NEW RESISTANCE GENES TO THE BROWN LEAF RUST, <i>PUCCINIA HORDEI</i> IN WILD BARLEY FROM ISRAEL NEW RESISTANCE GENES TO THE BROWN LEAF RUST, PUCCINIA HORDEI
IN WILD BARLEY FROM ISRAEL

J. Manisterskiš and Y. Aniksterš ˛
šInstitute for Cereal Crops Improvement and ˛Department of Botany. The George
S. Wise Faculty of LIfe Sciences, Tel Aviv University 69978, Ramat Aviv, Israel

Brown leaf rust of barley caused by Puccinia hordei Otth, accomplishes its life cycle in Israel on the widespread natural mixed populations of its main host - Hordeum spontaneum and the alternate host - Ornithogalum (seven species).

The coevolution of the fungus with its two hosts, together with the annual occurrence of the sexual stage of the fungus, has resulted in an extraordinary richness of fungal races on the one hand and, as a mirror image, a whole range of resistant Hordeum plants on the other.

In 1978 we found fungal isolates that are virulent on all known genes for resistance including Rph7 (1). Later, more isolates virulent on plants carrying Rph7 were found in Morroco (2), and recently also in the U.S.A. (3). Screening Israeli populations of H. spontaneum, we have identified five accessions showing resistance to two Israeli isolates T-40 and T-45, and two isolates of Moroccan origin, #7060 and #7012, virulent on Rph7 plants as well as on plants carrying the other known resistant genes tested (Table 1).

The F1 generations of crosses of two of the resistant H. spontaneum accessions with the Rph7 carrying cultivar Cebada Capa, were resistant to the 4 virulent isolates. Preliminary results of F2 segregations point to the existence of two genes for resistance.

These results brought us to the conclusion that we have two new genes for resistance denoted Rph13 and Rph14 in these recently screened H. spontaneum populations.

These dominant resistant genes, carried by H. spontaneum accessions: H.S.586; H.S.694; H.S.695; H.S.780 and H.S.1161-2. confers resistance to the isolates which overcome on all other known genes for resistance to P. hordei.

Continuation of the research will ascertain whether these accessions carry additional genes for resistance to P. hordei.

Table 1. Reactions of a set of cultivated barley differentials and a group of H. spontaneum accessions to inoculation with four isolates of P. hordei 


                                                 Isolates            
                                     _______________________________
Serial  Cultivars(1-15)  Resistance  Moroccan origin  Israeli origin 
No.     and wild          genes        7060     7012    T-40    T-45  
       accesssions(16-21)                                           
____________________________________________________________________
1        Sudan            Rph           S*       S       S       S    
2        Peruvian         Rph2          S        S       S       S    
3        Ricardo          Rph2+         S        S       S       S    
4        Reka #1          Rph2+         S        S       S       S    
5        Quinn            Rph2+Rph5     S        S       S       S    
6        Bolivia          Rph2+Rph6     S        S       S       S    
7        Estate           Rph3          S        S       S       S    
8        Aim              Rph3          S        S       S       S    
9        Gold             Rph4          S        S       S       S    
10       Magnif           Rph5          S        S       S       S    
11       Cebada Capa      Rph7          S        S       S       S    
12       Egypt #4         Rph8          S        S       S       S    
13       CI-1243          Rph9          S        S       S       S    
14       Vada                           S        S       S       S    
15       Nigrate                        S        S       S       S    
16       H.S.586                        R        R       S       R    
17       H.S.694                        R        R       S       R    
18       H.S.695                        R        R       S       R    
19       H.S.780                        R        R       S       R    
20       H.S.1161-2                     R        R       S       R    
21       H.S.1184                       S        S       S       S
S - susceptible
R - resistant

References

  1. Golan, T., Anikster, Y., Moseman, J. G. and Wahl, I. 1978. A new virulent strain of Puccinia hordei. Euphytica 27:185-189.
  2. Parlevliet, J. E., van der Beek, J. G. and Pieters, R. 1981. Presence in Morocco of brown rust, Puccinia hordei, with a wide range of virulence to barley. Cereal Rusts Bull. 9:3-8.
  3. Steffenson, B. J. and Jin, Y. 1993. Pathotypes of Puccinia hordei with virulence for the barley leaf rust resistance gene Rph7 in the United States. Plant Disease 77: 867-869.