Abstract
Soybean develops a sponge-like tissue, called as secondary aerenchyma, from the phellogen under flooding condition. Phellogen also develops the perierm which prevent the invation of pathogen. Which tissue will be developped when the soybean is invaded by pathogens under flooding conditions? We obserbed the hypocotyl inoculated with Cylindrocladium parasiticum as the pathogen of soybean black root rot under flooding.
The hyphae easily reached to the inner secondary aerenchyma through the extra large space. Phellogen developed periderm against to the invasion, and the periderm prevented the invasion of hyphae into the inner tissues. This is reasonable, but the root system would become the hypoxia in the future. We will report the developmental stage of secondary aerenchyma for preventing the pathogen.
