Assessment of genetic diversity in Ethiopian field pea (Pisum sativum L.) accessions with newly developed EST-SSR markers.
BACKGROUND
Field pea (Pisum sativum L.) is among the prominent crops in the world as food and feed. There are relatively few simple sequence repeat (SSR) markers developed from expressed sequence tags (ESTs) in P. sativum.


RESULTS
In the present study, 15 new EST-SSR markers were developed from publicly available ESTs. These markers have successfully amplified their target loci across seven Pisum sativum subsp. sativum accessions. Eleven (73%) of these SSRs were trinucleotide repeats, two (13%) dinucleotide and two (13%) were hexanucleotide repeats. Across-taxa transferability of these new markers was also tested on other subspecies of Pisum as well as on P. fulvum, Vicia faba and Lens culinaris. In Pisum sativum subsp. sativum, 13 of the 15 markers were polymorphic and 12 of them subsequently used for genetic diversity analysis. Forty six accessions, of which 43 were from Ethiopia, were subjected to genetic diversity analysis using these newly developed markers. All accessions were represented by 12 individuals except two (NGB103816 and 237508) that were represented by 9 and 11 individuals, respectively. A total of 37 alleles were detected across all accessions. PS10 was the most polymorphic locus with six alleles, and the average number of alleles per locus over the 12 polymorphic loci was 3.1. Several rare and private alleles were also revealed. The most distinct accession (32048) had private alleles at three loci with 100% frequency.


CONCLUSIONS
These newly developed EST-SSR primer-pairs successfully amplified expected loci in P. sativum subsp. sativum as well as in other subspecies of the genus Pisum and related genera. High levels of genetic variation were detected in field pea accessions from Ethiopia using these markers. This result implies the potential of the Ethiopian field pea gene pool for improvement of field peas in various desirable traits. In addition, these markers could be a valuable asset in resolving the inconsistency in the taxonomic status of the different subspecies of genus Pisum as well as for characterization of field pea accessions in different gene banks around the world for breeding and conservation purposes.
Department of Plant Breeding, Swedish University of Agricultural Sciences, Box 101, SE-23053, Alnarp, Sweden. Abel.Teshome@slu.se.
Abel
A
Teshome
Department of Plant Breeding, Swedish University of Agricultural Sciences, Box 101, SE-23053, Alnarp, Sweden. Tomas.Bryngelsson@slu.se.
Tomas
T
Bryngelsson
Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia. kifled35@yahoo.com.
Kifle
K
Dagne
Department of Plant Breeding, Swedish University of Agricultural Sciences, Box 101, SE-23053, Alnarp, Sweden. Mulatu.Geleta.Dida@slu.se.
Mulatu
M
Geleta
D000483:Alleles; D016000:Cluster Analysis; D005002:Ethiopia; D020224:Expressed Sequence Tags; D005787:Gene Frequency; D056426:Genetic Loci; D014644:Genetic Variation; D018895:Microsatellite Repeats; D018532:Pisum sativum / Q000235:genetics*; D011110:Polymorphism, Genetic