed wi h nec osis o plan cells ha a e a acked by he pa hogen spo elings. Some o he Rph genes ha e a delayed o a he weak e ec on he pa hogen. Such Rph genes con e incomple e esis- ance, in which he ungus o ms small u edinia ha a e su ounded by chlo o ic o nec o ic plan issue (i.e. low o in e media e in ec ion ypes). The non-hype sensi i i y esis ance, also called “pa ial esis ance” [18], is no associa ed wi h plan cell nec osis. I has a ypically quan i a i e inhe i ance [13, 20]. In ield ials his esis ance is cha ac e ised by low le els o in ec ion despi e a compa ible (high) ype o in ec ion. In monocyclic es s in he g eenhouse, pa ially esis an ba ley geno ypes a e iden i ied by he long la ency pe iod o he ungus and he low in ec ion densi y as com- pa ed o he suscep ible e e ence cul i a s [15]. B eeding o esis ance o lea us in ba ley has no ecei ed op p io i y in Eu opean ba ley p o- g ammes. Howe e , selec ion agains e y suscep- ible pheno ypes occu s. In se e al ba ley b eeding p og ammes, a i icial inocula ions a e made on b eeding lines o acili a e his selec ion. Such p o- cedu es migh esul in he g adual accumula ion o quan i a i e genes o esis ance [14, 17]. He e we desc ibe he esis ance o a se o mod- e n Wes -Eu opean sp ing ba ley ge mplasm agains P. ho dei. The accessions we e es ed a se e al loca ions wi h he objec i e o assessing he le el and he ype o hei esis ance. This esea ch was complemen ed by a i ulence su ey o de e mine which Rph genes a e s ill e ec i e o he pa hogen in Eu ope, and he equency o pos- sible i ulence ac o s in he P. ho dei popula ion. His ological and mac oscopic obse a ions we e ca ied ou in a monocyclic g eenhouse es o de e mine he le el o non-hype sensi i i y esis- ance in he es ed lines. accessions con enaien des gènes d’hype sensi i i é indé e minés qui se son a é és e icaces con e ous les isola s es- és. Le ni eau de non-hype sensi i i é ou ésis ance pa ielle a é é é alué en onc ion de la pé iode la en e du champi- gnon e du pou cen age des pa ies in ec ées ap ès a o emen hâ i non associés à la néc ose des cellules égé ales. Ces pa amè es on indiqué que plusieu s accessions p ésen en un ni eau de ésis ance pa ielle plus éle é que celui de la é é ence a ec ésis ance pa ielle, ‘Vada’. Nous pou ons donc conclu e que les sélec ionneu s d’o ge on a ein des ès hau s ni eaux de ésis ance pa ielle con e P. ho dei chez le ge mplasme de l’o ge de p in emps. o ge / ouille b une / ésis ance pa ielle / i ulence / hype sensi i i é Resis ance o lea us in sp ing ba ley 771 2. Ma e ials and me hods 2.1. Mul i-loca ion ield es o esis ance 2.1.1. Plan ma e ial, loca ions and expe imen al design Twen y-nine cul i a s and b eeding lines o sp ing ba ley we e ob ained om se en b eeding companies o esea ch ins i u es in Ge many, Denma k and he Ne he lands. Almos all hose accessions we e cul i a s ha had been eleased since 1990, o b eeding lines jus abou o be eleased. They had displayed consis en ly low le - els o lea us in ec ion in he b eede s’ ield ials, and hence we e p esumed o be pa ially esis an . ‘Alexis’ was added as a suscep ible e e ence ( h ee imes), and ‘G i ’ as a mode a ely esis an e e ence ( ou imes). ‘G i ’ was used as e e - ence, since i had shown a mode a e and s able le el o esis ance du ing 12 yea s o expe imen s be ween 1981 and 1995 [29]. The se also con- ained he lines L94 (ex emely suscep ible), 116-5 and ‘Vada’ (high le el o pa ial esis ance) and 17- 5-16 (ex eme le el o pa ial esis ance, [19]). In 1998, he se was es ed a eigh loca ions in ou coun ies: Asche sleben, Hadme sleben and Langens ein (Ge many); Abed, Seje and Pajbje g (Denma k); Sandon (UK); and Wageningen ( he Ne he lands). In 1999 he se was plan ed a he same loca ions, bu ins ead o Wageningen, Landsk ona (Sweden) and Radzikow (Poland) we e included. Fou o he lines es ed in 1998 we e eplaced by new accessions in he 1999 se . This pape epo s only on he accessions ha we e included in bo h yea s’ ials. The plan ing and lea us e alua ions we e ca - ied ou acco ding o he RESI p ocedu e [7]. A each es ing si e, he se was sown in h ee o ou comple e andomised blocks. The accessions we e plan ed as mic oplo s (double ows), o as single ows. Each plan ow was 90–120 cm long wi h an in e - ow spacing o abou 25 cm. Fo each acces- sion abou 50 seeds we e a ailable pe eplica ion. A sp eade ow, consis ing o a mix u e o e y suscep ible ba ley lines o cul i a s, was sown in he alleyways, pe pendicula o he es en ies, o al e na ing wi h hem as mic oplo s. A some loca- ions, he lea us epidemics we e ini ia ed by a i- icial inocula ion o he sp eade ows, whe eas in o he loca ions, he epidemic occu ed spon a- neously. 2.1.2. E alua ion o in ec ion le els Whe e possible, he ials we e e alua ed h ee imes du ing he g owing season s a ing a he ille ing s age (g ow h s ages 21–23, [31]). The assessed pa ame e was he a e age pe cen age o lea a ea co e ed by he us u edinia. A disease se e i y scale was p o ided o he e alua o s a each loca ion in o de o educe bias be ween loca- ions and e alua o s. Da a analysis was pe o med wi h he SAS- applica ion RESI [7]. The mean disease se e i y pe accession pe loca ion pe yea was calcula ed as a mean o sco es and eplica ions. 2.2. E alua ion o ace-speci ic hype sensi i i y esis ance A he Bundesans al ü Züch ungs o schung und Kul u p lanzen, Asche sleben, Ge many, seedlings o he accessions we e inocula ed wi h six ba ley lea us isola es, ep esen ing di e en i ulence pa e ns (Tab. I). In he 1999 es he iso- la e 16-3 was eplaced by 23. A he Labo a o y o Plan B eeding in Wageningen, he seedlings we e inocula ed a he seedling s age wi h isola e 24 (Tab. I). In ec ion ypes we e eco ded o aid in he pos ula ion o Rph genes in he accessions. 2.3. Vi ulence su eys Samples o he P. ho dei popula ion we e col- lec ed in 1998 in se en Eu opean coun ies: Ge many (5 loca ions), F ance (4), he Uni ed Kingdom (3), Swi ze land (1), Aus ia (1), Denma k (1) and Belgium (1). The sampling was ca ied ou in 1998 by Felsens ein, Munich, Ge many, by use o mobile spo e aps [25]. Mos o he Ge man isola es had been p o ided by a i- ous b eeding s a ions. Spo es om single u edinia Plan Gene ics and B eeding R.E. Niks e al. 772 Table I. In ec ion