ABSTRACT
El ocumo (Xanthosoma sagittifollium (L.) Schott) es una Arácea cultivada en países tropicales debido al valor nutritivo de sus cormos. La principal limitante para su cultivo es la carencia de semilla de calidad, por esta razón se planteó evaluar la multiplicación de brotes de ocumo blanco en sistemas de inmersión temporal, y el enraizamiento ex vitro de los mismos, para lo cual se estudió el tiempo y la frecuencia de inmersión, y la densidad de explantes sobre la proliferación de los brotes. Asimismo, el efecto del ácido indolacético (AIA) y ácido indolbutírico (AIB) sobre el enraizamiento ex vitro de brotes. De acuerdo con los resultados obtenidos, la mayor eficiencia en la proliferación de brotes se obtuvo utilizando el sistema de inmersión temporal del tipo RITA®, con una frecuencia y tiempo de inmersión de 6 veces/día y 5 min, respectivamente, y una densidad de 9 explantes/RITA®. En el enraizamiento ex vitro se determinó que bajo las condiciones de cultivo empleadas no es necesario el uso de auxinas. Se concluye que es posible la multiplicación eficiente de ocumo blanco en sistemas de inmersión temporal, y realizar el enraizamiento ex vitro sin el uso de auxinas.
The white cocoyam (Xanthosoma sagittifollium (L.) Schott), is an Arácea cultivated in tropical countries, due to the nutritional value of its corms. The main limiting factor for cultivation is the lack of healthy seed, by this reason be outlined to evaluate the multiplication of shoots of white cocoyam in temporary immersion systems and the ex vitro rooting of the same. For that which, itself study, the time and frequency of immersion and the density of explants on the proliferation of the shoots. As well as, the effect of the indole acetic acid (IAA) and indole butyric acid (IBA) on ex vitro rooting the shoots was studied. According to the results obtained, the greater efficiency in the proliferation of shoots was obtained utilizing the temporary immersion system of the type RITA®, with a frequency and time of immersion of 6 times/day and 5 min, respectively and a density of 9 explantes/RITA®. In the ex vitro rooting was determined that under the conditions of employed cultivation is not necessary the use of auxins. It is concluded that is possible the efficient multiplication of white cocoyam in temporary immersion systems and to carry out the ex vitro rooting without the use of auxins.
Subject(s)
Araceae/growth & development , Araceae/adverse effects , Araceae/enzymology , Araceae/physiology , Araceae/genetics , Araceae/immunology , Araceae/microbiology , Araceae/parasitology , Araceae/chemistryABSTRACT
BACKGROUND: We evaluated BacT/ALERT 3D liquid culture system (bioMerieux, USA) and PCR-restriction fragment length polymorphism (RFLP) for recovery and direct identification of mycobacteria, and the results were compared with a conventional culture system using an egg-based solid medium. METHODS: A total of 3,037 bronchial specimens (2,309 bronchial washing fluids and 728 bronchoalveolar lavages) were collected. Decontaminated specimens were inoculated to both BacT/ALERT MP liquid media and Ogawa solid media (3%, Shinyang, Korea). Recovery rate and detection time were compared between the two systems. Liquid media from positive cultures were centrifuged and the pellets were tested for direct identification of mycobacteria by PCR-RFLP using Myco-ID (M&D Inc., Korea). RESULTS: A total of 518 isolates, including 215 M. tuberculosis (MTB) and 303 non-tuberculosis mycobacteria (NTM), were recovered. The liquid media detected 492 isolates (16.2%), including 195 MTB and 297 NTM), whereas the solid media detected 416 isolates (13.7%), including 187 MTB and 229 NTM (P<0.001); 102 isolates (28 MTB and 74 NTM) were recovered only by the liquid media, while 26 (20 MTB and 6 NTM) isolates were recovered only by the solid media. The mean time to detection was 18.1 days by the liquid media and 29.3 days by the solid media (P<0.001). The overall time to species identification from inoculation was 21.8 days. Direct PCR-RFLP from the liquid media identified 39.1% of MTB, 6.3% of M. avium, 19.05 of M. abscessus, and 12.6% of M. intracellulare respectively. CONCLUSION: Combined use of a liquid culture system and PCR-RFLP improved the recovery rate and shortened the detection time. However, solid media is still necessary to maximize the diagnostic efficiency.