Analysis of germination and vigor of cashew seeds for germplasm conservation by NMR and uPLC-qTOF-MS/MS based metabolomics

Abstract

The effective preservation of cashew germplasm faces significant challenges due to the loss of germination vigor over medium and long periods. Therefore, this study aimed to assess the biometric and chemical parameters that determine the germination and vigor of cashew seed. Seeds from seven cashew genotypes stored under refrigeration (18 ± 2 °C) were evaluated for biometric characteristics and post-emergence development analyzed by NMR, UPLC-QTOF-MS^E and GC–MS methods for profiling primary and secondary metabolites along with fatty acids. The evaluated materials revealed significant variability in emergence percentage (0 % to 91.43 %), exhibiting a negative correlation with biometric characteristics. The emergence speed index (ESI) and emergence speed (ES) ranged from 1.20 to 3.61 and 16.58 to 22.84 days, respectively. The oleic acid is the major fatty acid (60 %) and the correlation of the fatty acid content with emergency remain unclear. The NMR and UPLC-QTOF-MS^E analysis highlighted the compositional variability among the genotypes. In this regard, NMR and statistical modeling shows positive correlation which seeds with higher stachyose and acetic acid and lower sucrose contents exhibited greater germination. Additionally, seeds with enhanced germination parameters positively correlated with greater phenolic lipids content, such as anacardic acids. Therefore, this study indicates that seeds with reduced biometric parameters that presented increased content of stachyose, acetic acid, and anacardic acids were correlated higher emergence capacity making those seeds more suitable to cashew germplasm cryopreservation banks.