Genetic divergence and path analysis in wheat cultivars under heat stress

Carlos Eduardo Da Silva Oliveira,André Zoz,Tiago Zoz,Agner De Freitas Andrade,Renato Lustosa Sobrinho

doi:10.1590/1983-40632020v5065493

Abstract

ABSTRACT One of the biggest limitations for the wheat crop expansion to Brazilian tropical regions is the high temperature in the rainy season. This study aimed to select, based on genetic divergence and path analysis, cultivars that tolerate cultivation in the summer (heat stress). Nine wheat cultivars were sown, using a randomized block design with three replications, with plots consisting of 10 rows of 6 m and row spacing of 0.15 m. The highest grain yield and number of ears m-2 were observed for the CD 150 cultivar and the largest 1,000-grain weight for CD 116. BRS 220, IPR 136, IPR 144 and BRS Pardela had the highest number of sterile spikelets. The highest number of grains per ear was observed for CD 150, CD 116, BRS Pardela, IPR 130 and IPR 85, showing direct effects on grain yield, evidenced by the path analysis. CD 116 and CD 150 were the most productive cultivars and can be considered as possible parents in wheat breeding programs. IPR 85, CD 116, CD 108 and CD 150 showed a greater tolerance to high temperatures.

Highlights

The wheat cultivation in Brazil was predominant in a temperate climate zone extending from the Rio Grande do Sul to the Paraná state (Cargnin et al 2006)
There was difference between the wheat cultivars for number of ears m-2, plant height, number of sterile spikelets per ear, number of grains per ear, 1000-grain weight and grain yield (Table 3)
It can be said that there is genetic variability among the wheat cultivars evaluated under heat-stress conditions

Summary

Introduction

The wheat cultivation in Brazil was predominant in a temperate climate zone extending from the Rio Grande do Sul to the Paraná state (Cargnin et al 2006). As it presents adequate climatic conditions for the development of this cereal, southern Brazil still has the largest cultivated area (2.1 million hectares) (Conab 2020). In the 1970s, wheat began to be cultivated on a commercial scale in the central region of Brazil (São Paulo, Minas Gerais, Goiás, Mato Grosso and Mato Grosso do Sul states), and, since the 1990s, it has been cultivated in Brazilian Savanna soils, under no-tillage, reaching high grain yields (Souza & Ramalho 2001).

Objectives

Methods

Results

Conclusion