Genetische Variation Des Merkmals Trockentoleranz in Deutschem Weidelgras (lolium Perenne L.) - Evaluierung Phänotypischer Selektionsmerkmale

In the future, global climate change is expected to limit yields in agricultural production due to water shortage in the periods relevant for plant growth. This will also affect perennial ryegrass (Lolium perenne L.), one of the most important grass species in Europe. One of the most promising approaches to overcome this problem is the genetic improvement of drought tolerance by breeding new varieties. In the presented project 200 accessions comprising L. perenne accessions from 20 countries and breeding material as well as some checks from drought tolerant grass species were tested in field trials at drought prone locations. The tested material showed large genetic variation for biomass production under drought conditions. Subsets of this material were tested for drought tolerance under controlled conditions in rain-out shelter, greenhouse and laboratory trials. The subsets of 20 and 50 accessions were used for measuring agronomic performance and detailed phenotyping under controlled drought conditions. Phenotypic traits for a high-throughput recording of drought response of either single plants or plots were tested and compared with yield data. Most of the tested traits showed high heritabilities on a plot as well as on single plant basis and high correlations with yield data were found. The visual scoring of biomass was found to be a suitable selection criteria. In our testset, tetraploid accessions were found to be more drought tolerant than diploid accessions, but drought response seems to be independent from flowering time. Single clones with different drought response could be selected for building segregating populations.