Use of reciprocal grafting to study brown stem rot resistance in soybean

Resistance to brown stem rot of soybean has been identified and utilized in cultivar development and germ plasm enhancement. However, little is known about the nature of resistance to this disease. In an attempt to better und erstand the resistance mechanism by locating the tissue or tissues responsi ble for resistance, reciprocal grafts were made between brown stem rot-resi stant and -susceptible genotypes including near-isogenic lines for resistan ce gene Rbs2. Results of brown stem rot evaluation of grafted plants indica te that brown stem rot resistance is conditioned by the root in all resista nce sources evaluated.