Title : Abiotic stress tolerance in perennial grasses recommended for the management of dry and degradated areas.
Abstract:
Permanent grassland are a source of healthy forage for a large group of ruminant animals. They also serve to conserve biodiversity, reduce environmental pollution, including nitrogen oxide and sulfur in the air. They can contribute to the agro ecosystem sustainability by reducing soil erosion and conserving soil water. Ecotypes may provide genetic resources to improve resistance / tolerance for water stress limit or different soil type. Water conservation is the responsibility of every citizen, not just in areas with drought or low moisture conditions. Drought resistance is being increasingly labelled as being a ‘complex trait’. There are two different opinions regarding the impact of agricultural intensification on biodiversity. Some authors suggest that is that caused the extinction of many ecotypes and replacing them with new forms of crops. According to other authors the negative impact on the biodiversity is not observed, because the genetic resources in situ and ex situ form are included into the breeding programs and the wide variation within the newly created varieties could be maintained.
In the resent study as a plant material ecotypes and commercial hybrid which belong to 7 cool-season grass species were used: tall fescue (Festuca arundinacea), meadow fescue (Festuca pratensis Huds.), red fescue (Festuca rubra L.), perennial ryegrass (Lolium perenne L.), Timothy-grass (Phleum pratense), Kentucky bluegrass (Poa pratensis) and Deschampsia cespitosa. Ecotypes were collected from semi-natural area representing different part of Poland. Next, based on the preliminary description, 15 – 17 genotypes which represent each species, were included into recent study. For the greenhouse test seedlings were taken from the experiment conducted under field conditions and after vegetative propagation they were planted into pots. Tolerance to different soil type: tree treatments – (1) soil with low phosphorus, magnesium n-organic, C-organic content, (2) soil with high clay content and low phosphorus and magnesium content, (3) control (mixture: 3 peat : 1 sand). ). Plants were cut every 7 days at a height 7 cm (red fescue - 4 cm), and regrowth measured. Tolerance to water deficit test: plants grow for six weeks at an optimum moisture content of the soil (35 – 42%; soil type - mixture: 3 peat : 1 sand), cut every 7 days at a height 7 cm (red fescue - 4 cm), and regrowth measured. After this time resistance for water deficit and different type of soil was evaluated.
Different type of soil test was conducted in three treatments: control (mixture: 3 peat : 1 sand) and two types of soil taken from devastated area. Based on the results obtained in the water deficit test it was possible to conclude, that differences for red fescue, tall fescue and Deschamsia caespitosa regrowth under drought stress and under control conditions were not significant.
