Inheritance of resistance to anthracnose stalk rot of corn

Abstract

Inheritance of resistance to anthracnose stalk rot (ASR) of corn (Zea mays L.), caused by Colletotrichum graminicola was studied in eight crosses involving two resistant inbred lines DW1035 ((MP305 x FRB73\sp{\lbrack 5\rbrack })\sb{\rm S8}) and DW890 ((MP305 x FRB73\sp{\lbrack 5\rbrack })\sb{\rm S8}), and four susceptible inbred lines FRB73, B84, FRMo17, and C103. In 1987, the crosses consisted of the parental lines, F\sb1, F\sb2, and both backcross generations. In 1988 and 1989 the study included F\sb3 and backcross selfed lines. Individual observed stalk rot reactions within a particular generation were classified as resistant or susceptible by discriminant analysis. Expected stalk rot distributions were determined using a partitioning method for a single, dominant gene hypothesis. The observed distributions were compared for goodness-of-fit to the expected distributions using a chi-square test for homogeneity. Support exists with the FRB73 x DW1035 and B84 x DW890 crosses for a single, dominant gene for ASR resistance, but environmental stresses in 1988 and 1989 significantly hindered the ability to obtain conclusive evidence, especially in the B84 x DW1035 population. The data also suggest differences between the resistant inbred lines DW1035 and DW890. Use of FRMo17 and C103 as susceptible parents to interpret the inheritance of a stalk rot with DW1035 and DW890 were complicated by the inability to distinguish the resistant and susceptible parents as two distinct classes.U of I OnlyETDs are only available to UIUC Users without author permissio