Genetic Variability in Phytophthora palmivora (Butl.) Using RAPD Markers

Phytophthora palmivora causes bud rot, fruit and immature nut fall in India, and causes significant coconut yield losses. Genetic variability was estimated in 70 isolates representing seven populations from the Kerala and Karnataka regions using random amplified polymorphic DNA (RAPD) markers. RAPDs generated a total of 163 markers with 15 decamer primers, of which 92% were found to be polymorphic. The number of polymorphic loci within a single population varied from 45 to 92 with estimated hetrozygosities ranging from 0.08 to 0.23. The majority of the genetic diversity was distributed within populations (68.25%) and only 31.75% were among populations. Genetic relationships estimated by the unweighted pair-group method with arithmatic averaging (UPGMA) revealed clear separation of Kerala and Karnataka populations