Relationship between biochemical and photosynthetic traits with Asian soybean rust

Abstract

Asian soybean rust (Phakopsora pachyrhizi-ASR) is one of the major diseases that occur in soybean and causes great damage to commercial crops. Therefore, the goal of this work was to investigate the relationship between biochemical and photosyntetic parameters in soybean with ASR. Two experiments were performed in a randomized complete block with three treatments (water, Tween 20, and methyl jasmonate). The evaluated traits were: severity, chlorophyll pools, concentration of phenolic compounds content, enzyme activity, and photosyntetic parameters. Based on Pearson correlation, correlation network and path analysis it was verified that the severity had high correlation with almost all traits evaluated meanwhile photosynthesis is weakly related with almost all traits. Therefore, the occurrence of ASR affects directly the traits related to enzymatic activity and phenolic compounds content in soybean plants inoculated with ASR. The management of ASR is important to keep in normal levels the rates of photosynthesis carried out by the plant, and thus not affect the yield. Besides that, understanding the biochemical mechanisms and ecophysiological responses that occur during the soybean-P. pachyrhizi interaction has a great importance for breeding programs, as it will help for obtaining resistant cultivars or efficient methods in fungus control.

Physiological response and earliness of soybean genotypes to soil base saturation conditions

“…It is important to highlight that the coefficient of variation (CV) over the two crop seasons were less than 10%, revealing high experimental accuracy. The CV obtained here was similar to the values reported other studies assessing physiological traits in soybean (Oliveira, de Azevedo Peixoto, et al., 2018; Oliveira, Peixoto, et al., 2018; Teodoro et al., 2019; Zobiole et al., 2010).…”

“…At 60 days after emergence (DAE), physiological traits were analysed using a portable photosynthesis analyser ( Infrared Gas Analyser —IRGA) model Li‐6400XT (LiCor Inc., Lincoln, Nebraska, USA). Photosynthetically active photon flux of 1,044 μmol m −2 s −1 and environment CO 2 concentrations (372 ± 10 mol m −2 s −1 ) were used, according to similar studies evaluating gas exchange in soybean crop (Oliveira, de Azevedo Peixoto, et al., 2018; Oliveira, Peixoto, et al., 2018). The physiological traits measured were as follows: net photosynthesis (A, μmmol CO 2 m −2 s −1 ), transpiration (E, mmol H 2 O m −2 s −1 ), stomatal conductance (gs, mol m −2 s −1 ) and internal CO 2 concentration (Ci, μmmol m −2 s −1 ).…”

Understanding the combining ability for physiological traits in soybean

“…The coefficients of variation (CV) less than 4% show high experimental accuracy and are lower than the values reported in the literature [30, 31, 37, 38]. After conducting the experiments in two crop seasons, it was observed that the genotype x environment interaction was not significant for all traits evaluated.…”

“…At 60 days after emergence (DAE), physiological traits were analyzed using a portable photosynthesis analyzer ( Infrared Gas Analyzer —IRGA) model Li-6400XT (LiCor Inc., Lincoln, Nebraska, USA). Photosynthetically active photon flux of 1044 μmol m -2 s -1 and environment CO 2 concentrations (372 ± 10 mol m -2 s -1 ) were used, according to similar studies evaluating gas exchange in soybean crop [30, 31]. The physiological traits measured were: net photosynthesis (A, mmol CO 2 m -2 s -1 ), transpiration (E, mmol H 2 O m -2 s -1 ), stomatal conductance (gs, mmol m -2 s -1 ), and internal CO 2 concentration (Ci, mmol m -2 s -1 ).…”

Efeito da limitação hídrica no patossistema >i<Phakopsora pachyrhizi>/i<-soja

“…A soja é um dos principais produtos de exportação do agronegócio brasileiro, e também a cultura que mais cresceu em território nacional nas últimas três décadas. O setor agro, por sua vez, é um dos mais influentes na balança comercial da economia brasileira (OLIVEIRA et al, 2018). Do ponto de vista constitutivo, o grão da maioria das cultivares de soja possue na faixa de 30 a 45% de proteína e 15 a 25% de óleo (BORDINGNON; MANDARINO, 1994).…”