Pythium oligandrum ISSR electrophoretic patterns. Lane 1, BenchTop 100-bp ladder (Promega, France); lane 2, P. dissotocum LMSA 1.01.531; lane 3, P. oligandrum CBS 109981; lane 4, P. oligandrum CBS 530.74; lane 5, P. oligandrum LMSA 1.01.631; lanes 6 to 10, P. oligandrum strains collected from tomato roots at the end of the cropping season.