SOURCES OF RESISTANCE TO BEAN RUST PATHOGEN IN SOUTHERN MOZAMBIQUE
Abstract
Mozambique is an African country in which more than 80% of the population practice subsistence agriculture. Most farms are 0.5 to 4.0 hectares where diverse crops are grown using traditional farming methods. Common bean is cultivated in monoculture and more often associated with corn, and the yield average is 750 Kg/ha. Rust caused by Uromyces appendicultus is one of the major constraints to snap and dry bean production in Mozambique. The objectives of this study were to identify pathogenic variability and sources of resistance to bean rust in southern Mozambique. Twenty-four pathotypes of U. appendiculatus were identified based on virulence reaction of 12 differential bean cultivars to 69 rust isolates from southern Mozambique. Most of the Andean bean cultivars with rust resistance genes were susceptible to those isolates. However, cultivars from Middle American origin were resistant to most of the isolates. The Middle American beans provide resistance genes for rust from southern Mozambique. For variety development, one or more of the Middle American Ur-3, Ur-5 and Ur-11 genes and the unknown gene of CNC should be incorporated into adapted bean germplasm as sources of resistance to bean rust pathogen.
Celestina Jochua
Graduate Student
Plant Pathology Department
University of Nebraska-Lincoln