Genetic Control of Rhizome Formation and Tillering Rate in Tall Fescue [Lolium Arundinaceum (Schreb.) Darbysh.].

Tall fescue [Lolium arundenaceum, (Schreb.) Darbysh.] (2n = 42) is a cool season, perennial, self-incompatible, bunch type turfgrass which spreads primarily by erect tillers. It is widely used in athletic fields, home lawns, golf course roughs and sod production; however, its bunch type growth habit can limit its utility. Some genotypes in tall fescue are reported to have short rhizomes and a rapid tillering rate, suggesting that it may be possible to produce tall fescue cultivars with these traits by selective breeding. Tillers improve longevity, turf density, spreading ability, wear tolerance and compactness, while rhizomes increase recuperative ability from damage, help in persistence under drought and temperature extremes, and improve sod strength. Six genotypes were selected on the basis of their growth habit: bunch type, rapid tillering type and rhizome type. Two genotypes were selected for each growth habit. The six genotypes were cross-pollinated in the greenhouse in all possible combinations, using diallel mating design. The mating design was used to assess narrow sense heritability and the general and specific combining abilities of the parental lines. Data was analyzed for number of rhizomes per plant, ground coverage (cm²), and turf vigor. The full-sib progenies from the rhizome parents had the highest number of rhizomes, while full-sib progenies from rapid tillering types with bunch type parents showed significant more ground coverage and turf vigor.