PL
Chryzantema wielkokwiatowa zaliczana jest do najbardziej popularnych roślin ozdobnych na rynku ogrodniczym. Światowa produkcja tego gatunku rośnie z każdym rokiem. Skomplikowana biologia chryzantemy (wysoki poziom ploidalności, heterozygotyczność, poligeniczna kontrola kwitnienia, samoniezgodność oraz ograniczona żywotność pyłku) ogranicza jednak skuteczność tradycyjnych metod hodowlanych (krzyżowanie i selekcję). Dzisiaj, aby zaspokoić rosnące wymogi rynku w hodowli i rozmnażaniu tego gatunku, stosuje się nowoczesne osiągnięcia biotechnologii. W celu pozyskiwania nowych odmian wykorzystuje się hodowlę mutacyjną. W jej efekcie często uzyskuje się jednak chimery. Organizmy takie wymagają opracowania szczególnych warunków rozmnażania i przechowywania. Ostatnie dekady przyniosły jednak znaczący postęp w zakresie wykorzystania kultur tkankowych w reprodukcji chryzantemy. Celem niniejszej pracy jest przedstawienie wybranych zagadnień z zakresu biologii oraz nowoczesnych metod hodowli i reprodukcji chryzantemy wielkokwiatowej.
EN
Due to a great variety of flower shapes and colours, chrysanthemum is one of the most popular ornamental plants. It is expected that in the future chrysanthemum may become the number one product on the market. However, a complicated biology of the species; high ploidy and heterozygosis, polygenic control of flowering, self-incompatibility and limited pollen viability, reduces the efficiency of traditional breeding methods (selection and crossing), popular in the 19th century when they allowed for the production of dozens of cultivars. Today, in order to meet the growing demands of the market, modern biotechnology tools are applied. Mutation breeding (with the use of physical agents: 5–30 Gy X or gamma irradiation mainly) are commonly used since the 1960s. The technique facilitates a fast and low-cost production of new cultivars; with changed flower colour, leaf shape or the entire plant architecture being altered. The most efficient cultivars used as a source of explants for mutation breeding are those of purple flowers, while the least – the yellow-blooming ones. As a results of induced or spontaneous mutations, however, genetically unstable chimeras are often regenerated, if the mutation is present only in the part of the meristem. Such organisms require particular consideration while developing protocols for their storage and propagation, since they are vulnerable for the separation of chimerical components. The recent decades have brought a significant progress in the application of tissue culture in chrysanthemum reproduction and breeding. In vitro cultivation of chrysanthemum was first developed in the 20th century and used for eliminating viruses and other pathogens. For this purpose meristem cultures have been still applied. The most popular application of tissue cultures, however, is micropropagation. As for chrysanthemum, various explant types were used for multiplication; roots, leaves, nodes, internodes and flowers. In general, stem explants are more efficient than leaves in terms of the multiplication rate, while flowers are more susceptible to the occurrence of somaclonal variation. Explants with meristems, usually single-node fragments, are used for vegetative multiplications of periclinal chimeras since only then can their stability be maintained. Other techniques; adventitious organogenesis and somatic embryogenesis, are more efficient, as based on the concept of plant totipotency, however, they are more threatened with somaclonal variation occurrence and have a limited use with commercial propagation of chimeras. Still they are very useful in both mutation and transgenic breeding at the stage of regeneration. To stimulate regeneration cytokinins, usually benzyladenine, and various auxins, in lower concentrations, are applied. The aim of this paper is to present selected aspects of biology and modern methods of breeding and reproduction in chrysanthemum.