Annual Progress Report on Malting Barley Research March, 2002

39
OTHER BARLEY DISEASES
In 2001, resistance screening was conducted for six diseases in addition to FHB (kernel
discoloration, spot blotch, net blotch, septoria speckled leaf blotch, powdery mildew, and
loose smut). The number of populations and size of population varied depending on the
disease. Screening was done in the field or in glasshouse for the six diseases. Screening
of kernel discoloration, net blotch, powdery mildew, and loose smut was done in
collaboration with Dr. Ruth Dill-Macky. Screening for resistance to spot blotch and
septoria speckled leaf blotch was done in collaboration with Dr. Brian Steffenson and Dr.
Toubia-Rahme, respectively.
QUALITY EVALUATIONS
Approximately several hundred samples from lines in advanced stages of testing have
been submitted to the Cereal Crops Research Unit for quality evaluation. Data received
in December was of good quality and was used to select among crosses made in our fall
greenhouse. In addition, this data allowed us to identify entries for 2002 advanced yield
trials. Quality data from F5 head rows is expected soon and will be used to select lines
for this years preliminary yield trial entries.
OTHER STUDIES
1. Assessing Genetic Diversity of FHB resistant sources Graduate student Bill
Wingbermuehle is characterizing seven sources of resistance from unadapted two-rowed
barley with a set of 60 SSR markers and conducting cluster analyses. Three of the seven
sources of FHB resistance (CIho4196, PFC88209, and HOR211) were different from
previously characterized sources based on genetic distance estimates. Technician Kelley
Belina is conducting a similar analysis on six-rowed spring lines from the world
collection that posses some resistance to FHB. These data sets, as well as the set of data
characterizing the Minnesota elite breeding germplasm (described below), are being
combined to help develop strategies for retaining desirable genes assembled over 50
years of plant breeding and introgressing new genes for disease resistance.
2. Evolution of SSR Allelic Diversity in the Development of Elite Minnesota Barley
Germplasm. Graduate student Federico Condon is testing the effect of breeding within a
narrow germplasm on genetic diversity. He has examined coancestry coefficients and
SSR allelic diversity in a set of 58 variety candidates developed over a 40+ year period in
the University of Minnesota breeding program, 26 of the 31 direct ancestors to the
breeding program, and 9 of the founders of the Midwestern six row barley germplasm.
Using 30 SSR's distributed across seven chromosomes, the average number of alleles per
locus was 6.8 in the direct ancestors. The average number of alleles in the varieties
candidates developed in four consecutive decades from 1958 to the present was 3.7, 2.6,
2.0 and 2.6 respectively. The rate of change in the number of alleles was not constant
across the genome. For example, Bmag613, in chromosome 7 changed from 6 alleles to 1
and Bmag872 on chromosome 5 changed from 5 to 4. These changes in allelic diversity
will be examined with respects to traits under selection in the breeding program and map
positions of known genes/QTL's conditioning those traits.