Book of Abstracts - Geyseco

P - Posters
in late phase of senescence caused the increase of aminoacids
content, which was the result of cessation of phloem transport.
Phenological forms of European beech differed in initial data of
senescence of the leaves as well as different periods of senescence
phases. They also had different ability of protein compound
remobilization. Early form of beech tree remobilized 74% of total
proteins, while intermediate 73% and late form remobilized
68% of all proteins. The average level of remobilization of phenological
forms of beech tree was 80% of soluble proteins and
64% of insoluble proteins.
P09-017: GENETIC DIVERSITY OF POLISH ISOLATES
OF HYMENOSCYPHUS, THE TELEOMORPH OF CHA-
LARA FRAXINEA, THE CAUSAL AGENT OF ASH DIE-
BACK
Zarek, M.* - Kraj, W.
University of Agriculture in Krakow
*Corresponding author, e-mail: emzarek@gmail.com
Random Amplified Microsatellites (RAMS) markers were used
to investigate the genetic structure and variation of Hymenoscyphus,
the teleomorph of Chalara fraxinea, which causes dieback
of Fraxinus excelsior in Europe. Ninety five isolates, obtained
from ascospores, which represent six populations from
lowland and upland parts of Poland were analyzed. 72 (89%) out
of 81 bands generated with four RAMS primers were polymorphic.
The lowland and upland groups of isolates were obtained
by using PCA analysis.
Percentage of polymorphic loci was higher for upland (87.7)
than for lowland (81.5) isolates. The genotypic diversity inferred
from Shannon’s index was higher for upland (0.422±0.028) than
for lowland (0.390±0.028) isolates. Dice a similarity coefficient,
which was the second measure of intrapopulation variation, also
showed higher genetic differentiation of upland (0.74±0.002)
than lowland (0.78±0.003) isolates. AMOVA partitioned the total
variation into 77% intrapopulation,
19% between-population and 4% between upland and lowland
isolates. This analysis and Nei genetic distance between pairs of
populations showed that differentiation among populations was
high and depended on population elevations. It appeared that the
main factor which influences the genetic variation level is climatic
conditions. As a result of greater differentiation of climatic
conditions in upland region, the genetic variability of fungus was
greater, which allows better toleration of varied external conditions.
P09-018: GENETICAL, MOLECULAR AND ECOLOGI-
CAL ANALYSES OF FLOWERING VERNALIZATION
RESPONSES IN ARABIDOPSIS THALIANA
Méndez-Vigo, B. - Ramiro, M. - Pozas, J. - Sánchez, E. -
Martínez-Zapater, J.M. - Picó, X. - Alonso-Blanco, C.
Centro Nacional de Biotecnología (CSIC)
*Corresponding author, e-mail: bmendez@cnb.csic.es
Wild genotypes of Arabidopsis thaliana collected from different
natural populations show substantial variation for the acceleration
of flowering initiation induced by long exposure to low temperatures,
i.e. for their vernalization response (Alonso-Blanco
et al., 2009). To determine the amount of quantitative variation
existing for this response we have analysed flowering time in a
collection of 183 genotypes from different populations of the
Iberian Peninsula (Picó et al., 2008), grown with 0, 1, 2 or 3 months
at 4 °C. This analysis shows that 17% of Iberian accessions
have an obligate vernalization requirement, while several genotypes
without such requirement present a stronger response than
laboratory strains. We have selected Ll-0 and Ped-0 accessions
with different extreme vernalization responses to obtain two new
populations of recombinant inbred lines (RILs) derived from
crosses with the reference strain Landsberg erecta (Ler).
To determine the genetic bases of natural variation for vernalization
response we have measured the flowering time of these two
RIL populations grown under different vernalization periods and
we have carried out QTL mapping analyses of those data. On
the other hand, to find out part of the molecular bases of this variation
we have sequenced the FRIGIDA gene of the 183 accessions
and we have carried out association analyses between FRI
polymorphism and the flowering phenotypes of this collection.
Finally, aiming to identify environmental factors that might drive
FRI genetic variation we have compared FRI polymorphisms
with geographic and climatic factors of the natural populations
of origin. References
Alonso-Blanco et al. 2009 Plant Cell 21:1877-1896
Picó et al. 2008 Genetics 180:1009-1021.
P09-019: ASSOCIATION MAPPING: EXPLORING ALLE-
LIC RESPONSES FOR COMPLEX TRAITS
Ishihara, H.* - Sulpice, R. - Pyl, E-T. - Stitt, M.
Max-Planck-Institute of Molecular Plant Physiology
*Corresponding author, e-mail: ishihara@mpimp-golm.mpg.de
A. thaliana is a suitable model for QTL mapping of a wide range
of simple or even complex traits. However, this approach is limited
by the genetic and phenotypic diversity of the two parents
comprising mapping populations. Association mapping is overcome
these limits as it makes use of the variation existing in a
large number of natural populations. However, full genome association
mapping requires a very good coverage of the genome in
a large number of accessions for the detection of associations to
complex traits. SNP data generated in the frame of the 1001 genome
project and the Arabidopsis thaliana “HapMap” project allow
such coverage, but not definite identification of the responsible
polymorphisms for an observed association. In the laboratory, we
developed a strategy to identify candidate genes involved in the
regulation of biomass and then make association mapping using
their full sequence (Sulpice et al. 2009). Briefly, by determining
other traits (metabolites, enzymes and transcripts) and analysing
their connections together and with biomass, we could point the
potential importance of two candidate genes. The two genes were
then fully sequenced by Sanger method in >90 accessions and
several associations could indeed be identified with biomass but
also to some metabolic traits. However, to validate such approach,
other genes should be tested. One of the major issues in our
previous study appeared to be the necessity of getting high quality
sequences for a large number of accessions. After selection of
31 additional genes potentially involved in the regulation of biomass,
we are now sequencing them by 454 barcode sequencing.
Based on the associations obtained, the validity of this strategy
will be discussed.
P09-020: SCREENING FOR NITROGEN USE EFFICIEN-
CY (NUE) IN HUNGARIAN POTATO CULTIVARS
Hoffmann, B.* - Hoffmann, S. - Polgár, Z.
University of Pannonia
*Corresponding author, e-mail: hoff-b@georgikon.hu
Crop production is highly dependent on the supply of exogenous
nitrogen (N) fertilizers. With increased fertilizer application rate
the risks of N loss increase rapidly. The remaining N is lost as
either surface runoff; leached nitrate in groundwater or by volatilization
to the atmosphere; microbial denitrification, all of
which pose environmental concerns. Although nitrate losses may
be reduced through improved N fertilizer management practices,
nitrate losses are still excessive under commercial production
regions. Another approach may be to reduce nitrate loss by developing
potato cultivars which utilize N more efficiently. Nitrogen
use efficiency (NUE) is defined as dry matter production per
unit N supply. Because of the critical role of N rate in achieving
economic and environmental objectives, screening for genotypes
with better NUE may reduce production costs and contamination
of the environment by maximizing fertilizer utilization.
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