BIODIVERSITY, EPIDEMIOLOGY AND VIRULENCE OF COLLETOTRICHUM-GLOEOSPORIOIDES - III - FIELD-EVALUATION OF STYLOSANTHES SPECIES FOR ANTHRACNOSERESISTANCE IN THEIR CENTER OF DIVERSITY

A total of 72 accessions and cultivars of Stylosanthes scabra, S. guia nensis, S. capitata and S. macrocephala were evaluated for their react ion to anthracnose (caused by Colletotrichum gloeosporioides) at 4 sit es, 2 in Brazil and 2 in Colombia. Severe disease epidemics occurred a t Planaltina (Brazil) and Carimagua (Colombia) but few accessions were damaged by disease at the other 2 sites. A wide range of disease dama ge was recorded across accessions within species and there were pronou nced site x accession interactions in the anthracnose reactions. S. gu ianensis cv. Mineirao was outstanding for resistance at Planaltina, th e site where disease was most severe. Control accessions of S. scabra showing strong resistance in Australia, cv. Seca and CPI 93116, also s howed good resistance in Planaltina, Although the 20 bred lines of S. scabra were generally more damaged by anthracnose at Planaltina than i n Australia, disease ratings at Southedge, Queensland, were a good pre dictor of the most resistant lines at Planaltina.