Abstract

The Czech national core collection of the red clover (Trifolium pratense L.) was established in 2006 based on previous analyses (2004 to 2005) of morphological and some phytopathological data observed in the field conditions. Input set included 57 tetraploid accessions (varieties and newly bred varieties) and 130 diploid accessions (varieties, newly bred varieties and wild forms collected from nature) of the world collection. The core collection includes 76 accessions. Molecular and phytopathological data on the core collection were obtained after its establishment during 2007. The core collection was from the point of view of resistance to important fungal and viral pathogens evaluated. Tested plants were inoculated by spore-suspension of Fusarium sp. fungi and also by Bean yellow mosaic virus (BYMV). Microsatellites (SSRs) were used for the study of genetic diversity of all the core collections accessions. No clear difference between diploid and tetraploid accessions within the core collection was evidenced by cluster analysis of morphological data. Notable correlation was found only between the seed weight and ploidy level. The relationships among accessions were analysed with hierarchical clustering, separately for the morphological data (50 characters) and the data on SSR polymorphism (11 primers, 23 polymorphic bands). Molecular and morphological data were not significantly correlated. No differences in particular morphological characters were observed to be associated with the presence/absence of particular bands or with the overall pattern of SSR polymorphism. Dendrogram of accessions included into the Czech core collection of the red clover based on morphological data showed separation of items into seven subclusters, while dendrogram based on molecular data showed the separation of items into 13 subclusters. The core collection accessions showed some level of resistance to Fusarium sp. and BYMV infection. The correlation between resistance of core collection accessions to Fusarium sp. and BYMV pathogens was not significant.

Key words: Red clover, core collection, genetic diversity, ploidy level, microsatellites, morphological characteristics, Fusarium sp., BYMV.