Mutation breeding of Chrysanthemum morifolium Ram. using in vivo and in vitro adventitious bud techniques

Abstract

Chrysanthemum morifolium, explants, mutation breeding, adventitious bud technique, chimeral and nonchimeral mutants, in vivo, in vitro, X-rays, solid mutants. SUMMARYDuring experiments, which are being carried out to study the factors which control the process of adventitious bud formation in vivo on detached leaves of Chrysanthemum morifolium RAM, adventitious shoots were produced from leaves, irradiated with 500 rad of X-rays. The most important but disadvantageous result was that the majority of the adventitious shoots proved to be of a chimeral nature and obviously developed from more than one cell.An in vitro adventitious bud technique was developed using different types of explants. Pedicel segments regenerated the highest number of adventitious shoots and, moreover, they developed faster as compared to explants of young flower heads or leaves. The mutants produced by irradiating the various explants were almost exclusively of a solid (non-chimeral) nature. In addition, histological observations suggest that single epidermal cells are involved in the initiation of the adventitious shoot apices.The optimum dose for mutant production is approximately 800 rad X-rays. Rather often, more than one phenotypically identical mutant was found, which was always derived from the same explant. They could for instance originate from a multi-apical meristem formed by a single mutated cell.

Induced Mutations in Ornamental Plants

“…Furthermore, mutation induction often results in chromosomal aberration and consequently obtains mutants with both desirable and undesirable traits. In periclinal chimaeras solely possessing a mutated LI-layer, 'negative' alterations of flower size, plant height, yield etc., are not always expressed (Broertjes et al, 1976).…”

“…Broertjes et al (1976) showed, that plants regenerated via adventitious buds from irradiated in vivo leaves of chrysanthemum cv. Bravo were chimaeras in the majority of cases.…”

Cryopreservation and genetic stability of Dendranthema grandiflora Tzvelev in vitro cultures

“…These variations, which are more or less frequent depending on the cultivar, seem to be related to the fact that many cultivars of chrysanthemum are periclinal chimeras, with one cell layer genetically different to the others (Dowrick andEl-Bayoumi 1965, Martín et al 2002). In the last few years, modern breeding techniques have been incorporated to obtain new cultivars: radiation-induced mutation (Broertjes et al 1976), somaclonal variation induction (Malaure et al1991, Rout andDas 1997) and, more recently, genetic transformation (see review of Teixeira da Silva 2003).…”

Induced changes in growth and flowering of chrysanthemum after irradiation and in vitro culture of pedicels and petal epidermis

“…With mutation breeding for quantitative characters chimera formation is a great problem. BROERTJES et al (1976) showed that in vitro regeneration of adventitious buds from pedicel explants solved that problem.…”