RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) VARIATION AMONG NATIVE LITTLEBLUESTEM [SCHIZACHYRIUM-SCOPARIUM (MICHX.) NASH] POPULATIONS FROM SITES OF HIGH AND LOW FERTILITY IN FOREST AND GRASSLAND BIOMES

Random amplified polymorphic DNA (RAPD) markers were used to provide e stimates of the comparative genetic variation within and among four na tive populations of Schizachyrium scoparium. Genotypes were collected from high- and low-fertility sites in both New Jersey (forest biome) a nd in Oklahoma (grassland biome), USA, and propagated in the greenhous e. Four oligonucleotide primers, 10 bp in length, produced a total of 60 RAPD markers, with the minimum marker difference between any two in dividuals being 14 markers. Euclidean metric distances were calculated among all individuals, and the analysis of molecular variance (AMOVA) technique was used to apportion the total genetic variation among ind ividuals within populations, populations within fertility levels, popu lations within biomes, fertility levels, and biomes. Even though most genetic variation resided within populations, statistically significan t differences were detected between populations within each biome. Fur thermore, genetic distances between high and low fertility levels with in biomes were equal to or greater than biome distances. Therefore, in this wide-ranging and highly variable species, RAPD analysis suggests that local site differences in fertility and ecological history can p romote genetic differentiation equal to or greater than geographical d ifferentiation.