Diversity and relationships of multipurpose seabuckthorn (Hippophae L.) germplasm from the Indian Himalayas as assessed by AFLP and SAMPL markers

Seabuckthorn, a non-leguminous nodule bearing dioecious shrub, is a storehouse of neutraceutical, pharmaceutical and cosmetic usage. The 348 genotypes of Hippophae rhamnoides ssp. turkestanica, H. salicifolia and H. tibetana were collected from 194 locations at 46 major sites across ~1,500 km from north-east to north-west Himalayas, harboring one of the most harsh, highly variable climatic and ecological conditions and rugged rocky terrain in the range of 3,000–5,000 m altitude. Amplified fragment length polymorphism (AFLP) and selective amplification of microsatellite polymorphic loci (SAMPL) DNA markers were utilized to assess, the genetic diversity of total spectrum of Himalayan germplasm resources and interrelationships among Hippophae taxa. A total of 151, 50, and 41 AFLP loci were detected in Hippophae rhamnoides ssp. turkestanica, H. salicifolia and H. tibetana, respectively; of these, 92.6, 30.6 and 25.1% were polymorphic. For SAMPL, the number of markers and polymorphism for these species were, respectively, 77 (77.7%), 41 (41.4%), and 23 (23.2%). Nei’s genetic diversity and Shannon’s information index values revealed that populations of H. rhamnoides ssp. turkestanica in Sumur and Raling in Ladakh and Lahaul-Spiti, respectively, were the most diverse. In H. salicifolia and H. tibetana, the populations in Changu, and Takcha and Guling in Spiti valley, were the most diverse. In H. rhamnoides ssp. turkestanica, high level of interpopulation genetic diversity with the little intra-population diversity was accompanied by very low gene flow (Nm) range, estimated by AFLP (0.571–0.943) and SAMPL (0.321–0.726) markers. In H. rhamnoides ssp. turkestanica, the genotypes collected from Uttaranchal were found to be the least diverse. The exclusive characteristics of the nuclear genome in the Uttaranchal genotypes warrant new species rank more closer to H. salicifolia rather than to H. rhamnoides ssp. turkestanica. The present results also provide explicit evidence to suggest that both H. salicifolia and H. tibetana deserve species rank.