A Study of Bunt Resistance and Its Inheritance in Winter Wheat

The development of disease resistance in varieties of crop plants is recognized as an important part of an improvement program. The prevalence of bunt together with the susceptibility of the common Turkey varieties emphasizes the need for testing for resistance in selection work and for using the possibilities existing in genetic recombinations. By use of irrigation at the North Platte Substation, and by delaying planting to secure favorable soil temperature conditions bunt infection is readily obtained. These favorable conditions for experimental purposes as well as the importance of the problem led to the establishment of a permanent irrigated smut nursery in 1928, which is as ideally situated for bunt studies as any in the hard red winter wheat area. Three years data are presented on the reaction of 78 selections to a local collection of bunt and the inheritance of resistance to the same collection in several crosses involving Minturki, Hussar, Sherman, and Beloglina x Minturki-Buffum as the resistant parents. Studies of bunt resistance, including all varieties and selections grown in the winter wheat improvement program at the North Platte Substation and also certain unadapted varieties found to be resistant in other stations, have been carried on during three seasons, 1929 to 1931, inclusive. Inheritance studies were conducted in 1930 and 1931. The irrigated smut nursery at the North Platte Substation is well suited for breeding for bunt resistance in winter wheat. Oro is the most valuable of the available resistant varieties. Bunt infection in winter wheat varieties varies from year to year depending on environmental conditions, especially soil temperature. The percent of infected heads also varies widely from row to row in a susceptible population. This makes definite mendelian analysis very difficult. Advisor: F. D. Kei