DRUSES IN THE SECONDARY XYLEM OF MANGIFERA INDICA COLLECTED FROM COAL MINES, INDIA

Abstract

The study was undertaken to understand the influence of mining stress on the wood structure of tropical hardwood tree species. Dhanbad district in Jharkhand is the coal capital of India, and it is one of the most polluted areas of the world which makes it an ideal area of study to assess the mining stress on tropical hardwoods. Samples of mature wood were taken from the outer core of the sapwood of several hardwood tree species including seven samples of Mangifera indica along the fringes of the coal mines. Qualitative and quantitative features of the samples were studied. A conspicuous observation was made at the occurrence of druses in the ray parenchyma cells of a stressed M. indica wood sample. The druses appeared as dense globular form, and the constituent units were like rose petals to glass flakes, representing a solid druse type. The occurrence of druses in M. indica has not been reported earlier. The presence of druses in a single sample of M. indica, out of seven, can be accounted to the adaptation of the individual plant to the local microclimatic conditions or side effect due to mining stress.