Variation among Ethiopian isolates of sclerotium cepivorum determined using morphological characteristics and random amplified DNA data.
2007
Tamire Zewde;Chemeda Fininsa;Sakhuja,P.K.;Seid Ahmed;Yuen,Jonathan;Stenlid,J(Researcher;Correspondence)
Morphological and culutural and genetic diversity in sclerotiumcepivorum berk.Population in North shewa highlands and Debre Zeit was investigated.A total of 100 isolates were collected for morphological studies.Measurements of cultural and growth paranmeters like colony diameter, days to production of sclerotia, number of sclerotia, and size of sclerotia among the isolates for the variables analysed. the genetic relationships among 47 isolates of s. cepivorum were investigated using the random amplified polymorphic DNA (RAPD) method with M13 primers. The analysis indicated that genetic diversity existed among the isolates. At species level,Nei's gene diversity (h) was 0.3474 and Shannon's index of diversity (I) was 0.5184. At population level, the percentage of polymorphic bands (PPB), the average number of alleles (na), and the number of effective alleles (ne) of the populations were different. The population diversity for isolates collected from Angolela and Asagirt was the highest (PPB=, 100, h= 0.354, I=0.5282). The unweighted pair-group mean analysis (UPGMA) cluster analysis showed that the isolates from different districts grouped in different culusters.The isolates from Angolela and Asagirt and Tarmaber were grouped into close clusters. The isolates from Deber Zeit were highly distant from North Shewa isolates. Analysis of molecular variance (AMOVA) revealed that the percentage of variance attributable to variations amoang and within the popuolations was 0.11% and 99.8%, respectively. The coefficient of gene differentiation (Gst) in the total population calculated by the population genetic, analysis was 0.1128, which indicated that the genetic variation among populations was 11.28%. The gene flow (nm) was 3.9334, which indicated that the gene permutations and interaction among populations was relatively high.
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