turfgrass

Grasses

Poaceae, the grass family, includes some 12,000 species in 700 genera. Of these, 37 species plus interspecific hybrids, in 18 genera, have suitable growth habit to have been developed as turfgrasses.

The 18 genera of turfgrasses are in 7 of the 28 grass tribes, 4 warm-season tribes, Andropogoneae (Bothriochloa, Eremochloa); Cynodonteae (Bouteloua, Buchloe, Cynodon, and Zoysia); Eragrostideae (Dactyloctenium); Paniceae (Axonopus, Digitaria, Paspalum, Pennisetum, Stenotaphrum) and 3 cool-season tribes, Aveneae (Agrostis); Poeae (Festuca, Lolium, Poa, Puccinellia); and Triceae (Agropyron).

Warm-season turfgrasses such as bermudagrass, Cynodon dactylon, are C4 plant species which are well adapted to hot dry climates by physically separating the initial carbon fixation from carbon dioxide (CO2) in a 4-carbon molecule in mesophyll cells, which diffuses to specialized bundle-sheath cells for sugar production by the Calvin Cycle.

Cool-season grasses such as Kentucky bluegrass, Poa pratensis and tall fescue, Lolium arundinaceum, are C3 plant species with no physical separation of carbon fixation (in an initial 3-carbon molecule) from the Calvin Cycle that produces sugars. The C4 vs. C3 metabolic distinction is correlated with adaptive differences in other characteristics such as adaptation to warm vs. cool climates and susceptibility to insects and diseases.

Turfgrass breeders use traditional methods of hybridization and progeny selection, transgenesis (GMO), and discovery within natural occurring populations to find improved genotypes of turfgrass with resistance to biotic and environmental stresses and acceptable performance in appearance and play. Thousands of cultivars or trade types have resulted.