Assessing genetic diversity of some Anthurium andraeanum Hort. cut-flower cultivars using RAPD Markers

Randomly amplified polymorphic DNA (RAPD) markers fingerprinting were used to assess the level of genetic variations among 24 cut-flower Anthurium andraeanum Hort. cultivars. Eight decamer primersproduced a total of 98 reproducible PCR bands that were used to calculate the Nei and Li’s genetic distance (GDNL) coefficients amongst the cultivars. GDNL values ranged from 0.018 to 0.163 with an average of 0.09 (representing an average genetic similarity of 91.34%). This significantly low average genetic distance among the various cultivars indicated that genetic variation among the cultivars was low. A dendrogram, produced using unweighted pair group method using arithmetic averages (UPGMA), grouped the cultivars into four main clusters. Cultivar ‘Antartica’ was genetically distinct from all the others. ‘Midori’ and ‘Bourgogne’ together formed a cluster whereas the remaining 21 cultivars grouped into two clusters and were closely related to each other. Clusters did not relate to cultivar provenance or origin and were independent of floral colour and spathe category. Finding correlations between these morphological traits to RAPD markers would necessitate extensive primer screening. Nevertheless, RAPD markers fingerprinting allowed a rapid assessment of the level of genetic variation that would otherwise be difficult to evaluate using the limited number of morphological markers present among these closely related  anthurium cultivars

Evaluation of genetic diversity between 27 banana cultivars (Musa spp.) in Mauritius using RAPD markers

Cultivated bananas (Musa spp.) are mostly diploid or triploid cultivars with various combinations of the A and B genomes inherited from their diploid ancestors Musa acuminata Colla. and Musa balbisianaColla. respectively. Random amplified polymorphic DNA (RAPD) markers were used to establish the relatedness of 27 accessions in the Mauritian Musa germplasm. 15 decamer primers produced a total of115 reproducible amplification products, of which 96 were polymorphic. Computation of the genetic distances shows that similarities ranged from 0.3 to 1.0 with an average of 0.51. With a few exceptions,cluster analysis differentiated pure A containing cultivars from those containing at least one B genome. This paper answers long standing questions on the taxonomic placement of the cultivar ‘BananeRouge’ by providing the basis for its classification within the homogenomic A cultivars. The results presented here also contribute to narrowing the gaps in our current understanding of the migration path of bananas and the emergence of secondary centers of diversity

Adenovirus DNA Replication

Replication of the adenovirus genome is catalysed by adenovirus DNA polymerase in which the adenovirus preterminal protein acts as a protein primer. DNA polymerase and preterminal protein form a heterodimer which, in the presence of the cellular transcription factors NFI/CTFI and NFIII/Oct-1, binds to the origin of DNA replication. DNA replication is initiated by DNA polymerase mediated transfer of dCMP onto preterminal protein. Further DNA synthesis is catalysed by DNA polymerase in a strand displacement mechanism which also requires adenovirus DNA binding protein. Here, we discuss the role of individual proteins in this process as revealed by biochemical analysis, mutagenesis and molecular modelling.</p