INHERITANCE OF BEAN RESISTANCE TO RUST ATTACK (Uromyces phaseoli typica, Art) IN RELATION TO GROWTH HABIT

Abstract

Five different croases among six bean varieties and their reaction to three physiological races of the bean rust Uromyces pha­seoli-typica Arth. were studied. The objetive was to determine the inheritance of resistance to the disease and its relation with the growth habit of the plant. Rust races 13, 18 and 29 were used. Resulta in F₁ progenies indicated complete dominance for rust resistance and determined growth. Results in F₂  indicated monogenic type of inheri­tance for the two characters as well as independence between the two gene pairs. The observed asocciation between the traits, determined growth habit and resistance to rust, therefore, is not due to linkage between the two gene pairs but rather to the strong autogamy of this plant which has prevented genetic exchange among the adapted bean varieties. Resulta from crossing and selecting sinniultanceously for both rust resistant and indeterminate growth plant type have not been successful because selection has been carried out under field con­ditions where the patogen may not develop.