Evaluation of drought tolerance in two accessions of smilo grass (Pipthatherum miliaceum L.)

Forage production in Mediterranean environments is limited at the end of spring, when temperatures increase and insufficient rainfall becomes a limiting factor to plant growth. To assess drought tolerance of the native perennial species Pipthatherum miliaceum L., an experiment was carried out on two Sardinian genotypes by inducing a progressive plant water stress at the booting stage of plants. Four water stress levels were applied: no stress, mild, severe and very severe. The following parameters were measured: net photosynthesis (PN), transpiration (E), stomatal conductance (Gs), instantaneous water use efficiency (WUEi) and relative water content of leaves (RWC). Moreover, several morphological traits were compared in plants subjected to different stress levels. The results lead us to hypothesise a specific adaptation response of Pipthatherum miliaceum L. in terms of stomatal conductance and net photosynthesis.