Histological responses in Hordeum chilense to brown and yellow rust fungi

Abstract

The histological reaction of 16 Hordeum chilense accessions to Puccinia recondila, P. hordei and P striiformis was investigated. It is not possible to generalize about the reaction of H. chilense to these rust fungi. Several lines showed a susceptible infection type to a brown rust harvested on H. juhatum. One of these lines had an intermediate infection type to the wheat brown rust fungus. The H. chilense reaction to the yellow rust fungi ranged from susceptible to resistant. The lines differed in their response to the rust fungi, as expressed by the level of early abortion of sporelings, and the frequency of plant‐cell necrosis associated with the infection sites. All the lines caused complete early abortion associated with infrequent necrosis of the rye brown rust fungus. The responses were to some extent rust non‐specific. The differences in response between the lines may reflect differences in general defence mechanisms.