Resumo As cultivares de Kalanchoë são consideradas uma das plantas ornamentais em vasos mais vendidas do mundo. Entre suas principais características que sustentam o grande interesse do mercado estão o longo período de floração, abundância de flores, folhas grossas e brilhantes, fácil manutenção e menor necessidade de água em comparação com outras plantas em vasos. Nos estudos de melhoramento de Kalanchoë, plantas com diferentes cores de flores como branco, creme, amarelo, laranja, vermelho, rosa e roxo foram desenvolvidas. Além disso, também foram obtidas cultivares com flores duplas (com grande número de pétalas), mais compactas e cultivares com flores maiores. Características morfológicas inovadoras estão sempre em alta demanda no mercado de plantas ornamentais. O aumento da variação no pool gênico com espécies diferentes desempenhou um papel importante no desenvolvimento dessas características. Hoje em dia, não apenas as cultivares em vasos são lançadas, mas também as cultivares de flores de corte foram desenvolvidas e apresentadas aos consumidores. Além do melhoramento convencional e da hibridização interespecífica, métodos biotecnológicos, de futuro promissor, são utilizados para desenvolver características morfológicas de Kalanchoë.

Abstract Kalanchoë cultivars rank as one of the most sold potted ornamental plants in the world. Among its key features that sustain high market interest are the long flowering period, abundance of flowers, thick and glossy leaves, easy maintenance and less water requirement compared to other potted plants. In breeding studies of Kalanchoë, plants with different flower colors such as white, cream, yellow, orange, red, pink and purple were developed. Moreover, double-flowered cultivars (comprising a large number of petals), more compact and cultivars with larger flowers were also obtained. Novel morphological characteristics are always in high demand in the market of ornamental plants. Increasing the variation in the gene pool with different species played a major role in the development of these characteristics. Nowadays, not only potted cultivars are launched but also cut flower cultivars have been developed and presented to consumers. Besides conventional breeding and interspecific hybridization, biotechnological methods, which have a promising future, are used to develop morphological characteristics of Kalanchoë.

ABSTRACT Rhodiola rosea L. is an endangered medicinal plant distributed in mountains and in high latitude regions. For its conservation, sustainable methods for the obtaining of its bioactive compounds must be developed. This work hypothesized that leaf, stem and rhizome explants of R. rosea from different geographical origins respond differently to inoculation with Rhizobium rhizogenes agropine strain ATCC43057. The objective was to generate R. rosea hairy roots (HRs) containing rol-genes. These HRs could be cultivated under axenic conditions for the extraction of the medical compounds rosavinoids and salidroside. Hereby, production of bioactive compounds could be improved per plant biomass. Thirteen R. rosea accessions of Alpine, Scandinavian, Nordic Gene Bank (NGB) and Russian origins were compared for their explant survival and HR formation. Significant differences were observed among plants from different geographical origins, where the NGB leaf explants exhibited up to 70% of HR formation and the Russian accessions did not exhibit HRs at all. Moreover, maintaining explants in light conditions after R. rhizogenes inoculation resulted in higher explant survival and HR formation rate (35%) when compared with explants kept in darkness (9%). Taken together, an efficient HR formation in roseroot by inoculation of R. rhizogenes following culturing in light was reported as a required step. This work represents a stepping-stone to R. rosea HR cultivation in bioreactors as well as regenerating whole plants. Hence, it is initiating a novel route towards high-throughput production of bioactive compounds as well preventing depletion of natural roseroot populations.

RESUMO A origem da galha-da-coroa, a bactéria Agrobacterium tumefaciens foi isolada há 100 anos atrás. Setenta anos depois, a descoberta da integração aleatória do DNA bacteriano no genoma da planta hospedeira permitiu a exploração do potencial desta bactéria como ferramenta de engenharia genética de plantas. Desde os anos 80, desenvolveu-se rapidamente a transformação de uma vasta gama de espécies mediada por Agrobacterium. Esta revisão é focada nos oncogenes da A. rhizogenes que é o agente causal da síndrome da raíz de cabeleira e suas aplicações agronômicas.

ABSTRACT The bacterial origin of crown gall tumours, Agrobacterium tumefaciens was isolated 100 years ago. 70 years later, the findings that random integration of bacterial DNA into the host plant genome provided the potential of using Agrobacterium as a plant genetic engineering tool. Since the 1980s, Agrobacterium-mediated transformation on wide range of plants began developing rapidly. This review focused on the oncogenes of A. rhizogenes which is the causative agent of the hairy root disease and the application of A.rhizogenes in plant science.