Festuca ovina

Fig. 6. Comparison of the responses of two grasses of contrasted growth rate and morphology to five intensities of shoot impedance, (a) Lolium perenne b) Festuca ovina. Each curve records the mean progress of shoot expansion in five replicate plants subjected to standardised resistances (indicated on each curve as the force in newtons required for initial deflection of weighted windows). Plants were grown individually within a transparent cone, from which the shoots, in order to escape, must deflect windows of standard dimensions and angle of inclination.

Other sand-based systems using COi pulse-chase procedures have been used to produce carbon budgets for Festuca ovina and Plantago lanceolata seedlings (30) and white lupin (Lupimis albiis) (31). Significantly, CO2 pulse labeling of proteoid roots of white lupin under phosphate-deficient conditions showed that high levels of dark fixation of COi by the roots took place and that 66% of this root-fixed carbon was exuded from the roots (31). Clearly, dark fixation of CO2 by roots and subsequent rhizodeposition is an area that deserves further study in the future. 

Fig. 7-14. Relative uptake of 134Cs and 137Cs by two common upland plant species, Festuca ovina and Calluna vulgaris. The solid line in each case is a plot of unity, showing that there is effectively zero discrimination between these two radionuclides during plant uptake (from Mills, previously unpublished).

Alopecurus pratensis, Ammophila arenaria, Arrhenatherum elatior, Dactylis sp., Festuca ovina, F. rubra, Phleurn sp., and Poa pratensis could be naturally colonized by isolates of both Gl and G2. The habitat seems to be more important, as the common occurrence of different groups in the same locality is rare. 

Just as wheat appeared to be tolerant toward diclofop at the whole-plant but not the enzyme level, because of selective inactivation, so various fescue grasses have been shown to be tolerant. At the chloroplast level, the sensitivity of Festuca ovina and F. rubra toward diclofop was comparable to that of the sensitive P. arundinacea The resistance to diclofop in vivo appears to be due to metabolism of the herbicide to less active compounds, as in wheat. By contrast, F. ovina and F. rubra are also resistant to cycloxydim, but, in that case, fatty acid synthesis by isolated chloroplasts is also relatively unaffected (I50 about 100 pM). There may be some differences in the acetyl-CoA carboxylase protein structure in these species that renders cycloxydim binding less effective than usual. 

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