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 Plains. Genetic relationships existing among 28 Texas bluegrass genotypes were investigated using amplified fragment length polymorphism (AFLP) and randomly amplified polymorphic DNA (RAPD). A total of 3756 AFLP markers were generated 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 rate of 73.71%. Unweighted pair-group method using an arithmetic average (UPGMA) cluster analysis using AFLP and RAPD data separated the 28 Texas bluegrass accessions into two broad groups. With a few exceptions, the females clustered with females and males with males. These results indicate that, it may be possible to discriminate between males and females using molecular markers. Principal coordinate analysis of AFLP and RAPD data also indicated two distinct groups and revealed genetic variability among and within the groups. Based on their genetic similarity indices, high correlation was observed between AFLP and RAPD markers.