Proceedings of the XLVII Italian
Society of Agricultural Genetics - SIGA Annual Congress
Verona,
Italy - 24/27 September, 2003
ISBN 88-900622-4-X
Poster
Abstract - 2.60
AFLP and ISSR markers
utilized in the assessment of genetic variation in Italian Artichoke
N.A. Rey Muñoz**, M.A. Pagnotta*, M.T.
Cardarelli**, M. Tucci***, F. Saccardo**
*) Department of
Agrobiology and Agrochemistry, Tuscia
University, Via S.C. de Lellis, 01100 Viterbo, Italy
**) Department of
Crop Production, Tuscia
University, Via S.C. de Lellis, 01100 Viterbo, Italy
***) CNR
-Institute of Plant Genetics - section Portici, Via Università 133, 80055 Portici (Na), Italy
AFLP, ISSR, landraces, Cynara
cardunculus, germplasm
Thirty
genotypes of Artichoke landraces of “Romanesco” type have been
collected from each of three farms located in Latina province (south of Rome),
and thirty genotype from three farmers located in Salerno province in order to
assess the genetic variation existing between and within each population. Two
different kind of molecular markers, AFLPs and ISSRs, have been used. Fifty
bands have been scored for primer combination MseAC-PstCT, 93 bands for primer
combination MseTT-PstCA, and 48 for primer combination MseGC-PstAC, while 44
bands have been scored for primer 841 and 7 bands for primer 856. A total of
191 bands have been considered for AFLPs and 51 for ISSRs markers.
The results
underlying the presence of a large amount of variation within population (in
this case was considered a population constituted by the plants collected from
the same farm), ranging from 73% to 85% of the total variation, in relation
with the kind of marker used; the differences between plants from different
farm, as a consequence, account for only 27 to 15% of the total variation. A
similar distribution of the total variation within and between populations has
been found by other authors utilizing RAPDs (Lanteri et al. 2001). The
polymorphism, utilizing a polymorphism criteria of 95%, was about 77%. This is
on averaged higher than the polymorphism found, utilizing RAPDs markers, by
Lanteri et al. (2001) on artichoke from Sardinia and by Sonnante et al. (2002)
on 32 artichoke cultivars. It is interesting to note that the polymorphism is
the different populations is not consistent if AFLPs markers or ISSRs markers
were used. Probably, the two kinds of markers used explore different genome
regions with different similarity and/or differences between genotypes. The
expected heterozygosity (He) could range from 0 to 0.5 and gives an indication
if a polymorphic locus has an about equal presence of both alleles (i.e. He
close to 0.5) or has an allele very common and the other very rare (i.e. He
close to 0). In present study the He indicates that generally the high
polymorphism reviled is determined by locus with a good presence of both
alleles, hence the variability present within the farmers is definitively high.
The Nei genetic
distances between the studied populations are not very high, since there is a
high variation existing within population. But, again, the results are lightly
different if different markers are considered in the analysis computation.
The present study
demonstrates the existence of great variation within farms which still utilized
their own landraces. Hence there is material to be conserved; but, the
difficulties to found farm that utilize landraces underlay the necessity to
conserve the artichoke germplasm and the risk caused by the utilization of a
single clone on a huge number of farmers.
The work has been
sponsored by CNR Scrigno project.
The authors would
like to thank Linda Mondini for her help during some phases of the analysis.