An extended range for oak wilt and Ceratocystis fagacearum compatibility types in the United States

Abstract

Oak wilt, caused by Ceratocystis fagacearum (Bretz) Hunt, has been found in 31 Texas counties, significantly extending the southern range of the disease in the United States. The 101 isolates obtained from 76 diseased oaks in 22 of those counties were assayed for sexual compatibility using a paired plug or spermatizing technique. There were 51 type A isolates and 44 type B isolates; 6 of the isolates could not be typed. A majority of multiple-tree infection centers contained only one compatibility type and only one diseased tree yielded both compatibility types. The distribution of compatibility types and behavior of C. fagacearum in Texas are consistent with those observed in other states.