Other subgenera of Festuca also are very important as pasture in Europe and as turf worldwide. Yet, compared to subg. Schedonorus and Lolium, many fewer hybrid breeding and cytologenetic analyses have been done to elucidate relationships among other species of Festuca. Malik and Thomas (1966) provided one of the more comprehensive karyotype studies, in which they examined seven Lolium species and 17 species and subspecies of Festuca. Included were representatives of sections Ovinae [Festuca hervieri Patzke (= F. ovina subsp. laevis Hack.) and Festuca rupicola Heuff. (= Festuca ovina subsp. sulcata Hack.) (both diploid, with 2n = 2x = 14), F. ovina L. (tetraploid, with 2n = 4x = 28), Festuca polesica Zapal. (2x = 14), F. ampla Hack., and F. rubra L. (both either 6x = 42 or 8x = 56)], Montanae [F. donax Lawe and F. altissima All. (both 2x = 14)], Scariosae [F. sclerophylla Boiss. ex Bisch. (6x = 42)], Bovinae [F. mairei (4x = 28)], Subbulbosae [F. spadicea L. (2x = 14 or 4x = 28)], and Variae [F. albida Lawe (4x = 28)].

Polyploidy has played an obvious role in at least five of the six sections within the genus Festuca, accounting for approximately 74% of all Festuca species. Ploidy levels can be very high within the genus, extending upward to decaploids in sections Bovinae and Ovinae. High levels of polyploidy, together with a wide geographical distribution, suggest that the genus is quite old.

Borrill et al. (1977) analyzed several diploid Festuca species in a search for a potential second diploid ancestor to the two allotetraploids discussed above, 4x F. arundinaceum and F. mairei. As it is fairly well established that L. pratense is one progenitor to 4x F. arundinaceum, as F. scariosa is to L. mairei, they examined the crossablility of these two known progenitors with other Festuca diploids in sections Montanae (F. donax, F. drymeja Mert. and Koch, and F. altissima), and Ovinae (F. polesica). Hybrids obtained from these crosses were analyzed further for fertility and efficiency of chromosome pairing. They found that all three grasses in section Montanae were interfertile with each other, and F. donax and F. drymeja were so closely related that they might be regarded as a single biological species. Both of these grasses formed hybrids with F. altissima, but fertility often was affected, suggesting more genetic distance from F. donax and F. drymeja. All three of these Montanae diploids were crossed successfully with F. scariosa, but chromosome pairing was reduced in the resulting hybrid plants. The greatest effect on offspring fertility was in the cross with F. drymeja, suggesting considerable differences between chromosome sets of these species. In contrast, crosses attempted between F. drymeja and L. pratense were almost always unsuccessful. The hybrid plants that were generated were male sterile with extensive failure in chromosome pairing. This indicates a high degree of reproductive isolation between L. pratense and section Montanae. Attempted crosses between L. pratense and F. scariosa and between either of these and F. polesica (section Ovinae) were largely unsuccessful. From these results, Borrill et al. (1977) suggested that two "diploid species-clusters" can be discriminated: one including F. scariosa, F. donax, F. drymeja, and F. altissima (with spp. drymeja and donax belonging to the same biological species), and the other including L. pratense, L. perenne, and L. multiflorum. These relationships were supported further by the recent molecular phylogenetic analysis of Torrecilla and Catalán (2002).

<--Previous         Next-->