Genetic relatedness (diversity) and cultivar identification by randomly amplified polymorphic DNA (RAPD) markers in teasle gourd (Momordica dioica Roxb.)

Genetic relationship and variation of 29 accessions of teasle gourd (Momordica dioica Roxb.) and 1 accession of Momordica cochinchinensis Spreng. (wild relatives of teasle gourd) were examined by RAPD analysis using 44 dodecamer oligonucleotide primers. A total of 496 fragments were produced by 44 primers of which 95% bands were polymorphic. Using presence or absence of specific RAPD markers or combination of primers, 23 out of 30 accessions were identified. The genetic relatedness or genetic distance based on Nei and Li's genetic similarity varied from 0.86 to 0.65 with an average of 0.74 among 29 M. dioica accessions (when M. cochinchinensis excluded). In the phenetic dendrogram developed from cluster analysis using UPGMA method, M. cochinchinensis was out grouped as single accession, while others showing relatively weak grouping formed four groups. Clustering pattern did not demonstrate any relationship between geographical origin and genetic diversity. A DNA extraction method has been standardized. This is the first report of using RAPD techniques in teasle gourd. It was concluded that RAPD analysis is a useful tool for genotypic identification and estimation of genetic similarity in teasle gourd.