Scanning Electron Microscopy of Microorganisms on the Roots of Wheat A. D. R O V I R A ~ AND R. C A M P B E L L
Department of Botany, The University, Briston, BS8 lUG
Abstract The scanning electron microscope was used to study the microorganisms on wheat roots grown in both soil and sand. Bacteria became common on the root surface only in the root hair region of young roots; nearer the tip of the root they were rare. Older roots had relatively high populations of bacteria. Bacteria were sometimes embedded in mucilage, of either plant or microbial origin, which seemed to bind the bacteria firmly to the root surface. Mineral grains on or near the roots of wheat were generally free of mucilage.
Introduction Following the successful d e v e l o p m e n t o f m e t h o d s for p r e p a r i n g r o o t s and adhering microorganisms for the scanning electron m i c r o s c o p e (SEM) by Campbell and Rovira [ 1 ] , a s t u d y was m a d e o f the microflora on the r o o t surface (rhizoplane) o f wheat. The results o f this s t u d y are r e p o r t e d in this paper.
Materials and Methods Wheat (Triticum aestivum L. cv. Capelle) was grown in washed river sand (90% of particles between 210 and 500 urn) supplemented with nutrient solution [3], and in soil from a natural grassland with a pH 4.8, 6.2% organic matter (wet digestion) and a mechanical analysis of 2% fine gravel (>2.0 ram), 8% sand (0.2 - 2.0 mm), 17% fine sand (0.06 0.2 mm), 46% silt (0.002 - 0.06 mm), and 27% clay (
Department of Botany, The University, Briston, BS8 lUG
Abstract The scanning electron microscope was used to study the microorganisms on wheat roots grown in both soil and sand. Bacteria became common on the root surface only in the root hair region of young roots; nearer the tip of the root they were rare. Older roots had relatively high populations of bacteria. Bacteria were sometimes embedded in mucilage, of either plant or microbial origin, which seemed to bind the bacteria firmly to the root surface. Mineral grains on or near the roots of wheat were generally free of mucilage.
Introduction Following the successful d e v e l o p m e n t o f m e t h o d s for p r e p a r i n g r o o t s and adhering microorganisms for the scanning electron m i c r o s c o p e (SEM) by Campbell and Rovira [ 1 ] , a s t u d y was m a d e o f the microflora on the r o o t surface (rhizoplane) o f wheat. The results o f this s t u d y are r e p o r t e d in this paper.
Materials and Methods Wheat (Triticum aestivum L. cv. Capelle) was grown in washed river sand (90% of particles between 210 and 500 urn) supplemented with nutrient solution [3], and in soil from a natural grassland with a pH 4.8, 6.2% organic matter (wet digestion) and a mechanical analysis of 2% fine gravel (>2.0 ram), 8% sand (0.2 - 2.0 mm), 17% fine sand (0.06 0.2 mm), 46% silt (0.002 - 0.06 mm), and 27% clay (
