Evaluation of wild red clover (Trifolium pratense L.) ecotypes and hybrid populations (Trifolium pratense L. × Trifolium diffusum Ehrh.) for clover rot resistance (Sclerotinia trifoliorum Erikss.)

Abstract

Forage grass breeders are intensively searching for qualitatively novel initial breeding material, more attention is being paid to wild ecotypes’ phenomenon of polymorphism within the species, and the application of interspecific hybridisation is becoming increasingly widespread. The present study was designed to investigate the variability of clover rot resistance (Sclerotinia trifoliorum Erikss.) in wild red clover (Trifolium pratense L.) ecotypes and hybrid populations (Trifolium pratense L. x Trifolium diffusum Ehrh.). Red clover ecotypes were found to possess a different resistance to the clover rot causal agent: 38.5% of the ecotypes were attributed to the moderately resistant clover group, whereas the plants of the standard variety ‘Liepsna’ were found to be non-resistant. Compared with non-resistant ecotypes, moderately resistant wild ecotypes exhibited a better overwinter survival and better digestibility characteristics, however, they accumulated lower contents of crude protein and green material. Interspecific hybrids, compared with the plants of the standard varieties ‘Liepsna’ and ‘Vyliai’, were characterised by increased (on average 1.4 times higher) resistance to the causal agent of clover rot. Keywords: resistance, red clover, wild ecotypes, Trifolium pratense L. × Τrifolium diffusum Ehrh., Sclerotinia trifoliorum Erikss