Genetic gain prediction for wheat with different selection criteria

A Cargnin,M.A Souza,A.J.B Pimentel,C.G Machado

doi:10.12702/1984-7033.v07n04a01

Abstract

The objective of this study was to compare different criteria of simultaneous environment selection based on estimated gains to identify the most appropriate ones. Two hundred and forty F2:4 families derived from eight segregating wheat populations were evaluated. The experiments were conducted on the field, with sowings in the summer and the winter, in 2004. The highest gains were estimated by direct selection in each cultivation environment, with negative gain estimates for the indirect response in the other environment. All indices were more adequate for simultaneous selection of environments since the total gains were higher and more evenly distributed in the two environments. The index based on “desired gains” obtained the highest gains in the three situations. Selection indices are advantageous, since the selection efficiency in wheat breeding programs is improved.

Highlights

The diversity in wheat cultivation areas may hold a solution to reduce the variations in total yields, since climate-induced divergences of one region rarely coincide with those of other regions
The variation coefficients between 12.64 and 13.31% expressed good accuracy, which are classified as intermediate values, considered normal for agricultural trials according to Lúcio et al (1999)
The ratio CVg/CVe presented values that were superior to the unit, which according to Cruz and Regazzi (1997) are considered ideal for selection

Summary

Introduction

The diversity in wheat cultivation areas may hold a solution to reduce the variations in total yields, since climate-induced divergences of one region rarely coincide with those of other regions. According to Souza and Ramalho (2001), the cultivation of this grass is an option for crop rotation, to maintain the high yields of summer crops in the central region of Brazil. In this region wheat production is quite successful, the continuity depends on a better adaptation of cultivars to regions and/or sowing times that would make higher gains for the yield potential of this crop possible (Cargnin et al 2006). Selection is frequently based on evaluations of genotype performance in different environments (year, location, sowing date). It is not easy to select superior progenies, since the relevant traits (grain yield) are mostly quantitative due to the strong environmental influence, so that selection in one environment triggers changes in another (Cruz and Regazzi 1997)

Objectives

Methods

Results