Proc. of Second World Avocado Congress 1992 p. 572

Evaluation of Germplasm from Guatemala for Resistance to Phytophthora (1982-1990)

M.D. Coffey

Dept of Plant Pathology, University of California, Riverside, CA 92521, USA

E. Schieber

Antigua, Guatemala, Central America

Abstract. In the ten-year period from 1981 to 1990, over 20,000 seeds of Persea americana and Persea schiedeana were collected and sent to Riverside for screening for seedling resistance to Phytophthora cinnamomi. Of these, approximately 30 seedlings were identified in a primary screen as showing some early promise as sources of germplasm for resistant rootstocks. These resistant selections include representatives of the Guatemalan and Mexican races of Persea americana. possible hybrids of these two avocado races, and two other species of Persea, P. schiedeana and P. steyermarkii.