ypes (on 0–4 scale)1o isola es o Puccinia ho dei ha di e en ia e be ween he a ious Rph esis- ance genes in ba ley. Cul i a Rph-gene Isola es 54-3 16-3 23 I 80 8-2 8-1 30-1+4280 24 ‘Sudan’ Rph1 0-2 2-4 4 4 4 4 4 ‘Pe u ian’ Rph2 4 3 4 4 2- 2- 4 4 Ho 679-3 Rph3 0 0 0 3 3 0 0 0 ‘Gold’ Rph4 4 4 4 4 4 4 4 4 ‘Quinn’ Rph2+Rph5 4 2-4 0 0 0 0 0 ‘Boli ia’ Rph2+Rph6 4 4 4 3 0-2 0-2 3 4 Ho 4279 Rph7 0 0 0 0 0 0 0 0 Egyp 4 Rph8 4 3 4 4 4 4 4 4 Ho 2596 Rph9 0 0 0 3 0 0 4 0 Ho 500-1 0 0 0 3 4 4 4 n. . Ho 1132 sel. 3 0 0 0 0 0 0 n. . ‘T ump ’ Rph12 0 0 0 3 0 0 4 4 ‘Lada’ Rph12 0 0 0 3 0 0 4 4 1in ec ion ypes 3 and 4 indica e i ulence; 0 o 2 indica e a i ulence. n. .: no es ed. Table II. Pe cen age o mono-u edinia-de i ed isola es o he ba ley lea us ungus (Puccinia ho dei), collec ed in 1998, ha ca y i ulence o esis ance ac o s in 15 di e en ial ba ley lines. Ba ley line Resis ance Coun y o o igin and numbe o isola es es ed gene(s) Ge many1F ance2UK3Swi ze land Aus ia Danma k Belgium 98 82 72 17 33 17 22 ‘Sudan’ Rph1 100 100 100 100 100 100 100 ‘Pe u ian’ Rph2 100 100 100 100 100 100 100 RikaxF1 Rph3 58 59 21 35 30 71 55 ‘Es a e’ Rph3 69 58 28 65 70 71 68 Ho 679-3 Rph3 75 84 40 71 85 88 77 ‘Gold’ Rph4 100 100 100 100 100 100 100 ‘Quinn’ Rph2+Rph5 20 50 83 71 21 35 50 ‘Boli ia’ Rph2+Rph6 100 100 100 100 100 100 100 ‘Cebada Capa’ Rph7 0000000 Egyp 4 Rph8 98 95 97 100 100 100 86 Ho 2596 Rph9 100 100 100 100 100 100 100 Ho 500-1 90 51 34 53 91 71 86 Ho 1132 sel. 3 8 3 12 9 0 5 ‘T ump ’ Rph12 97 100 100 100 100 100 100 ‘Lada’ Rph12 98 100 100 100 100 100 100 1Collec ed a ound Hambu g, Magdebu g, Hanno e , Leipzig and Ka ls uhe. 2Collec ed a ound Lille, Pa is, Toulouse, Bou ge. 3Collec ed a ound Ha oga e, Camb idge, Edinbu gh. Resis ance o lea us in sp ing ba ley 773 we e applied o seedling lea es o a suscep ible cul i a o p oduce mono-u edinia-de i ed isola es. A o al o 341 o such isola es we e applied o seedlings o 15 ba ley lines and cul i a s o de e - mine he i ulence equencies in he P. ho dei popula ions. Mos o hese 15 ba ley accessions (Tab. II) belong o he egula di e en ial se ies o ba ley lea us [1, 2, 26, 28]. Th ee accessions wi h Rph3 we e included. Ho 679-3 p obably only ca ies Rph3. ‘Es a e’ has been epo ed o di e om Ho 679-3 by one and Rika ×F1 by wo addi- ional esis ance genes [28]. Simila samplings and i ulence su eys had been ca ied ou in o he yea s and o he loca ions in he amewo k o he p esen s udy. The esul s o hose su eys se ed as back-up o he 1998 esul s. 2.4. E alua ion o he le el o non-hype sensi i i y esis ance The se o ba ley lines was g own in g eenhouse compa men s a he Labo a o y o Plan B eeding, Wageningen, o quan i y he le el o non-hype sen- si i i y esis ance in each accession. The se was sown in wo se ies o seedling assessmen s and in ou se ies o adul plan assessmen s. Abou 11 days a e sowing, he i s lea es we e ixed in a ho izon al posi ion and inocula ed in a se ling owe . Abou ou seedlings pe accession we e a ailable o inocula ion pe se ies. Each box ecei ed 4 mg inoculum, which amoun s o abou 200 spo es pe cm2. The p ocedu e and condi ions we e as