Abstract
Two experiments, one each of spring of winter wheat were planted in 1980-181 crop season in a control and au inoculated section with six replications in each at Montana State Univereity,. Field Research Laboratory. The spring wheat experiment had three populations derived from three crosses and winter wheat had two popuiationa derived from t erotism Each population eon. Aisted of two generations; F4 and Fei in the spring wheat and F3 and F5 in the winter wheat, respectively, The P5 and 106 Were Seleoted earlier for minor gene reeietance in F2 and F-3 generations, The two generations in each population (F6 Va., F4 and F, VS, rj) were compared. using t-test, for disease resistance, grain yield, plant height, biological yield, harvest index, straw weight, growth rate, tillers number and kernel weight, Selection for minor genes wee effeotive in two crosses in spring wheat and one 1211:11215 in winter wheat. Increase in resistance, how-ever, -vas actompanied with deareaee in grain yield. Tiller number, straw weight., biological yield! growth rate and harvest index also Buffered decline in two of the three crosses. The crosses which showed no increase in resistance suffered au decline in say trait.. It is, therefore, assumed that the decline la grain yield and other traits was assoeinted with the accumulation of minor genes.
INTRODUCTION
Selection of trait may result in an assooialted intrease or decrease in the other traits. Such correlated response can tean from genetic linkage or pled °. tropic effect of one gene on the other (Allared, I980), Presence of awns in wheat was reported to influence the yield and test weight, Selection of awned version of a variety (Ones) out yielded awnless version of the same variety in grain yield and test -weight. (Sun,elson et Z. 1919).
