Estimates of genetic parameters in a maize composite and potential for recurrent selection

M.E.A.G.Z Paterniani,R.M Silva,R.R Luders,E Sawazaki,P.B Gallo

doi:10.12702/1984-7033.v04n01a13

Abstract

The genetic variability in the maize composite I - Mo, from the improvement program of the Instituto Agronomico de Campinas (IAC), was evaluated. Eight trials of half-sib families with 25 families each, the composite, and a commercial control AL 30 were conducted at the IAC. Individual and combined variance analyses of trials were performed and genetic variance components estimated for ear yield (EY), plant height (PH), and ear height (EH). A high additive variance value was obtained for EY, in contrast to values found in literature, indicating that composites have large variability and are promising for recurrent selection programs. The VC G/VCE index of 0.7 for EY indicated suitability for selection. Assuming a 20% selection of best families, an expected selection gain of 7.9% was estimated. Composite I - Mo has great genetic variability and a remarkable potential for breeding via recurrent selection, promising considerable selection gains in yield.

Highlights

Population improvement is an essential aspect in corn breeding programs, since it allows the exploitation of genetic variability and an increased frequency of favorable alleles which determine characters of agronomic interest
Eight trials were developed in a randomized complete block design with three replications at the Instituto Agronômico de Campinas (IAC) (Campinas), with 25 families, and the Composite, while variety AL 30 was used as commercial control
Means of the three characters in the eight trials showed that the half-sib families from the maize composite I – Mo did not perform as well as the commercial control (Table 1)

Summary

Introduction

Population improvement is an essential aspect in corn breeding programs, since it allows the exploitation of genetic variability and an increased frequency of favorable alleles which determine characters of agronomic interest. The achievement of new maize varieties via recurrent selection aims mainly at attending the needs of small farmers, which is a goal of the IAC maize improvement program. The selection method among and within half-sib families (Paterniani 1967) has been broadly applied by maize breeders, owing to its relative simple procedure and satisfactory effect (Paterniani and Campos 1999). These authors present results of recurrent selection with half-sib families in several maize populations

Objectives

Methods

Results