Grain yield in indirect selection for multiple characters in upland rice

Abstract

The aim of the present study was to compare the selection performed by the sum of standardized variables index (Z Index) with the selection based only on the grain yield character, to verify if the grain yield alone is a good alternative for the selection involving multiple characters. The experiments were conducted in Lavras-MG and in Lambari-MG, during the 2015/2016 agricultural year. The used design was the randomized complete block design with 3 replications. Thirty-six genotypes of the preliminary trial of upland rice breeding program of the Federal University of Lavras were evaluated. In order to compose the Z index, the following characteristics were evaluated: grain yield, height, number of days for flowering, 1000-grain weight, income, yield, leaf blast incidence, and grain length/width ratio. Z index was efficient in the selection for multiple characters whereas not all lines with the highest grain yield obtained good results in the other desirable characteristics, indicating that the selection based only on grain yield is not efficient when working with several characters of interest in upland rice cultivation.