SEGREGATION OF "RED" AND "YELLOW" NEEDLE LESION TYPES AMONG MONOAECIOSPORE LINES OF CRONARTIUM RIBICOLA

Abstract

Monoaeciospore lines of Cronartium ribicola (J. C. Fisch. ex Rabenh.) segregated for needle lesion type to produce a pattern expected from a heterothallic rust. Published evidence and the segregation patterns both support the conclusion that C. ribicola is heterothallic. Segregation for homozygous off-types required further explanation. Aeciospore and urediospore "fertilization" of sporidial infections are hypothesized. The basis for these hypothesized modes of fertilization and the effect they would have on genetic analysis of C. ribicola are discussed.