A Database for Triticeae and Avena
Ant 566 is a mutant induced from the cultivar Manker, which carries
the ant13 gene (Jende-Strid, 1988). An allele at this locus was found
to be linked to net blotch susceptibility in a cross between Ant 13-13
with the resistant cultivar Norbert (Metcalfe and Bendelow, 1981).
Therefore, we decided to determine if negative associations existed
between the gene in Ant 566 and resistance to net blotch, incited by
Phyrenophora teres Drechs., and spot blotch, incited by Cochliobolus
sativus (Ito and Kurib. in Kurib) Drechs. ex Dast., present in the
resistant line NDB112.
Material for this study was derived from the cross Ant 566/NDBI12.
Five plants were harvested from each of 15 F3 families homozygous for
the ant gene and from each of 15 families homozygous for normal
pigmentation. A total of 150 F3 derived F4 families were examined for
the two diseases in separate experiments. Seedlings were inoculated
with single spore isolates of the two organisms as described by Berglund
and Pederson (1981). The material was arranged in five sets, with each
set containing ant and normal families. Three runs of each experiment
separated at weekly intervals for net blotch, and daily intervals for
spot blotch were conducted. Six days after inoculation disease reaction
was scored based on a 0-9 scale.
Net blotch and spot blotch mean reactions (Table 1) of mutant and
normal families were similar but significantly different in the two
experiments (Table 2). Net blotch reaction was higher (3.9) for the
mutant group compared to the normal group (3.7). This observed
difference may be caused by an association of a factor determining net
blotch susceptibility with ant13. Spot blotch reaction was higher for
the normal group (4.2) than for the mutant group (3.6). This difference
may be caused by a gene for resistance linked to the ant13 allele
present in the mutant material.
Results obtained from these experiments suggest that genes having
small effect on reaction to the two diseases are weakly associated with
ant13 locus. Also, we can assume that the gene for net blotch
resistance in Norbert (Metcalfe and Bendelow, 1981) is not present in
NDBI12 or a stronger association between Ant 566 and net blotch
susceptibility would have been observed. The range in disease reactions
observed for ant selections and normal type families was very similar
for the two diseases, indicating that resistant lines can be selected
from either the ant or normal material.
Berglund, D., and V.D. Pederson. 1981. Improved technique for
screening barley lines against Cochliobolus sativus and Pyrenophora
teres. Phytopathology 71:1115. (Abstr.)
Jende-Strid, B. 1988. Coordinator's report: Anthocyanin genes. Stock
list of ant mutants kept at Carlsberg Laboratory. BGN 18:74-79.
Metcalfe, D.R., and V.M. Bendelow. 1981. Relations between barley
polyphenol content and reaction to stem rust and net blotch. In
Barley Genetics IV, Edinburgh, pp. 484-488.