Genetic diversity among Texas bluegrass genotypes (Poa arachnifera Torr.) revealed by AFLP and RAPD markers

Texas bluegrass Poa arachnifera Torr., is a vigorous sod-forming perennial, dioecious grass, tolerant to heat. It is native to the Southern Great Plai ns. Genetic relationships existing among 28 Texas bluegrass genotypes were investigated using amplified fragment length polymorphism (AFLP) and random ly amplified polymorphic DNA (RAPD). A total of 3756 AFLP markers were gene rated on the 28 genotypes of Texas bluegrass. A wide range of polymorphism (23.08-85.33%) was observed among primer combinations with a mean of 64.11% . Among 441 RAPDs assayed, 335 were poly morphic with a mean polymorphic ra te of 73.71%. Unweighted pair-group method using an arithmetic average (UPG MA) cluster analysis using AFLP and RAPD data separated the 28 Texas bluegr ass accessions into two broad groups. With a few exceptions, the females cl ustered with females and males with males. These results indicate that, it may be possible to discriminate between males and females using molecular m arkers. Principal coordinate analysis of AFLP and RAPD data also indicated two distinct groups and revealed genetic variability among and within the g roups. Based on their genetic similarity indices, high correlation was obse rved between AFLP and RAPD markers.