DIFFERENCES IN DROUGHT TOLERANCE BETWEEN CULTIVARS OF FIELD BEAN AND FIELD PEA - A COMPARISON OF DROUGHT-RESISTANT AND DROUGHT-SENSITIVE CULTIVARS

Relatively little research has been conducted to determine different r esponses to drought among cultivars of the legume species. The objecti ve of this study was to identify differences in seedlings growth, wate r relations and leaf conductances resulting from drought imposed on tw o field bean and two field pea cultivars that had been observed to dif fer in their drought tolerances, and special emphasis was placed on th e root system development. Distinct differences between resistant and sensitive cultivars of field bean and field pea became evident in meas urements of the characteristics of the lateral root. The drought treat ment induced statistically significant decrease in the number of the d eveloped laterals, their total length and dry matter. In the drought r esistant cultivars (field bean Gobo and field pea Solara) this reducti on was smaller in comparison with sensitive ones (field bean Victor an d field pea Bareness). The effect of drought on growth of tap root in the drought resistant and drought sensitive cultivars was smaller and statistically not significant. The results showed that drought resista nt cultivars when compared with drought sensitive one would demonstrat e less abundance in the above-ground part and greater dimensions of th e root system. The measurements of leaf water potential and stomata di ffusive resistance measurements indicate that the physiological reason s for the different reactions to drought between the resistant and the sensitive field bean and field pea cultivars may be due to a more eff ective protection of the level of tissue hydration and due to increase stomata diffusive resistance in the resistant cultivars. During recov ery period it has been also demonstrated that in the drought resistant cultivars a tendency exists for a more complete return to the level o f the control plants.