Cell Wall Composition of Smooth Bromegrass Plants Selected for Divergent Fiber Concentration

• Published in: Journal of agricultural and food chemistry 2006-10, Vol.54 (21), p.8206-8211
• Main Authors: Casler, M. D, Hatfield, R. D
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Bromus - chemistry; Bromus - ultrastructure; Bromus inermis; carbohydrate content; Carbohydrates - analysis; Cell Wall - chemistry; cell wall components; cell walls; clones; Dietary Fiber - analysis; fiber content; Food industries; forage grasses; forage quality; Fundamental and applied biological sciences. Psychology; lignin; neutral detergent fiber; Plant Leaves - chemistry; Plant Leaves - ultrastructure; Plant Stems - chemistry; Plant Stems - ultrastructure; sugars; uronic acids
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf060319o

Neutral detergent fiber (NDF) is considered the single best laboratory predictor of voluntary intake by ruminant livestock, creating interest in using NDF as a selection criterion in forage breeding programs. Because genetic reductions in NDF lead to increases in dry matter digestibility but not to changes in digestibility of the NDF fraction, we postulated that low-NDF plants do not have altered compositions of their cell walls. We tested this hypothesis using clones of smooth bromegrass (Bromus inermis Leyss.) with divergent NDF concentrations. High-NDF and low-NDF plants did not differ in cell wall concentrations or in the concentrations of any cell wall component (fucose, arabinose, rhamnose, galactose, glucose, xylose, mannose, uronic acids, and lignin). Instead, low-NDF plants had a cell wall that was more susceptible to solubilization in neutral detergent solution, suggesting that their cell walls were less well-developed as compared to high-NDF plants. NDF should not be used as a substitute for cell wall concentration in forage plants. Keywords: Neutral sugars; lignin; NDF; Bromus inermis