Maurecilne Lemes da Silva

Morfoanatomia dos sistemas gemíferos de poaia (Carapichea ipecacuanha (Brot.) L. Andersson) – Rubiaceae

Carapichea ipecacuanha is a sub-shrub species known as “poaia” or Ipecac, widely used as therapy for healing and amoebiasis, attributed to emetic alkaloids. This work was undertaken to describe the main aspects of the vegetative reproduction and ontogeny of root-derived adventitious buds. In nature, the regeneration of this species is essentially carried out from root sprouts. Variation on the stem external morphology was observed which encloses subterranean parts (straight or horizontal to soil) and aerial parts that, in general, bend to the soil surface, where adventitious roots are emitted from the internode.. Root fragments of C. ipecacuanha were placed in distilled water (with and without 8.9 µM 6-benzyladenine - BA) and in hydroponics medium with Hoagland solution (with and without 8.9 µM BA). Adventitious buds developed from the phellogen, whose cells divided in several planes, generating the neoformed meristemoids. The buds were formed asynchronously on the surface of roots that presented secondary growth. The bud vascular system was formed mainly by differentiating meristematic cells, and with a late development it was entirely connected to the root vascular system.

Cytogenetic characterization of Encyclia caximboensis cultivated in vitro (Orchidaceae).

Encyclia caximboensis is an Amazonian species endemic to the Serra do Cachimbo, which is located between the northern of the Mato Grosso state and the southern part of Para state. Studies reporting in vitro cultivation and cytogenetic characterization of this species are still scarce. Therefore, the objective of this work was to determine the cytogenetic characteristics and to identify the nucleolar organizer regions (NORs) of the species E. Caximboensis, cultivated in vitro. Seeds of E. caximboensis were disinfected using a syringe and subsequently cultivated in MS medium without growth regulators. The germination started after 20 days of culture, with the development of protocorm and 40,500 seedlings were obtained after 90 days of culture. To perform the cytogenetic solution, 3:1 (v/v) and the slides were stained using 5% Giemsa solution. Ag-NOR banding was carried out on 20-day-old slides by incubation in 50% silver nitrate solution (AgNO3 ) for 19 hours. The results indicated that E. caximboensis has 2n=2x=24 with all metacentric type chromosomes, ranging from 1.88 to 0.66 µm in length, with simple NORs in small blocks localized in the proximal region of the third chromosome pair

Morphoanatomy of Shoot-Bud Forming Root Systems of Poaia (Carapichea ipecacuanha(Brot.) L. Andersson) - Rubiaceae

The aim of the present work was to describe the principal aspects of the vegetative reproduction and ontogeny of the gemmifer system of C. ipecacuanha. Vegetative propagation takes place during the rainy season between November and March. Under natural conditions adventitious buds are formed on roots from parental plant, on stem regions or from isolated radicular segments that suffered mechanical injuries. Root-derived adventitious buds during secondary growth stage present typical structure, with wide cortex bearing successive phellogens originated from cell division of epidermal and sub-epidermal layers. On the region where adventitious roots are formed successive phellogens and suber located internally to the collenchyma, and after their emergence are successively peeled-off. Root fragments of C. ipecacuanha cultivated in Hoagland hydroponic solution and distilled water, non-supplemented and supplemented with 8.9 μM of BA developed sprouts, with an average of 12.5. Adventitious buds differentiate in meristemoids originated from phellogen. Development of apical meristem of the radicular buds causes the breaking out of the peridermal layers while buds s with early leaf under differentiation on root surface become visible. Shoot-buds are located on root periphery region under secondary growth, presenting asynchronous development in the same segment.