EFFECT OF NACL SALINITY ON GROWTH, PIGMENT AND MINERAL ELEMENT CONTENTS, AND GAS-EXCHANGE OF BROAD BEAN AND PEA-PLANTS

Increasing salinity of growth medium induced a reduction in growth and transpiration rate. The concentrations of chlorophylls and carotenoid s were increased in most cases in broad bean leaves while in pea plant s they remained more or less unchanged with the rise of salinization u p to 80 mM NaCl. Thereabove a significant decrease in these contents w as observed. A stimulation of the net photosynthetic rate of pea was o bserved at the lowest levels of NaCl but at the highest levels inhibit ory effect was recorded. In broad bean all salinization levels inhibit ed photosynthetic activity, but dark respiration of both plant species was stimulated. The content of Na+ in the roots and shoots of both sp ecies increased at increasing salinity. In broad bean, Ca2+ concentrat ion in shoots and K+ and Ca2+ contents of roots increased at increasin g salinization, while in pea plants, the content of K+ and Ca2+ was al most unaffected by salinity. Salinity induced an increase in the conte nt of these ions in pea roots. Mg2+ content in shoots and roots of bot h broad bean and pea decreased at increasing salinity except in roots of pea, where it was generally increased.