Isolation and characterization of microsatellite markers and analysis of genetic variability in Curculigo latifolia Dryand

Abstract

Curculin, a sweet protein found in Curculigo latifolia fruit has great potential for the pharmaceutical industry. This protein interestingly has been found to have both sweet taste and taste-modifying capacities comparable with other natural sweeteners. According to our knowledge this is the first reported case on the isolation of microsatellite loci in this genus. Hence, the current development of microsatellite markers for C. latifolia will facilitate future population genetic studies and breeding programs for this valuable plant. In this study 11 microsatellite markers were developed using 3' and 5' ISSR markers. The primers were tested on 27 accessions from all states of Peninsular Malaysia. The number of alleles per locus ranged from three to seven, with allele size ranging from 141 to 306 bp. The observed and expected heterozygosity ranged between 0.00-0.65 and 0.38-0.79, respectively. The polymorphic information content ranged from 0.35 to 0.74 and the Shannon's information index ranged from 0.82 to 1.57. These developed polymorphic microsatellites were used for constructing a dendrogram by unweighted pair group method with arithmetic mean cluster analysis using the Dice's similarity coefficient. Accessions association according to their geographical origin was observed. Based on characteristics of isolated microsatellites for C. latifolia accessions all genotype can be distinguished using these 11 microsatellite markers. These polymorphic markers could also be applied to studies on uniformity determination and somaclonal variation of tissue culture plantlets, varieties identification, genetic diversity, analysis of phylogenetic relationship, genetic linkage maps and quantitative trait loci in C. latifolia.

Fig. 1

DIVA-GIS mapping of collection sites of C. latifolia from Peninsular Malaysia

Fig. 2

The genetic profiles of 12 accessions of C. latifolia using a primer Curla13 and b Curla 33 (M: 50 bp DNA ladder (fermentas); 1–12: Accessions of C. latifolia)

Fig. 3

Dendrogram based on Dice’s similarity coefficient indicating relationships among accessions of C. latifolia

Fig. 4

The gap curve indicated number of clusters revealed

Fig. 5

Two-dimensional plot of principle components of SSR marker data among C. latifolia accessions (Dim-1, Dim-2: the two axes represent the first two principle components; labels in the graph show the collection site of C. latifolia)