GENETIC MAPPING:

The genetic variability of this species is normally high at the center of origin, and information on such variability is essential for A. sellowiana conservation, breeding and commercial production. In general, specific phenotypes of discreet variation are used as morphological markers. However, a limited number of morphological markers have been identified for this species, which are frequently affected by dominance and epistatic gene interactions, environmental effects and pleiotropy. To overcome such problems, molecular markers can be used to help genetic characterization and breeding (Dos santos et al, 2007).

Among the classes of molecular markers available to identify variation at DNA level, the microsatellites, or simple sequence repeats (SSRs), are considered ideal markers for genetic studies because they combine several suitable features: (i) co-dominance; (ii) multiallelism; (iii) high polymorphism, allowing precise discrimination even of closely related individuals; (iv) abundance and uniform dispersion in plant genomes; and (v) the possibility of efficient analysis by a rapid and simple polymerase chain reaction (PCR) assay. In addition, for the amplification of microsatellite loci, a knowledge of their DNA sequence is required, and this is an expensive and time consuming process. However, the approach of using enriched libraries with repetitive sequences has been very successful in developing SSRs at a reasonable cost (Dos santos et al, 2007). 

The ability to use the same microsatellite primers in different plant species, called transferability, depends on the extent of sequence conservation in the primer sites flanking the microsatellite loci and the stability of those sequences during evolution. It has been shown that closely related species are more likely to share microsatellite priming sites than more distantly related ones, but it is possible to transfer functional microsatellite primers even from more distantly related species (Dos santos et al, 2007).

Because there are no microsatellites available for A. sellowiana, the Eucalyptus spp. primers of microsatellite loci can be used as an alternative to find similar regions on the A. sellowiana genome, since they belong to the same family (Dos santos et al, 2007).

(Dos santos et al, 2007).

(Dos santos et al, 2007).

 (Dos santos et al, 2007).

BIBLIOGRAPHY:

1. DOS SANTOS, K.; WELTER, L.; DANTAS, A.; GUERRA, M.; DUCROQUET, J.; NODARI, R. Transference of microsatellite markers from Eucalyptus spp to Acca sellowiana and the successful use of this technique in genetic characterization. Genet. Mol. Biol.  [serial on the Internet]. 2007  [cited  2011  May  10] ;  30(1): 73-79. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100014&lng=en.  doi: 10.1590/S1415-47572007000100014.