Resistance to Phialophora gregata is expressed in the stems of resistant soybeans

Resistance to Phialophora gregata is expressed in the stems of resistant soybeans

2003

A:PS

Growth chamber experiments were conducted to determine if resistance to Phialophora gregata, the causal agent of brown stem rot (BSR) of soyabean, is expressed in the stems of resistant soyabean genotypes. Upon introduction of the pathogen into the base of stems of 2-week-old seedlings, the fungus advanced with the growing tips of susceptible genotypes but lagged behind in the resistant genotypes. Five weeks after the introduction of the pathogen, both the mean percent stem length colonized by P. gregata and the mean percentage of symptomatic trifoliate leaflets were significantly less for the resistant than for the susceptible genotypes. These results indicate that resistance can be expressed in the stems of resistant soyabean plants and suggest that stem inoculation methods may be useful for assessing resistance to P. gregata. Also, in our experiments, internal stem discoloration was not as useful as colonization and foliar symptoms in discriminating the resistant from the susceptible genotypes.

v.87(8):970-976, PLANT DISEASE

Research > Published Articles