desc ibed by Niks and Rubiales [10]. Fo he adul plan e alua ion, h ee plan s we e aised pe accession pe se ies. When he plan s had de eloped abou six o se en lea es, he uppe su ace o he uppe mos ully expanded lea (one pe plan ) was inocula ed by dus ing wi h inocu- lum. Isola e 24 o P. ho dei was used o bo h he seedling and he adul plan es s. A e i e days, h ee inocula ed lea es o each accession we e sampled o mic oscopic obse a- ions. A cen al segmen o each lea was cu , ixed in lac ophenol-e hanol, and s ained wi h U i ex o luo escence mic oscopy [9, 24]. Fo each sample, 100 in ec ion uni s we e inspec ed o hei s age o de elopmen and whe he hey we e associa ed wi h au o luo escen plan cells, indica ing plan cell nec osis. The pe cen age o ea ly abo ed in ec ion uni s no associa ed wi h plan cell nec o- sis was de e mined. Ea ly abo ed in ec ion uni s ha e no mo e han six haus o ial mo he cells [8]. Fo each accession, he in ec ion ype, on a 0–9 scale, was eco ded [6]. These obse a ions we e ca ied ou on inocula ed lea es ha had no been sampled and/o on he lea s ubs ha emained a e ha ing sampled he lea o mic oscopy. On he seedling lea es, he la ency pe iod o he us also was de e mined [11]. 3. Resul s 3.1. Resis ance le els in sp ing ba ley accessions A h ee loca ions in 1998 and i e loca ions in 1999, he le el o in ec ion was oo low o allow o a us se e i y a ing. Mo eo e , in some ins ances, only one o wo o he h ee p oposed e alua ions we e made be o e c op ma u a ion. A hose loca ions, he numbe o u edinia pe h ee ille s pe mic oplo we e coun ed (Wageningen, 1998), o a semi-quan i a i e a ing on a 1–9 o 0–10 scale was pe o med (Langens ein, Abed, bo h yea s; Landsk ona, 1999). A Seje (1999) and Radzikow (1999), he le el o in ec ion was negli- gible, and no da a we e collec ed. A i e (1998) and ou (1999) loca ions, he le el o in ec ion was su icien o collec da a ha could be consid- e ed eliable and disc imina o y among he acces- sions (Fig. 1). In bo h yea s Hadm.18091-96 was he mos esis an accession, and L94 he mos sus- cep ible. The mean disease se e i y alues di e ed sub- s an ially ac oss he loca ions, bu he anking o he accessions was simila , especially among he mos esis an and mos suscep ible accessions. Be ween he yea s he e we e only a ew s iking di e ences. ‘Co k’ was less se e ely in ec ed in 1999 han in 1998. This e ec seems mainly due o he lowe in ec ion a Hadme sleben. ‘Ria’, ‘Henni’ and Hadm.3500-96 we e ela i ely mo e Plan Gene ics and B eeding R.E. Niks e al. 774 Figu e 1. Mean disease se e i ies in 27 sp ing ba ley accessions in ec ed by Puccinia ho dei in ield ials in wo yea s and o i e and ou loca ions, espec i ely. Fo each accession he le -hand ba p esen s1998 da a, he igh -hand ba 1999 da a. LA: Landsk ona, Sweden; PF: Pajbje g, Denma k; SJ: Seje , Denma k; SAN: Sandon, UK; HAD: Hadme sleben, Ge many; AS: Asche sleben, Ge many. Resis ance o lea us in sp ing ba ley 775 se e ely in ec ed in 1999 han in 1998. Wi h ‘Ria’ and ‘Henni’, his was likely due o highe in ec ion a Hadme sleben. In con as , Hadm.3500-96 had hige in ec ion a all loca ions. The