Drought and high temperature resistance evaluation of Dactylis glomerata L.

With the aim to identify cultivars characterized by high drought and temperature resistance and
high water use efficiency a study was carried out on 1 accession (Jana) and 4 Sardinian ecotypes of orchard
grass (Dactylis glomerata L.) (Bolotana, Bonorva, Bonnanaro, Platamona). To evaluate the adaptive responses
of different D. glomerata ecotypes, two trials were carried out in order to evaluate drought resistance under
rain proof shelter and controlled water supply, and to evaluate high temperature resistance in a greenhouse
where high summer temperature (daily maximum temperature > 50 °C) were monitored. On December 2010
seeds were sown in seed benches at the beginning of March the plants were transplanted at the 5th leaf
stage in 45 litres pots, utilized in the drought resistance trial, and in a container (25 x 0.8 m), utilized in the
high temperature resistance trial. In drought resistance trial, two water regimes were applied: 1) Control, soil
humidity was kept at the field capacity, 2) W1, pots water losses were reintegrated at 80%. Above ground
plant biomass, net photosynthesis, transpiration rate, stomatal conductance, leaf relative water content
(RWC) were monitored throughout both trials.