Breeding perennial ryegrass (Lolium perenne L.) for turf usage: an assessment of genetic improvements in cultivars released in Europe, 1974–2004

Abstract

An assessment of genetic improvement in turf‐type perennial ryegrass was performed at a network of six locations. A comparison was made of the turf performances of five natural populations, five forage‐type cultivars used for turf seeding until the 1980s and 31 turf‐type cultivars released from 1974 to 2004. Populations and cultivars were also compared in two spaced‐plant experiments and in two seed‐yield trials. Trait regressions on registration year of turf‐type cultivars showed that breeding had been highly successful in improving the turf aesthetic merit (from +8·8 to +12·5% per decade according to seasons), wear tolerance (+5·4% per decade) and crown‐rust resistance (+8·9% per decade) and in lessening the turf height increase rate (−0·43 mm day−1 per decade). Turf winter greenness had been marginally improved, whereas summer greenness and seed yield had not been significantly changed. A multivariate analysis provided evidence that turf density and fineness played a major role in the visual assessment of turf aesthetic merit and that wear tolerance was closely associated with turf density. Conflicting trait associations may have precluded improvements in turf ground‐cover 3 months after sowing, turf winter greenness and turf persistency.

Natural diversity in vegetative and reproductive investments of perennial ryegrass is shaped by the climate at the place of origin

“…The genetic variability (adjusted means per genotype) was very high for all traits (Table 3). We observed a fourfold difference between genotypes, which is much higher than reported by Sampoux et al (2013), who found that leaf length varied between 25 and 40 cm (a 1.6-fold difference between genotypes) between turf and forage cultivars.…”

Pleistocene climate changes, and not agricultural spread, accounts for range expansion and admixture in the dominant grassland species Lolium perenne L.

“…Recurrent selection in plant breeding germplasm has so far resulted in the release of more than 1,000 L. perenne cultivars improved for forage production (European Commission, ). More recently, since the 1960s, similar selection methods have also been implemented to release L. perenne cultivars improved for turf usage (Sampoux et al, ). We genotyped 32 cultivars representing a large diversity of the L. perenne cultivars bred for forage usage in various countries of Europe and New Zealand.…”

Drought tolerance in perennial ryegrass (Lolium perenne L.) as assessed by two contrasting phenotyping systems

“…The predicted rise in atmospheric temperature can be expected to intensify both the frequency and severity of heat waves, drought and flooding (Jacob et al, 2013;Trnka, Hlavinka, & Semenov, 2015). The future productivity of perennial ryegrass (Lolium perenne L.; Lp), presently among the most widely grown grass species in temperate zones (Sampoux et al, 2011(Sampoux et al, , 2013, will be compromised by drought, as-unlike many grass species-it forms a rather shallow rooting habit, limiting its inherent level of drought tolerance (Sheffer, Dunn, & Minner, 1987). As irrigation is generally not an economically viable option for pasture land, there is a need to breed more drought tolerant varieties (Lobell & Gourdji, 2012), unless the choice is to abandon the species for other, more drought tolerant grasses.…”