Comparative Characteristics of Newly Developed Perennial Ryegrass Varieties in Bulgaria

Abstract

Three new varieties of perennial ryegrass were developed during the period 1995–2015 in the Institute of Forage Crops in Pleven, Bulgaria. Different breeding methods were applied to develop these varieties. After individual phenotypic selection, a polycross of 91 elite diploid genotypes with local origin was applied for the creation of the variety IFK Harmoniya. The varieties Tetrany and Tetramis were developed by polyploidization of local breeding populations, flowcytometric screening and phenotypic selection, followed by a polycross of 45 and 52 tetraploid elite genotypes. IFK Harmoniya was the first diploid variety registered on the Official Variety List of the Republic of Bulgaria in 2010. The two tetraploid candivars follow the national official variety testing trials for Value of Cultivation and Use (VCU) in three locations and for Distinctness, Uniformity and Stability (DUS) in one location, organized by the Executive Agency for Variety Testing, Field Inspection and Seed Control since 2014. IFK Harmoniya is an early diploid, highly productive, ecologically stable (winter hardy and drought tolerant), persistent, multifunctional perennial ryegrass variety with a dense sward, suitable for pasture, hay-pasture and amenity, in pure stands or in mixtures with white clover for forage or with red fescue for ornamental and sports fields. If Tetrany passes the VCU and DUS trials, it will be the first Bulgarian tetraploid perennial ryegrass variety: it is an early to intermediate heading, persistent, winter hardy, drought tolerant, crown rust-resistant, highly productive and leafy candivar with a good feeding value. Tetramis is a tetraploid, very early, persistent, winter hardy, drought tolerant perennial ryegrass candivar that combines a good resistance to crown rust with a high production of forage biomass and seed.