BREEDING AND DEVELOPMENT OF ‘ALEXA II,’ ‘BLUECHIP PLUS,’ ‘FRONT PAGE,’ ‘GINNEY II,’ AND ‘NUBLUE PLUS’ KENTUCKY BLUEGRASS (POA PRATENSIS L.)

摘要

Kentucky bluegrass (Poa pratensis L.) is an aggressive sodforming grass,useful as amenity turf,sports turf,or for animal grazing.It is typically grown in multiple-cultivar blends for golf course,sports field,lawn,and landscape surfaces.This article describes the breeding and development of five cultivars,all sharing a common trait of low mowing height tolerance.Alexa II,BlueChip Plus,Front Page,Ginney II,and NuBlue Plus are seed-propagated single-clone apomictic cultivars with minor but measurable differences in morphology.All five cultivars trace back through generations to ‘Midnight’ Kentucky bluegrass,which was a top scoring cultivar in US national tests.All are classified as medium-late to very late in reproductive maturity.All have shown improved resistance to dollar spot (caused by Sclerotinia homoeocarpa F.T.Bennett),warm-weather brown patch (caused by Rhizoctonia solani Kühn),and summer patch (caused by Magnaporthe poae Landschoot & Jackson).Alexa II,BlueChip Plus,Front Page,Ginney II,and NuBlue Plus are recommended for golf course tees,fairways,and roughs,and for lawns,parks,and sports turf,in full sun or partial shade,in areas where Kentucky bluegrass is well adapted for turf.They are compatible in blends and mixtures with other cool-season turfgrasses at mowing heights as low as 13 mm.