Potassium (85rubidium) uptake, translocation and its efficiency use in indeterminate growth type soybean cultivars

• Grant number: 12/13686-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2012
• End date: February 28, 2014
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: José Lavres Junior
• Grantee: Luiz Tadeu Jordão
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

After nitrogen (N), the potassium (K) uptake is generally greater than that of any other macronutrient. Commonly, K deficiency symptoms appear first on older leaves due to high mobility and its redistribution from old to new organs. However, in recent growth seasons in Brazilian soybean areas, it was noticed K deficiency symptoms in young leaves of those cultivars with indeterminate growth type (IGT). Thus, the objectives of this study will evaluate the K-efficiency use and K-efficiency uptake (85Rb) through the K(85Rb)-uptake kinetics parameters (Vmax, Km and Cmin), in order to quantify the relative distribution (%); redistribution of K (85Rb) as related to K-supply, as well as the K-forms of supply; and calculate the critical levels of K in plant tissue and available K soil, as well. The experimental design is randomized complete block with treatments arranged in a factorial 5 x 8 (experiment I); with treatments arranged in a 8x4 factorial experiment (II), and with the treatments arranged in a 5x4 factorial experiment (III), all of them with three replicates. Potassium (85Rb) concentration and accumulation (content) will be assayed in plant tissues (experiments I, II and III), as well as the dry mass, K-distribution (%), K-long distance transport and diamine putrescine content in deficient leaves (experiments II and III). The K (85Rb)-uptake kinetic parameters; total root length; total root surface and root growth rate (experiment I); K-efficiency use and K-efficiency uptake (experiment II); as well as the K-critical levels (Experiment III) will be assayed.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

JORDÃO, Luiz Tadeu. Uptake, redistribution and potassium (rubidium) use efficiency by soybean cultivars with indeterminate growth type. 2014. Master's Dissertation - Universidade de São Paulo (USP). Centro de Energia Nuclear na Agricultura (CENA/STB) Piracicaba.