Author : Cevdet Dutlu
Publisher :
ISBN 13 :
Total Pages : 108 pages
Book Rating : 4.:/5 (984 download)
Book Synopsis Physiologic Races of Strip Rust (Puccinia Striiformis West.) of Wheat (Triticum Aestivum Vill.) in the Pacific Northwest During 1971 and 1972 by : Cevdet Dutlu
Download or read book Physiologic Races of Strip Rust (Puccinia Striiformis West.) of Wheat (Triticum Aestivum Vill.) in the Pacific Northwest During 1971 and 1972 written by Cevdet Dutlu and published by . This book was released on 1974 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The virulence of 44 isolates of stripe rust (Puccinia striiformis West.) from 33 collections made during 1971 and 1972 were characterized on two sets of differential varieties. The varieties in the "Oregon" set were: Cappelle Desprez, Chinese 166, Dippes Triumph, Druchamp, Etiole de Choisy, Flamingo, Gaines, Golden, Ibis, Leda, Michigan Amber, Moro, Omar, Rubis, Suwon 92 x Omar4, and Yamhill. The varieties in the "U. S." set were: Lemhi, Chinese 166, Heines VII, Moro, Suwon 92 x Omar4, Druchamp and Riebesel 47-51, Races were named using a modification of the recently proposed system of decanery numbers. Each race was designated by two values, e.g., OR 106-362, making a dual system of values. The first number (106) represents varieties showing 3 and 4 infection types and the second (362) those with 2, 3 and 4 infection types. Based on this dual system, 19 physiologic races of stripe rust were identified from the 33 collections. Certain races named by the dual system may be closely related and show a shift in virulence over time. Based on the number of races identified in the Pacific Northwest, from a relatively few collections, a great diversity of races in time and space occurred. More than half of the collections were different races. Two major wheat varieties grown in the Pacific Northwest, Gaines and Nugaines, supported 11 out of the 19 races identified. However, only one race, OR 110-110 (Moro race), was associated with Moro wheat while the other varieties supported two or more races. The Pacific Northwest was partitioned into five distinct wheat growing areas based on geographic plus ecological differences. Race OR 106- 106 was the most widely distributed race and was found in all areas except the Upper Columbia Basin. The widespread distribution of this race may be related to its ability to attack a wide range of commercially grown Pacific Northwest wheat varieties. All of the wheat growing areas had one or more races in common, even though 11 of the 19 races were specific for one of the five designated wheat growing areas. The distribution pattern of stripe rust races, therefore, in the Pacific Northwest is neither area specific nor variety dependent. No race has predominated in the population since 1964. However, there was evidence for a seasonal shift in the race make-up of the stripe rust population. In view of the extensive genetic diversity in the stripe rust population in the Pacific Northwest, there is a potential for stripe rust epidemics on old and new wheat varieties. This danger can be reduced by growing varieties with different genetic backgrounds and by maintaining genetic diversity in the varieties of wheat.
