Physiologic Races of Hemileia uastatrix B.& Br

Abstract

The genetic study of resistance to Hemileia vastatrix B. & Br. in Coffea spp. was first attempted in India where two factors were reported as being responsible for resistance of some local selections to the more prevalent races. An International Center fo rtesting for resistance to coffee rust varieties was subsequently established in Portugal and is known as the Centro de Investigacao das Ferrugens de Cafeeior (CIFC). At this Center, 24 physiological groups of coffee were used for identifying 30 races of H. vastatrix. The rust races identified in 938 rust isolates from 37 countries were : race II in 58.2 percent, race I in 14.4 percent, race III in 8.9 percent, and race XV in 3.6 percent. All other races were recorde only in trace amounts. The distribution of the races in the 37 countries follows the same pattern; with race II present in 34 of the countries surveyed, race I in 18, race III in 14, and race XV in 8.
In 1978 - 79, 26 rust samples from several coffee growing areas of Thailand were sent to CIFC for race identification. One sample was established as race III and the remainder were all race. II.