ROOT CONTRIBUTION TO WATER RELATIONS AND SHOOT IN TWO CONTRASTING VIGNA UNGUICULATA CULTIVARS SUBJECTED TO WATER DEFICIT AND INOCULATION

This study aimed to investigate if root exercises influence on water relations and shoot of Vigna unguiculata plants exposed to combined action of water deficit and inoculation. The experimental design used was completely randomised with 2 cultivars (tolerant and sensitive) combined with 2 water regimes (water deficit and control), and 2 inoculation forms (inoculated and non-inoculated), totalising 8 treatments. Parameters evaluated were leaf relative water content, stomatal conductance, transpiration rate, leaf dry matter, stem dry matter, and root dry matter. Stomatal conductance was reduced in plants exposed to water deficiency in tolerant and sensitive cultivars, but plants inoculated presented no significant difference, when compared with non-inoculated plants. Water deficit provoked decrease in root dry matter of both cultivars, comparing to control plants, while tolerant plants exposed to water deficiency presented better results, if compared with sensitive plants. Significant relationships between root dry matter and stomatal conductance, as well as root dry matter and shoot (leaf and stem) were found in this study, confirming the hypothesis on influence of roots on water relations and shoot.