| random amplified polymorphic dna analysis of heterodera cruciferae and h. schachtii populations. | heterodera schachtii and h. cruciferae are sympatric in california and frequently occur in the same field upon the same host. we have investigated the use of polymerase chain reaction (pcr) amplification of nematode dna sequences to differentiate h. schachtii and h. cruciferae and to assess genetic variability within each species. single, random oligodeoxyribonucleotide primers were used to generate pcr-amplified fragments, termed rapd (random amplified polymorphic dna) markers, from genomic dna ... | 1992 | 19283007 |