es si es di e ed in he disc imina ion be ween le els o in ec ion on he a ious accessions. In 1998, 15 accessions a Pajbje g and 19 accessions a Hadme sleben we e signi ican ly mo e esis an han he e e ence ‘G i ’. This was likely due o he ela i ely poo exp ession o esis ance in ‘G i ’ a hose loca ions. A Hadme sleben, whe e in ec ion le els we e high, ‘G i ’ was no signi ican ly mo e esis an han he suscep ible e e ence ‘Alexis’. In he o he 1998 loca ions, some accessions, including ‘Alexis’, we e signi ican ly mo e suscep ible han ‘G i ’, and none signi ican ly mo e esis an han ‘G i ’. Also in 1999 a Hadme sleben many accessions (21) we e signi ican ly mo e esis an han ‘G i ’. Again, ‘G i ’ seemed o exp ess i s esis ance poo - ly a his loca ion. Also in ha yea , ‘G i ’ was no signi ican ly di e en in lea us se e i y om he suscep ible e e ence ‘Alexis’ a Hadme sleben. In 1999, se e al o he accessions we e a he o he loca ions mo e esis an han ‘G i ’ and a ew we e mo e suscep ible han ‘G i ’. The numbe o loca ions in which he accessions had a mean disease se e i y signi ican ly di e en om e e ence ‘G i ’ is p esen ed in Table III. Also o his c i e ium line Hadm.18091-96 was in bo h yea s he mos esis an accession, and L94 he mos suscep ible. ‘Henni’ appea ed a he a iable in i s pe o mance, since in bo h yea s, i had a some loca ions a signi ican ly highe and in o he loca ions a signi ican ly lowe le el o in ec ion han ‘G i ’. Se en accessions (Hadm. 18091-96, 17-5-6, ‘Libelle’, ‘Mel an’, ‘Jacin a’, ‘Polygena’ and ‘Men o ’) we e among he en mos esis an acces- sions in bo h yea s. The mean disease se e i y (a e aged o e he loca ions) o all accessions in 1998 co ela ed e y well wi h hose in 1999 ( = 0.95, signi ican a 0.01 le el, Tab. IV). The esul s om he loca ions whe e low in ec- ion occu ed (see abo e) s ill esul ed in a simila anking o he accessions. We conclude ha he la ge majo i y o he sp ing ba ley lines we e a leas as esis an as ‘G i ’. Wi h he excep ion o some c s (e.g. ‘Henni’ and ‘Co k’), he anking o he accessions be ween loca ions and yea s we e, in gene al, no e y di - e en . 3.2. Genes o ace-speci ic hype sensi i i y esis ance Conclusions on he p esence o ace speci ic esis ance genes we e based on he seedling es s wi h he di e en ia ing isola es lis ed in Table I. The pos ula ed esis ance genes p esen in he accessions a e p esen ed in Table III. Nine acces- sions we e esis an o all isola es excep I 80, 30- 1+4280 and 24, sugges ing he p esence o Rph12. ‘Ba ke’, suscep ible only o I 80 and 30-1+4280, p obably ca ies Rph9. Six accessions we e only suscep ible o I 80, which may be explained by assuming he p esence o bo h Rph3 and Rph9/Rph12. Isola e 24, he only isola e ha dis in- guishes Rph9 om Rph12, is a i ulen o Rph3 (Tab. I). This makes i impossible o de e mine whe he he six accessions ca y Rph9 o Rph12. The eac ion pa e n o ‘Henni’ (only esis an o 54-3, no es ed agains 16-3) sugges ed he p es- ence o Rph1, and he eac ion o Libelle (only sus- cep ible o 8-2 and I 80) sugges ed he p esence o Rph3. One accession, Hadm. 3500-96, was only sus- cep ible o isola