The genetics ofPhytophthora infestans: Segregation of allozyme markers in F2 and backcross progeny and the inheritance of virulence against potato resistance genesR2 andR4 in F1 progeny

摘要: Abstract The purpose of this work was to investigate the inheritance allozymes and virulence in Phytophthora infestans . For two previously known allozyme systems (glucose phosphate isomerase peptidase) we discovered new alleles, Gpil (98) Pepl ( 83 96 ). We also determined that a uncharacterized enzyme system, mannose isomerase, had at least loci four electromorphs (93, 100, 105, 111) whose allelic relationships are not yet elucidated. observed normal segregations F1 progeny, but there were some unexpected backcrosses sibcrosses. One backcross produced predominantly heterozygous progeny for both , with expected classes homozygotes virtually absent. An excess heterozygotes another backcross, sibcrosses deficiencies homozygous classes. In virulence/ avirulence against potato resistance geneR2 segregated 1:1 ratio (P = 0.3), while segregation virulence/avirulence toR4 departed somewhat from 0.07). These results support gene-for-gene hypothesis P. suggest againstR2 is controlled single locus, againstR4 may be one or loci.