Relationship between Drought Tolerance and Ageing in Higher Plants I. Mineral Content

Abstract

A comsarison of mineral content was made between leaves of different ages and between plants cultured in various soil moisture conditions using rape (Brassica rapa) and cowpea (Vigna sinensis) as the plant materials. The younger leaves and the whole plant cultured in dry soil contain more potassium and a little more phosphorus but less calcium than the older leaves or the whole plant in wet soils, respectively. Magnesium and sodium contents showed, however, very little differences in these comparisons. It may be said that the development of drought tolerance in a plant through drought hardening seems to relate with some features similar to those in younger leaves of the plant with respect to mineral contents.
The sum of cations, total millimoles and total milliequivalents, was usually maintained at almost constant levels in one experimental series.