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Soybean seed treatment with zinc: absorption and distribution of zinc during germination, and its relation with initial plant performance

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Author(s):
Lívia Araújo Rohr
Total Authors: 1
Document type: Master's Dissertation
Press: Piracicaba.
Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
Defense date:
Examining board members:
Francisco Guilhien Gomes Junior; Hudson Wallace Pereira de Carvalho; Felipe Lopes da Silva
Advisor: Francisco Guilhien Gomes Junior
Abstract

Seed treatment with micronutrients is an efficient and low operating cost practice that combined with the use of high quality seeds, can bring good results to the productivity of different cultures. For soybeans, zinc (Zn) is a micronutrient that can be limiting to productivity in low fertility soils. However, one of the aspects not yet clarified in relation to the treatment of soybean seeds with Zn is the dynamics and absorption of the nutrient by the seeds and its use by the plants. Thus, this research aimed to evaluate the absorption and distribution dynamics of Zn during the germination of high and low vigor soybean seeds, applying doses of 0, 2, 4 and 8 g of Zn per kg of seed and to verify the effects of these doses on the performance of plants at phenological stage V2. The assessments of Zn absorption and distribution were performed by X-ray fluorescence (µ-XRF) in the seed coat, cotyledon, hilum and embryonic axis of seeds soaked for 8, 16 and 24 hours and in the primary root, hypocotyl, cotyledon and plumule of seedlings with 48, 72 and 96 hours of germination. Plants were cultivated in a controlled enviroment, using sand as substrate, until they reached the phenological stage V2. After that, evaluations of plant height, leaf area, root volume, root dry weight and aerial part and Zn concentration in the root and aerial part were carried out. The data obtained were subjected to analysis of variance and the means were compared using the Tukey test at 5% probability. The mobilization of Zn from the outermost to the innermost region of the cotyledon of high and low vigor seeds occurred with the increase of the imbibition time, following the seed dynamics of water absorption. The intensities of Zn in the embryonic axis of high vigor seeds, treated with doses of 2 and 4 g.kg-1 , were higher than those of low vigor seeds until 16 hours of soaking, however, after 24 hours of soaking the low vigor seeds showed higher intensities of Zn in the embryonic axis. Higher Zn intensities were observed in the primary root and plumule of seedlings originated from low vigor seeds treated with a dose of 2 g.kg-1 . The treatment of seeds with doses of Zn had no effect on the performance of plants in the phenological stage V2. Seeds with different levels of vigor, when treated with Zn, present different behaviors regarding the dynamics of absorption and distribution of this element in the region of the embryonic axis, however, they do not present any difference in behavior in the cotyledon region. (AU)

FAPESP's process: 19/17967-8 - Soybean seed treatment with zinc: absorption and distribution during germination and seedling development evaluated by X-ray spectroscopy and relation with plant performance
Grantee:Lívia Araújo Rohr
Support Opportunities: Scholarships in Brazil - Master