Histological arrangements of plant tissue of different elephant grasses as influenced by their genotypes

Abstract

Elephant grass genotypes display a variety of morphological differences, influencing the nutritive value of the forage. This study evaluated the histological arrangements of the leaves and stems of different elephant-grass genotypes, two tall-sized (Elephant B and IRI-381) and two dwarfs (Mott and Taiwan A-146 2.37), during a two-year trial. The grasses were harvested at 60-day intervals for two years. Biometric analyses of the stems and leaves were performed based on histological measurements. An in vitro dry matter digestibility (IVDMD) assay of the forage was performed. Among the elephant grass genotypes, the lignified cells and vascular bundles of the stems had higher variation than the leaves. Tall-sized genotypes displayed more lignified tissues in stems than the dwarfs. The transversal area occupied by vascular bundles and lignified cells were higher in Elephant B (44 911 μm² and 35 895 μm²) (p < 0.05), compared to the dwarfs. Forage IVDMD was higher in leaves (699 g kg⁻¹ of dry matter [DM]) than in the stems (678 g kg⁻¹ of DM), considering all genotypes (p < 0.05). We did not observe any direct influence of genotype on forage digestibility, despite some differences in the histological arrangements.