DIFFERENCES IN DROUGHT TOLERANCE BETWEEN CULTIVARS OF FIELD BEAN AND FIELD PEA - MORPHOLOGICAL-CHARACTERISTICS, GERMINATION AND SEEDLING GROWTH

Different responses among legume species were observed. but the morpho logical and physiological differences that confer drought resistance o r susceptibility are not well explained. The objective of this study w as the determination of variation of morphological characteristics wit hin 7 field bean and 4 field pea cultivars as related to drought toler ance. Also differences in the effect of drought on seed germination an d seedling growth in 2 field bean and 2 field pea cultivars of differe nt drought tolerances were investigated. The examined cultivars were c haracterized by variation of certain morphological characteristics reg arded as xeromorphic features associated with the ability of plant to survive under drought. The drought resistant cultivars (field bean Gob o and field pea Solara) in comparison with the sensitive ones (field b ean Victor and field pea Bareness) were characterized by more favourab le relations between the size of the above-ground parts and the size o f root, as well as the frequency and size of stomata. Moreover, in the resistant cultivars there was observed, a smaller influence of simula ted drought (Psi = -0.6 MPa) on the increase of dry matter of the abov e-ground parts and of the roots. Also there was smaller influence on t he height of seedlings and on the length of lateral roots. The correla tion coefficients between the measured characteristics and the values of the drought susceptibility index (DSI) were in most cases statistic ally not significant, although, on the whole, they were very high. Thi s may be an indication of a relatively high participation of the measu red characteristics in the total variation of the drought tolerance in the cultivars. In cultivars regarded as belonging to the group of sen sitive ones, a more disadvantageous effect of simulated drought (Psi = -0.6 MPa) on seed germination was observed, especially in the determi nation of the promptness index (PI).