Published online by Cambridge University Press: 27 March 2009
Grain yield in wheat, as in other crops, is a complex character, made up of many subcharacters. In the present investigation the study of genotypic and phenotypic correlations and path-coefficient analysis indicated that 250-grain wt. and ear number were two important component characters in wheat. Under these circumstances it would be desirable to select those plants which produce large number of tillers and very large and bold sized grains. The greater the number of tillers on a plant the greater would be the number of grains/plant. Again large and bold type of grain would obviously give higher seed wt.
With the use of discriminant functions it was observed that a maximum genetic gain of 7·44% was obtained when grain yield/plant, 250-grain wt., no. of ears/plant and ear length were included in the function. This would suggest that the discriminant function is superior to straight selection in wheat. However, an expected gain of 4·13% was realized when only 250-grain wt. and grain yield/plant were taken into account. In the present analysis it appeared that relatively more emphasis should be given to grain wt. during selection. To make proper use of such characters in selection, their importance must be considered in the definition of economic worth. Progress measured in terms of yield alone will be less when the economic importance of plant type is ignored.