Department of breeding and growing technologies
The Department of breeding and growing technologies deals with breeding methods and their application in breeding new varieties of flowers and woody ornamentals. An important activity in this field also includes the investigation of effective propagation and cultivation methods of woody plants, perennials, balcony flowers and other plants. These methods are used both in the horticultural and nursery sectors for market production of ornamental plants and for the preservation of valuable woody plants from historical gardens and parks and heritage trees, as well as for improving the protection of endangered species and encouraging their return to favourable natural localities. The department is involved with the Czech National Programme on Conservation and Utilization of Plant Genetic Resources and Agro-biodiversity where it ensures the conservation of ornamental plant gene pools.
Main areas of research:
- Breeding of flower plants
- Breeding of rhododendrons
- Generative and vegetative propagation of woody plants
- Growing media and plant nutrition systems
- Conservation and utilization of genetic plant resources
The Institute, as a specialized institution for research in ornamental horticulture, has kept up the tradition of plant breeding since the first half of the last century. The maintenance of several market varieties of annuals, biennials and potted plants has gradually expanded to the research of breeding methods and the creation of new varieties.
Currently, certain varieties of vegetatively propagated petunias (Petunia × atkinsiana) are selected for their resistance to powdery mildew (Sphaerotheca fuliginea), resistance to grey mould (Botrytis cinerea) and types with overhanging habits. Garden chrysanthemums (Chrysanthemum ×grandiflorum) are selected for resistance to septoria leaf spot on chrysanthemums (Septoria chrysanthemella), varieties from the Multiflora group are bred for growing both outdoors and in greenhouses and pot varieties are selected for all year-round culture. Perennial autumn asters (Aster novi-belgii) are selected for their resistance to powdery mildew (Erysiphe cichoracearum var. cichoracearum), frost hardiness, long blooming period and suitability for growing in pots.
Methods of heterosis breeding are used in potted primroses (Primula vulgaris) to produce F1 hybrids with large flowers and a wide range of colours, whose earliness is matching different marketing dates. The varieties of Primula × polyantha have medium-sized “two-corolla” flowers of the hose-in-hose type in decorative inflorescences supported by firm stems, with good frost hardiness as well as resistance to other adverse factors.
Hybridization with subsequent positive selections in the offspring and further propagation of promising individuals is applied to dahlias (Dahlia) and perennials (Hibiscus, Anemone, Echinacea, Lupinus). The objective is to produce lower, more compact varieties with earlier flowering in mostly pastel colours, particularly for growing in containers.
The current breeding program within genus Rhododendron is focused on acceptable resistance to negative biotic and abiotic factors. Hardy genotypes are involved in the stabilization of ecosystems of urban vegetation in relation to changing climate conditions. The next goal of breeding is the search for new and suitable genetic resources of required traits. A collection of extensive assortments collected with the aid of The Czech National Programme on Conservation and Utilization of Plant Genetic Resources and Agro-biodiversity is also very important for breeding of rhododendrons and azaleas. The positive characters of planted genotypes are allowed for breeding purposes due to long term observation and comparison. The most common method in breeding is the intentional crossing between chosen genotypes followed by selection. Primary breeding work dates back to the 1930s in Průhonice. This effort leads to several tens of original Czech cultivars of rhododendrons and azaleas, which are particularly important due to their overall hardiness.
Procedures of generative and vegetative propagation of important and valuable nursery and landscape woody ornamentals have been developed in the institute. These include the preparation of mother plants, terms of harvest, treatment of propagation material, post-harvest treatment of seeds, growth regulators usage for difficultly rooted species in conditions of a controlled microclimate, reliable ways of protection young plants during the winter months, nutritional systems and integrated pests and disease control of container grown trees.
These methods are used for the propagation of valuable genotypes of woody plants of known origin including selected seed trees and heritage trees, rare woody plant taxons and introduced woodies suitable for our continental climate. These are planted on targeted sites such as historic parks or alleys. For fertile broad-leaved trees with germinative seeds, suitable terms of seeds collection, direct sowing or post-harvest seeds treatment is implemented. For infertile tree varieties grafting and budding are applied as the only effective way of their propagation. The research program is focused on the selection of source propagation materials, suitable rootstocks for grafting, optimal propagation terms in controlled growing conditions and production of the plants to the desired sizes and quality.
The use of optimal propagation and growing methods are also part of the salvaging programs of critically endangered species. Nursery stocks of autochthonous species can be used to strengthen the native population in accordance with requirements of the Nature Conservation Agency and administrative authorities of Protected Landscape Areas, and National Parks.
The suitability of various components for preparation of growing media is investigated. Organic components (composts, vermicomposts, separated digestate) are evaluated in respect to their potential for improving physical and chemical properties of organic growing media and the replacement of peat. Mineral components (clay, expanded clay, zeolites, spongilite) are evaluated as amendments improving chemical and physical properties of organic growing media as well as main components of special growing media (green roof substrate, hydroponic substrate). Proposal and evaluations of nutritional systems taking substrate properties, growing technologies and irrigation water quality into account are an integral part of research activity. The chemical and physical properties of growing media are evaluated in the agrochemical laboratory, mostly according to methods recommended by the EU.
This activity is a part of the National Programme on Conservation and Utilization of Plant Genetic Resources and Agro-biodiversity (http://genbank.vurv.cz/genetic/nar_prog/default_a.htm). The aim is to conserve the varieties (and/or species) of ornamental plants which represent a significant genetic potential. More than 1700 taxons of the groups of ornamental plants listed below are preserved (conserved):
- rhododendrons (Rhododendron)
- ornamental apple-trees (Malus)
- original native varieties of roses (Rosa)
- bulbous and tuberous plants (Tulipa, Gladiolus, Dahlia)
- generatively propagated flower species (annuals, biennials, greenhouse plants)
- vegetatively propagated flower species (annuals, cascading petunias, chrysanthemums)
The collection of genetic resources is based on a general principle to conserve mainly domestic assortments. Subsequently, the particular items are described by means of defined descriptor lists and recorded in the EVIGEZ information system: http://genbank.vurv.cz/genetic/resources/asp2/default_c.htm
Regeneration is applied in accordance with approved methodology while, in addition, the seed of generatively propagated species is stored in the gene bank at –18° C. Distribution of samples to users is carried out upon written request.