e 24, which canno be explained by any o he Rph gene (combina ions) o which he isola es di e en ia ed (Tab. I). Tha line may he e o e ca y an unknown Rph gene. Fou acces- sions we e esis an o all isola es. One o hese, ‘Hanka’, was de i ed om a pa en known o ca y Rph7, a gene e ec i e o all isola es used in his s udy (Tab. I). In he o he ou accessions his o o he Rph gene(s) may occu . Fou accessions ga e a suscep ible in ec ion ype o all isola es, and he e o e may no ca y any o he Rph-genes o which a leas one o he iso- la es ca ies a i ulence. Since all isola es possess i ulence o Rph4 and Rph8, ei he o hose genes Plan Gene ics and B eeding R.E. Niks e al. 776 Table III. Resis ance o 27 sp ing ba ley accessions o ba ley lea us , Puccinia ho dei: he numbe o loca ions in which each accession was signi ican ly less (<) o signi ican ly mo e (>) in ec ed han he e e ence ‘G i ’ in ield es s in 1998 and 1999 (numbe o loca ions), he pu a i e Rph-genes p esen in each accession, and g eenhouse expe imen s wi h isola e 24 o de e mine he le el o non-hype sensi i i y esis ance: he la ency pe iod ela i e o line L94 ( ela i e LP), and he pe cen age o ea ly abo ed in ec ion uni s no associa ed wi h nec osis (% EA–N) de e mined in seedlings and in adul plan s. The in ec ion ype (IT on a 0–9 scale) o isola e 24 is also p esen ed. Isola e 24 Accession Numbe o loca ions Pu a i e Rph gene(s) p esen 4IT10 Rela i e LP7 % EA – N6 1998119992Seedlings Seedlings8 Adul plan s9 Hadm18091-96 2< 4< Rph? 5 - 13 21 17-5-16 2< 2< -7 144 35 49 ‘Mel an’ 2< 3< Rph3+Rph9/12 3 - 23 44 ‘Libelle’ 2< 3< Rph3 1 - 17 36 ‘Jacin a’ 2< 1< Rph? 5 - 44 56 ‘Ria’ 2< 1< Rph12 7 144 45 53 ‘Polygena’ 2< 2< Rph3+Rph9/12 2 - 13 26 ‘Men o ’ 2< 2< Rph3+Rph9/12 1 - 26 23* ‘Hanka’ 2< 1< Rph751 - 12 24 ‘Vada’ 1< 2< -7 126 27 43 ‘Ba ke’ 2< 3< Rph9 2 - 6* 3 GS1568 1< 2< Rph3+Rph9/12 1 - 17 24 ‘Coope ’ 1< 2< Rph12 7 125 42 45 Hadm.3500-96 2< 0 Rphx 7 114 10 33 ‘Co niche’ 2< 1< Rph12 8 110 11 36* 116-5 1<1> 2< -8 124 16 21 ‘Henni’ 2<1> 1<1> Rhp1 8 111 28 29 ‘Fe gie’ 2< 1< Rph12 8 114 9 15 ‘Co k’ 1< 2< Rph3+Rph9/12 1 - 36 54 ‘Lisbe ’ 1<1> 0Rph12 7 111 9 7 ‘Op ic’ 0 1< Rph12 7 121 23 28 ‘Ba ok’ 1> 1> Rph12 7 127 22 44 ‘G i ’300Rph12 8 124 9 13 ‘Allio ’ 2> 0Rph? 2 - 18 12 ‘Madei a’ 2> 2> Rph12 7 105 2* 7* ‘Alexis’ 4> 3> Rph3+Rph9/12 3-916 L94 5> 4> - 9 100 3 2 1To al numbe o loca ions: 5. 2To al numbe o loca ions: 4. 3‘G i ’ was included as accession, and es ed agains h ee plo s pe eplica ion in which ‘G i ’ se ed as e e ence. 4-: no e idence o any Rph-gene; Rph?: unknown Rph gene(s) e ec i e o all di e en ia ing isola es; Rphx: unknown Rph gene(s) e ec i e o all di e en ia ing isola es excep isola e 24. 5as Rph?, bu Rph7 gene p esumed because o ances y. 6Figu es ma ked by * a e based on only one eplica ion. 7-: no measu ed because o low in ec ion ype. 8Based on wo eplica ions, h ee lea segmen s pe eplica ion, 100 in ec ion uni s pe lea segmen . 9Based on ou eplica ions, h ee lea segmen s pe eplica ion, 100 in ec ion uni s pe lea segmen . 10 Based on he 0–9 scale o McNeal e al. [6]. Fo i ulence spec um o his isola e, see Table I.