Abundance and polymorphism of microsatellite markers in the tea tree (Melaleuca alternifolia, Myrtaceae)

The sequencing of 831 clones from an enriched microsatellite library of Mel aleuca alternifolia (Myrtaceae) yielded 715 inserts containing repeat motif s. The majority of these (98%) were dinucleotide repeats or trinucleotide r epeats averaging 22 and 8 repeat motifs respectively. The AG/GA motif was t he most common, accounting for 43% of all microsatellites. From a total of 139 primer pairs designed, 102 produced markers within the expected size ra nge. The majority of these (93) were polymorphic. Primer pairs were tested on five selected M. alternifolia genotypes. Loci based on dinucleotide repe ats detected on average a greater number of alleles (4.2) than those based on trinucleotide repeats (2.9). The loci described will provide a large poo l of polymorphisms useful for population studies, genetic mapping, and poss ibly application in other Myrtaceae.