Volatile compounds of tufted hairgrass

The primary limitation of tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.] as a turfgrass appears to be damage caused by billbug (Sphenophorus spp.) herbivory. In this study several sets of germplasm were used in volatile collection studies. Whole-plant volatile collections were made on: i) untreated plants, ii) plants that had been treated with jasmonic acid (JA), and iii) plants that had experienced mechanical damage. In untreated plants, intraspecific differences were found for the amount of hexenyl acetate that was released; this compound has been shown to be involved in important plant volatile-insect interactions. Application of JA resulted in a dramatic increase in the production of monoterpenes, which are known to attract predators of insect pests. (Z)-beta-ocimene comprised nearly 9% of the total volatile profile after JA treatment, but was not detected in untreated plants. Mechanical damage of tufted hairgrass plants led to an increased release of characteristic green leaf volatiles such as 3-hexen-1-of as well as hexenyl acetate. Mechanical damage changed the components of the volatile profile, but the results were quite different from JA treatment. It would be of interest to determine if the selection of tufted hairgrass germplasm that produces high and sustained levels of monoterpenes, in response to JA, would attract sufficient insect predators to make this an effective breeding strategy for insect resistance.