Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/1996
Publication Date: N/A
Technical Abstract: Clones were screened for their reaction to dry top rot, a disease detected in Florida in 1991 that is caused by the soil-borne pathogen, Ligniera vasculorum. Disease reactions were based on disease incidence and severity resulting from the natural infection of plants planted in a field where the soil-borne pathogen was present. Of the 29 CP-clones and 27 CL-clones evaluated: 4 clones (CP 88-1614, CP 88-1196, CP 75-1553, and CL 75-853) were susceptible having above 24% of the stalks infected; 3 clones (CL 72-321, CL 82-3280, and CP 81-1254) were moderately susceptible with 10-16% stalks infected; 15 clones had between 0.5 to 8% stalks infected and 36 clones did not develop dry top rot symptoms. Heritability of dry top rot resistance was determined using progeny of 17 families resulting from seven female parents (3 resistant, 1 intermediate, and 3 susceptible) crossed with five male parents (1 intermediate and 4 resistant). Seedling progeny were transplanted in the field where the pathogen was present. Since little disease was evident in the plant crop, the incidence of dry top rot was determined in the first ratoon crop. A heritability value (h2 = 0.47) was obtained from the regression of the progeny disease incidence on their mid-parent dry top rot incidence.