Abstract
Polyploidy breeding plays a key role in agricultural crops such as ryegrasses (Lolium perenne and L. multiflorum), red clover (Trifolium pratense), beet (Beta vulgaris), Brassica spp. and in horticultural crops such as azalea (Rhododendron spp.), roses (Rosa), butterfly bush (Buddleja spp.), Hibiscus spp. and other nursery stock. Polyploidisation can be used in breeding to meet diverse goals: improvement of growth and yield, fertility issues (restoring fertility or introducing sterility), changes in plant morphology or other characteristics like improved stress resistance. Two practical examples of breeding programmes involving polyploids will be discussed: Lolium perenne (perennial ryegrass) and Buddleja.
Polyploidisation of perennial ryegrass is a classical example using colchicine treatment on the meristem in seedlings. Tetraploid grass cultivars have a better digestibility and higher water soluble carbohydrate content and are more palatable to cows than diploid varieties. Moreover they are better resistant against crown rust.
In Buddleja the aim of the breeding programme is the introduction of novel plant types and sterility to avoid invasiveness. In this crop, polyploids were obtained through in vitro chromosome doubling (oryzalin and trifluralin) and by meiotic polyploidisation through unreduced gametes. Interspecific hybridisation was performed in combination with polyploidisation and embryo rescue on plants differing in ploidy levels and genome sizes. Flow cytometry and Genomic In Situ Hybridization (GISH) were used to evaluate the hybrid nature of the plants. The breeding programme yielded sterile triploids and interspecific hybrids.
Polyploidisation of perennial ryegrass is a classical example using colchicine treatment on the meristem in seedlings. Tetraploid grass cultivars have a better digestibility and higher water soluble carbohydrate content and are more palatable to cows than diploid varieties. Moreover they are better resistant against crown rust.
In Buddleja the aim of the breeding programme is the introduction of novel plant types and sterility to avoid invasiveness. In this crop, polyploids were obtained through in vitro chromosome doubling (oryzalin and trifluralin) and by meiotic polyploidisation through unreduced gametes. Interspecific hybridisation was performed in combination with polyploidisation and embryo rescue on plants differing in ploidy levels and genome sizes. Flow cytometry and Genomic In Situ Hybridization (GISH) were used to evaluate the hybrid nature of the plants. The breeding programme yielded sterile triploids and interspecific hybrids.
| Original language | English |
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| Publication status | Published - May-2012 |
| Event | International conference on Polyploidy, Hybridisation and Biodiversity - Pruhonice, Czech Republic Duration: 7-May-2012 → 10-May-2012 |
Conference
| Conference | International conference on Polyploidy, Hybridisation and Biodiversity |
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| Country/Territory | Czech Republic |
| City | Pruhonice |
| Period | 7/05/12 → 10/05/12 |