Resistência ao arranquio de plantas : potencial critério de seleção em programas de melhoramento genético de soja.

Abstract

Knowing the importance that the root system represents the performance of a cultivar of soybean and the difficulties faced to study it, it was suggested, in this sense, a new methodology to support and accelerate breeding programs on lines and cultivars. For this it was used a new system, simply and quickly, that has been applied in the field measuring the traction required to pull the ground plants of five soybean cultivars and correlate it with its components of yield and other agronomic characteristics. For this, two trials were conducted in the city of Passo Fundo, Rio Grande do Sul State's. The first experiment was conducted in the field and at the phenological stage R 5.2 their plots were subjected to the proposed traction system. At the phenological stage R 5.5, plots were subjected to the Scholander chamber and the infrared thermometer to determine its water content and temperature respectively. In this experiment were also determined the plant height, first insertion vegetable height, number of branches per plant, stem diameter, and yield components. Taking into consideration that the use of the traction plants methodology is destructive, a second trial was conducted in a greenhouse. The same cultivars tested in the experiment developed in the field were deployed on vessels using sieved soil as substrate, in order to scale an entire root system of each tested variety. At the phenological stage R 5.5, the root system of the experimental units were washed and dry matter evaluated. Significant correlations among the variables studied were determined. It was concluded that the traction methodology in removing plants of the soil is a promising tool in soybean breeding programs.