Development and Characterization of Genic SSR Markers from Indian Mulberry Transcriptome and Their Transferability to Related Species of <i>Moraceae</i>

<div><p>Improving mulberry leaf production with enhanced leaf quality holds the key to sustain the ever increasing demand for silk. Adoption of modern genomic approaches for crop improvement is severely constrained by the lack of sufficient molecular markers in mulberry. Here, we report development and validation of 206 EST derived SSR markers using transcriptome data generated from leaf tissue of a drought tolerant mulberry genotype, Dudia white. Analysis of transcriptome data containing 10169 EST sequences, revealed 1469 sequences with microsatellite repeat motifs. We designed a total of 264 primers to the most appropriate repeat regions, of which 206 were locus specific. These markers were validated with 25 diverse mulberry accessions and their transferability to closely related species belonging to family <i>Moraceae</i> was examined. Of these markers, 189 revealed polymorphism with up to 8 allelic forms across mulberry species, genotypes and varieties with a mean of 3.5 alleles per locus. The markers also revealed higher polymorphic information content of 0.824 among the accessions. These markers effectively segregated the species and genotypes and hence, can be used for both diversity analysis and in breeding applications. Around 40% of these markers were transferable to other closely related species. Along with the other genic and genomic markers, we report a set of over 750 co-dominant markers. Using these markers we constructed the first genetic linkage map of mulberry exclusively with co-dominant markers.</p></div

Genetic diversity and polymorphic information revealed by markers developed for mulberry and other closely related species.

<p>Genetic diversity and polymorphic information revealed by markers developed for mulberry and other closely related species.</p

Classification of microsatellite motifs and their frequency among the mulberry EST sequences.

<p>Classification of microsatellite motifs and their frequency among the mulberry EST sequences.</p

Transferability and distribution pattern of mulberry EST-SSR markers in closely related species belonging to <i>Moraceae</i>.

<p>Transferability and distribution pattern of mulberry EST-SSR markers in closely related species belonging to <i>Moraceae</i>.</p

List of mulberry germplasm accessions and species along with other closely related species used for validating the EST-SSR markers developed in mulberry.

<p>List of mulberry germplasm accessions and species along with other closely related species used for validating the EST-SSR markers developed in mulberry.</p

Validation of genic SSR markers in diverse mulberry accessions.

<p>Validation of genic SSR markers in diverse mulberry accessions.</p

Characterization of EST library for identification of microsatellite motifs.

<p>Characterization of EST library for identification of microsatellite motifs.</p

Diversity of the repeat motifs among the microsatellite harboring EST sequences.

<p>Diversity of the repeat motifs among the microsatellite harboring EST sequences.</p

Functional relevance of mulberry EST sequences annotated using NCBI database.

<p>Functional relevance of mulberry EST sequences annotated using NCBI database.</p