Analysis of Genetic Diversity of Citrus Genotypes Collected in Ha Giang by RAPD and ISSR Markers

Abstract

      Oranges grown in Ha Giang are one of the most common citrus products in northern Viet Nam. However, vegetative propagation and selection for adaptation to various growing environments led to deviation from original genotype. Assessing genetic diversity of indigenous citrus may contribute to the collection, classification, evaluation and conservation as well as provide genetic information among citrus germplasm, which could be used for the breeding program. RAPD and ISSR analysis combined with the construction of phylogenetic tree revealed the genetic relationship among researched citruses. The results showed that 25 RAPD and 5 ISSR primers generated polymorphic patterns of PCR products (100%), however, the numbers of polymorphic bands detected on each genotype were significant in range. A total of 2157 DNA bands were found with an average of 1.80 DNA bands per genotype. RAPD markers (OPAW19 and OPAE15) and ISSR markers ( T1 and T5) yielded highest polymorphism, with 4.48, 4.23 and 3.25, 3.45 bands per genotype, respectively. The results also indicated that the similarity coefficient of 39 samples ranged from 0.33 to 0.98 and 5 genetic groups were obtained.