Caracterização do sistema radicular de cultivares de feijão

Abstract

The bean (Phaseolus vulgaris L.) has high nutritional content, its components that stand out are proteins, carbohydrates and iron. It presents an underdeveloped root system, distributed mainly in the superficial layer of the soil in an average depth of 20 cm. Knowledge of root attributes, as well as their relationships with the environment, are limited at the scientific level for this crop. The root system has essential attributes for plant establishment and development, among its most important functions stand out the support of the plant to the soil, and the absorption of water and nutrients. The study of the root system is of great importance for the genetic improvement and positioning of plants in ideal conditions for its cultivation. The objective of the present work was to characterize the root system of 12 common bean cultivars. The experiment was conducted in a uniform culture environment under PVC pipes in a greenhouse at the Federal Technological University of Paraná, Campus Pato Branco - PR, with a randomized block design in a one - step scheme and four replicates, consisting of twelve bean cultivars. As the plants reached the reproductive stage R6 were evaluated the length of aerial part (CPA), root length (CR), fresh root matter (MFR), shoot fresh matter (MFPA), root surface area (ASR) , root volume (VR), shoot dry matter (MSPA) and root dry matter (MSR). The results showed a significant difference (p <0.01) for most of the characters, not differing only in CR and ASR. The comparison test between Scott and Knott averages (p <0.05) demonstrated that BRSMG Madrepérola was superior to MFR and VR, IPR Colibri MSR and Tangará MFPA. There was a significant and positive correlation (p <0.05) between: MSR and MFPA, MFR and RV, MSPA and MFPA, and MFPA and CPA. The MFR contributed with the greatest divergence between cultivars. The MFR, MSR and VR characters represented 85.12% of the observed genetic variability, contributing with 38.68%, 29.92% and 16.52%, respectively. In the cluster analysis two groups were observed, the first consisting of 11 cultivars, which formed two subgroups. In the subgroup I, cultivars with intermediate root development (IAC Milênio, IPR Tuiuiu, BRS Campeiro, IPR Campos Gerais, IPR Colibri and IPR Tangará) and subgroup II, cultivars with lower root development (BRS Esplendor, IAC Imperador, ANfc 9, TAA Dama). The cultivar BRSMG Madrepérola represented an isolated group due to its greater root development.