Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 10/10/1995
Publication Date: N/A
Technical Abstract: Soybean embryogenic suspension cultures established from cv. Jack immature cotyledons were selected for their insensitivity to toxic culture filtrates of Fusarium solani, the causal agent of soybean sudden death syndrome (SDS). The embryogenic cultures were challenged with a sublethal concentration of fungal culture filtrates for 1 to 2 months. Those surviving embryogenic cultures were transferred to regeneration medium. Out of 74 plants regenerated, 69 set seeds. The R1 (first-selfed generation) and R2 plants of regenerants were inoculated with a F. solani SDS isolate. The foliar severity was rated on a 1 to 5 scale: 1 = no foliar symptoms to 5 = interveinal necrosis and drying of both unifoliate and trifoliate leaves. Of the regenerants, 1% of each of the R1 and R2 plants had a foliar severity of 1; 29% of the R1 and 26% of the R2 plants were rated 2 or 3; and 70% of the R1 and 72% of the R2 plants were rated 4 or 5. Of the nonregenerated control plants, 11% were rated 2 or 3 and 89% were rated 4 or 5. Plants in the R1 and R2 generations were more resistant than nonregenerated control plants to F. solani, indicating that the resistance may be heritable.