Molecular characterization of coconut ( Cocos nucifera L.) varieties in Vietnam using sequence-related amplified polymorphism (SRAP) markers

Being predominantly cultivated in the tropics, coconut ( Cocos nucifera L.) is one of the most important palm crops in the world. Even though it provides a significant source of income for smallholder farmers in many developing countries including Vietnam, its genetic diversity is yet to be well understood. In this study, genetic diversity and genetic relationships amongst 19 coconut varieties collected from Mekong Delta were analyzed and mapped using a set of 30 sequence-related amplified plymorphism (SRAP) markers. Results showed that, out of 99 amplified bands, 82 bands (ranging from 150 to 2500 bp in size) were found to be polymorphic. On average, each primer exhibited 3.71 reproducible polymorphic bands per reaction. The values of polymorphism information content (PIC) ranged from 0.08 to 0.50 and the resolving power (Rp) were between 0.32 and 1.92. The average values of Shannon’s diversity index (I) and heterozygosity (He) were 0.21 and 0.15 respectively. Inter-varietal differentiation accounted for 42% of total genetic variation. The Unweighted Pair Group Method with Arithmetic mean (UPGMA ) clustering classified the 19 coconut varieties into two clades with three major clusters. The present study provided valuable information on genetic diversity of coconut cultivation, thereby being of great use for the selection and development of coconut planting materials in Vietnam.