Details

Autor(en) / Beteiligte

• Pratt, R.C
• Anderson, R.J
• Louie, R
• McMullen, M.D
• Knoke, J.K

Titel

Maize responses to a severe isolate to maize chlorotic dwarf virus

Ist Teil von

• Crop science, 1994-05, Vol.34 (3), p.635-641

Ort / Verlag

Madison, WI: Crop Science Society of America

Erscheinungsjahr

1994

Link zum Volltext

Beschreibungen/Notizen

• The results of incidence ratings to assess the host response of maize (Zea mays L.) to natural infection, or to controlled inoculation in either the field or the greenhouse, with maize chlorotic dwarf virus (MCDV) appear inconsistent for identification of resistant or tolerant responses. Our objective was to determine whether assessment of the severity of three symptoms on the leaves (veinbanding, chlorosis, and twisting of the leaf and tearing of the leaf margin) would consistently allow differentiation of the host responses of maize inbreds and hybrids to inoculation with two isolates of MCDV. Symptom severity was assessed using a 1 to 5 visual rating for each of the three symptoms at three to four time intervals after controlled inoculation with a severe isolate of MCDV in both greenhouse and field experiments. Analysis of the symptom severity assessments grouped genotypes into similar host response categories in both environments. Incidence ratings of genotypes in greenhouse studies were not significantly different, and field incidence ratings were inconsistent. Height reduction in greenhouse-grown plants was most severe in genotypes with high levels of expression of the other symptoms but was of limited value in differentiating genotypic groups. Comparison of the average symptom severity assessments using the severe and type isolates indicated that symptom expression in field-grown plants was more severe when inoculated with the severe isolate of MCDV. Regardless of virus isolate, symptoms of plants grown in the field were not as severe as those on plants grown in the greenhouse. A reduction in symptom severity was associated with hybrid vigor of field-grown plants. In one field study, the level of symptom severity was correlated with both yield and plant height reduction of hybrids