RACES OF PUCCINIA-GRAMINIS IN THE UNITED-STATES DURING 1995

Wheat stem rust overwintered in southern Louisiana, southern Texas, so uthwestern Georgia, northeastern Arkansas, and southwestern South Caro lina in the winter of 1994-95. Wheat stem rust caused negligible yield losses in wheat in the United States, Races Pgt-TPMK and QCCJ made up 39 and 31% of all isolates, respectively. Race TPMK comprised 67% of isolates from farm fields. Race Pgt-QCCJ was most common from barley, making up 93% from 47 collections. Six collections from Hordeum jubatu m yielded six isolates each of races QCCJ and QFCS, and one isolate of race TPMK. No virulence was found to wheat lines with genes Sr6, 9b, 13, 22, 24, 25, 26, 27, 29, 30, 31, 32, 33, 37, Gt, or Wdl-1. Oat stem rust overwintered in plots at Beeville and Temple, Texas, in a field near San Antonio, and in southern Louisiana. Yield losses due to oat s tem rust in 1995 were negligible. Race NA-27, virulent to Pg-1, -2, -3 , -4, and -8, was again the predominant race in the United States, com prising 82% of the 225 isolates from 80 collections. NA-5 and NA-16 we re the two other races identified from the United States, comprising 1 1 and 19% of the isolates. Only race NA-29 was found in four collectio ns from Mexico.