Genotypic Difference in Molecular Spectral Features of Cellulosic Compounds and Nutrient Supply in Barley: A Review

Abstract

The objective of this chapter was to review four studies from our lab on genotypic difference in molecular spectral features of cellulosic compounds in hull, endosperm and whole seeds of barley grown in Western Canada using advanced molecular spectroscopy techniques – synchrotron-based SR-IMS and DRIFT techniques and nutrient utilization availability profiles in barley. The emphasis of this review is to focus on molecular spectral analysis methodology, results summary and implications. In study 1, the synchrotron experiments were carried out in Canadian Light Source (CLS, Saskatoon) and National Synchrotron Light Sources (NSLS) and Brookhaven National Laboratory (New York, US Department of Energy) to study genotypic effect on spectral feature in endosperm tissue within cellular and subcellular dimension. In study 2, the DRIFT experiments were carried out in Saskatchewan Structure Science Center (SSSC, University of Saskatchewan) to study genotypic effect on spectral features in hull and whole seed tissues. The mole-cular spectral features included ca. 1,293–1,212 cm−1which were attributed mainly to cellulosic compounds in the hull, ca. 1,273–1,217 cm−1which were attributed mainly to cellulosic compounds in the endosperm and ca. 1,269–1,217 cm−1which were attributed mainly to cellulosic compound in the whole seeds. Spectral analyses included univariate and multivariate molecular analyses including an agglomerative hierarchical cluster and principal component spectral analyses. In study 3, in situ and in vitro experiments were carried out to study genotypic effect on degradation kinetics, degradation rate and effective degradability. In study 4, nutrient modelling was applied to study genotypic effect on predicted nutrient supply to ruminants. Our results showed that (1) the molecular spectral techniques (synchrotron SR-IMS and DFIRT) plus agglomerative hierarchical cluster and principal component spectral analyses were able to reveal cellulosic compounds spectral features and were able to identify molecular structure spectral differences at a spatial resolution among the barley genotypes; (2) genotype did have significant effect on nutrient utilization and nutrient supply to ruminants.