Random amplified polymorphic DNA and amplified fragment length polymorphism assessment of genetic variation in Nicaraguan populations of Pinus oocarpa

Pinus oocarpa is the most widely distributed pine species of Mexico and Cen tral America. The natural populations of Nicaragua have been affected by ex tensive human activities. As a consequence, their size has been reduced, an d there is a serious threat to the development of mature woodland. Knowledg e of population structures and the genetic diversity of the species is requ ired for the design of sustainable use and conservation strategies. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers were used to assess the genetic variation among 10 populati ons from three geographical regions of Nicaragua. Both markers revealed hig h levels of diversity in these populations. G(ST) values and analyses of mo lecular variance (AMOVA) found that most variation was within populations b ut there is still a significant differentiation between populations indicat ing that the populations sampled cannot be considered a single panmictic un it. The partitions created by AMOVA also showed that there was little diffe rentiation between populations of different regions, although cluster analy ses based on RAPDs and AFLPs indicated a closer relationship among most of the populations from a same geographical region. Management of P. oocarpa i n Nicaragua should be aimed to maintain the high degree of genetic variatio n within individual populations that is still observed even in some of thes e highly degraded populations.