Phosphorus uptake and use efficiency of diverse brazilian rice and common bean cultlivars

Author(s)

Nericlenes Chaves Marcante

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2015-08-26

Examining board members

Takashi Muraoka; Roberto Lyra Villas Boas; Edson Luiz Mendes Coutinho; Paulo Sergio Pavinato; Raffaella Rossetto

• Advisor: Takashi Muraoka

Abstract

The phosphorus (P) is an essential element for all life forms on our planet and plays a crucial role in world agriculture. However, its scarcity will increase in next decades. The world population has reached 7.3 billions people and is projected for 9 billions by 2050. To support this growing population, global agriculture will have to triplicate food production in the next 35 years. The P utilization efficiency is defined as the increased amount of biomass or a product of economic interest (fruit, grains, fibers and ethanol) obtained per unit of absorbed P. The use of high nutrient efficient plants may represent the foundation in building agriculture with high productivity, reduced production costs and low environmental impact. The hypothesis tested in this study was that there is genetic variation among the commercial cultivars of rice and common beans and it is possible to identify plant traits linked with increased P uptake and utilization efficiency. The aim of this study was to identify more P efficient rice and beans cultivars and identify plant traits that may be linked with increased P use efficiency. We carried out a set of experiments (greenhouse and field) in order to check the genetic variability among 16 and 19 rice and bean cultivars, respectively, in high and low soil P availability. The root anatomical traits of a group of bean genotypes were evaluated through experiments conducted in the United States. The results from the experiments showed that there was significant variation among cultivars for most of evaluated traits. We observed substantial genotypic variation among the bean cultivar for basal root whorl number and basal root number. Rice cultivars were similar to shoot production in high P availability, however varied among them in low P availability. The rice and bean cultivars P use efficiency increased in low P. The results of bean anatomic root traits confirmed the hypothesis that basal root etiolation improves bean plants growth under P limiting conditions by increasing P acquisition. The genetic variation for P use efficiency among rice and bean cultivars was confirmed. (AU)

• FAPESP's process: 11/09039-1 - Assessment of efficiency of phosphorus uptake by rice and bean genotypes related to root architecture, using the isotopic dilution technique with 32P and 33P
• Grantee: Nericlenes Chaves Marcante
• Support Opportunities: Scholarships in Brazil - Doctorate