Cross genera transferability of microsatellite markers from other members of family Bignoniaceae to Tecomella undulata (Sm.) Seem

Abstract

Transferability of SSR markers from related species/genera is a rapid and cost-effective method to enhance genomic database of genetically neglected crops. Monotypic genus Tecomella undulata, a pharmacologically important endangered timber tree, found in hyper arid regions is one such genetic resource limited species, wherein neither SSR identification nor cross transferability studies have been initiated. Transferability of 69 cross-genera SSR primers selected from other members of family bignoniaceae (Incarvillea sinensis, I. mairei, Jacaranda copaia, Tabebuia aurea and Arrabidaea chica) showed 40.58% (28 primers) transferability amplifying 1–10 amplicons ranging in the size from 80to 600 bp in 24 accessions of T. undulata. Per cent marker transferability varied from 66.67% (A. chica) to 38.89% (J. copaia) among the genera tested while no transferable markers could be identified from I. sinensis. Transferability of simple di-/tri-nucleotide repeat (34.2–37.5%) and complex nucleotide sequence (60.0%) based SSR motifs were higher as compared to penta-/hexa-nucleotide based repeat motifs. Within the 28 transferable markers, 26 (92.86%) were polymorphic while 2 (7.14%) were monomorphic. Average number of alleles per primer was 5.39 while average polymorphic alleles per locus were 5.11. The PIC values of SSR markers ranged from 0.23 to 0.85 with an average of 0.59. Efficiency of the identified cross species SSR markers was tested for diversity analysis using a set of 24 trees (8 each of yellow, orange and red flower colour morphotypes). The 24 samples clustered into six groups with similarity coefficient ranging from 0.29 to 0.67, while six accessions formed distinct out groups. Distribution of accessions in the SSR dendrogram showed no correlation with flower colour. More diversity (99%) was observed within populations compared to that existing between populations (1%). The present study can enrich the genomic background of T. undulata by identifying suitable polymorphic markers from confamiliar species that can be applied for genetic diversity studies, mapping of QTLs and cultivar identification as well.