Festuca apennina – a Future for the ‘Ryegrass of Alpine Pastures’?
Photo: Beat Boller
Widespread in the Swiss alpine region, Festuca apennina could serve as a fodder plant for higher elevations. It also forms vigorous hybrids with meadow fescue and ryegrass. Does this make it suitable for improvement by breeding?
Which fodder plants are suitable for higher elevations where extreme weather conditions and short growing seasons prevail? Back at the beginning of the 20th century, Friedrich Stebler, the first director of the subsequently founded Swiss agricultural research stations, described Festuca apennina (see box) as a potentially valuable fodder plant for the alpine region. Until now, however, its agronomic potential was largely unknown.
We investigated the occurrence of Festuca apennina and its preferences in terms of elevation as well as nutrient and water balance, focusing in particular on the naturally occurring hybrids that it forms with meadow fescue and ryegrass. Comparative field trials at different elevations were carried out to assess the potential of possible breeding activities.
Elevation is key for prevalence
Festuca apennina was found to be widespread in alpine meadows above 1500m.a.s.l., preferring nutrient-rich sites with ample water supply. At intermediate elevations, particularly between 1350 and 1450m, it faces strong competition from naturally occurring hybrids (the products of crossings) of Festuca apennina and meadow fescue (see graph).
Such crossings were also easily created by controlled mutual pollination. In growing trials, the hybrids often grew several times more abundantly than both parent species (heterosis or hybrid-vigour effect). At certain alpine locations, the hybrids were present in downright invasive numbers, due inter alia to a massive clonal spread caused by long rhizomes. Such swards are reminiscent of Italian ryegrass meadows on the Swiss Central Plateau.
Natural crossing with ryegrass
Hybrids of Festuca apennina and ryegrass were also discovered and investigated for the first time. Intergeneric hybrids of this type are termed Festulolium and in breeding terms are deemed to be promising for combining benefits of both genera. The discovered Festulolium hybrids are relatively rare, but they too can spread over more than 100 metres via rhizomes. They are one of the few known examples where Festulolium hybrids occurring without human intervention can establish and thrive in nature.
Sterility as an impediment to propagation
Both hybrid forms are almost completely sterile, i.e. they are non-seed-forming (see box). The indehiscent anthers are the feature by which they are most readily recognisable. To exploit the agronomic potential of these hybrids, ways would have to be found to propagate them. Doubling the number of sets of chromosomes could restore their fertility. Vegetative propagation would also be a promising solution for use in small-scale cultivation niches, e.g. for the remediation of weed-infested animal resting-place patches.
Festuca apennina is on a par with meadow fescue
Twenty accessions of Festuca apennina from nine different mountain cantons were collected, propagated in isolation and their seed stored in the gene bank. Although the plants were inferior to meadow fescue when grown on the Swiss Central Plateau, the best accessions in the growing trial at 1000m.a.s.l. were on a par with recommended varieties of meadow fescue as the trial progressed. Strong dormancy and high seed shedding are traits that would have to be improved in a possible breeding programme. The results of our trials allow the selection of suitable germplasm for this.
Festuca apennina and its relatives Festuca apennina, also called Festuca pratensis var. megalostachys,is closely related to meadow fescue and tall fescue. Festuca apennina has four sets of chromosomes, i.e. it is a tetraploid (4x). It has twice as many sets of chromosomes as meadow fescue, which is a diploid (2x). Two of Festuca apennina’s sets of chromosomes come from meadow fescue, whilst the other two sets stem from an unknown Festuca species. The hybrid forms – both those with meadow fescue and those with ryegrass – are triploid, and hence sterile. |
Conclusions
- Widespread in alpine meadows, Festuca apennina is well adapted to high elevations, where it is on a par with meadow fescue.
- Breeding work seems promising and can focus initially on reducing dormancy.
- Hybrids with meadow fescue are often highly competitive, being markedly more vigorous than the parent species (heterosis or hybrid-vigour effect). Although sterile, they can spread extensively via rhizomes. In pastures at intermediate elevations they can proliferate in an unwanted manner.
- The recently discovered hybrids with ryegrass are fairly rare, but capable of strong vegetative proliferation.
- Vegetative propagation or fertility restoration via chromosome doubling could be used to exploit the enormous potential of the two hybrids.
Bibliographical reference
Potential des Apenninschwingels und seiner Hybriden als Futterpflanzen für hohe Lagen.