NMR metabolite profiling analysis of pigmented rice resistance to rice ear bug

Rice ear bugs or Leptocorisa oratorius F. are major rice pests reported to reduce the rice yields severely. The present study aimed to screen local pigmented cultivars for resistance to rice ear bugs and perform metabolomics analysis to identify the metabolites responsible for the resistance character. For screening, eight cultivars including both black and red varieties were used. Rice ear bugs used for bioassay were collected from the field. The assay results showed that two cultivars of black rice and one cultivar of red rice exhibited high resistance characters as per the Standard Evaluation System guidelines for rice. Metabolite profiling of rice seeds was performed at the milky stage using 500 Mhz NMR JEOL, followed by multivariate analysis with SIMCA ver 14. Metabolite profiling identified nine out of 15 metabolites, which were significantly different between the most resistant and susceptible cultivars. In the red rice, hydroxy-L-proline, threonine and formic acid and for black rice, valine, glutamate, α-glucose, β-glucose, galactinol and raffinose were identified as potential metabolites conferring the resistance character. This study identified the most resistant cultivars which can be used in the future to support the development of a novel line of cultivar resistant to rice ear bug. © 2021 World Research Association. All rights reserved

Length/weight relationship and condition factor of Macrobrachium jelskii (Miers, 1877) and M. brasiliense (Heller, 1862) (Decapoda, Palaemonidae) in two locations in the state of São Paulo

Abstract This study describes the weight vs. carapace length relationship and provides the total and monthly condition factor values for populations of Macrobrachium jelskii (Miers, 1977) and M. brasiliense (Heller, 1868) occurring in southeastern Brazil. The biological characteristics were compared and related to the climatic environmental factors between the two areas. Our investigation sampled M. jelskii from the Barra Mansa Dam, Mendonça, SP, a semilotic environment with greater resilience than the Talhadinho Stream, Talhado, SP, a lotic environment where specimens of M. brasiliense were captured. Individuals were classified according to sex and measured at the carapace length (CL) and weighed (WE). The relationship WE/CL was analyzed by dispersion diagrams of the empirical points, which were set to the power function (WE = a.CL b ). Values of the mean condition factor were compared monthly. In total, 1493 individuals of M. jelskii and 843 individuals of M. brasiliense were captured. Analyses of the constant allometry revealed that both sexes of M. jelskii, as well as females of M. brasiliense grow proportionately more in size than weight. The results concerning the morphometric aspects studied in both species suggest an association with the reproductive processes