Identification and genetic relationship based on ISSR analysis in a germplasm collection of sea buckthorn (Hippophae L.) from China and other countries

Sea buckthorn (Hippophae L.) is a woody, outcrossing dioecious pioneer plant, being widely planted as a new berry crop with rich nutritional and medicinal compounds, as well as a means of prevention of soil erosion. Inter simple sequence repeat (ISSR) markers were generated in 219 plants of 40 cultivars from China and other countries, representing two species of Hippophae salicifolia and Hippophae rhamnoides that includes two subspecies (ssp. mongolica and ssp. rhamnoides) and intraspecific hybrids between ssp. mongolica and ssp. sinensis. Fifteen selected ISSR primers generated 385 bands with an average of 25.6 bands per primer. Thirty hundred and eighty-five bands were used to generate a Dice's coefficient matrix of pairwise comparisons between individual ISSR profiles. Cluster analysis based on this matrix showed clustering of plants into groups which was in good agreement with their taxonomic classification. The results also revealed the presence of different cultivars with the same name, identical cultivars but with a different name and the genetic relationship of cultivars with unknown parentage to those with known parentage. Our data will be helpful in collection and conservation of sea buckthorn germplasm and potential hybrid strategy for breeding.