Early cytological differences between compatible and incompatible interactions of soybeans with Phytophthora megasperma f.sp. glycinea

摘要: Abstract The interaction of soybean cv. Harosoy 63 with Phytophthora megasperma f.sp. glycinea race 1 (incompatible) and 4 (compatible) the near-isogenic these races was examined by light electron microscopy in hypocotyl tissues fixed 2, 3, 5 7 h after inoculation. extent rate colonization similar both incompatible compatible interactions. Hyphae reached first layer cortex 2 third 3 h. However, there were major differences host-cell responses. In (Harosoy 63-race 1) virtually all epidermal cells at surrounding infection sites dead h, throughout a majority associated hyphae each incubation period. Penetrated almost always even when wall appositions present. There relatively few interactions although more than those 4. penetrated alive. ultrastructural evidence damage to but not Host-cell death temperature-induced susceptible response Altona 33 °C only marginally less resistance 25 °C, much greater °C. It is concluded that, whereas observations are consistent operation recognition system triggering as an immediate interactions, it unlikely that susceptibility due changes such system.