This study was conducted to search for new resistant sources to oat
leaf rust as well as to characterize the macroscopic components of
resistance to crown rust under controlled conditions. One hundred twenty
different accessions of oats obtained from the National Small Grains
Collection, Idaho (NSGC), USA, in addition to a local susceptible wild
accession were used in this study during the growing season of 2008-
2009. Disease severity (DS) was calculated three times during the
growing season at two week intervals. DS values were used to calculate
Area under Disease Progress Curve (AUDPC). The results of this study
revealed that the local susceptible (control) accession had 48% DS
(100% AUDPC) of leaf rust, and DS for the tested accessions ranged
from very high to very low, and the distribution was markedly shifted
towards low DS. 50% of the collection showed AUDPC < 50%, while
thirteen cultivars. (10.8% of the collection) with AUDPC ≤ 20%, were
selected to study their reaction to artificial inoculation with uredio spores
of Puccinia coronata at seedling stage. All the tested accessions showed
significantly higher relative latency period (RLP) and lower relative
infection frequency (RIF) in comparison to the susceptible control. These
resistant cultivars were planted in the field to produce grains for further
studies.
Journal
Title
An-Najah University Journal for Research (Natural Sciences), 27 (1)