ABSTRACT
ABSTRACT The preservation of banana genetic material is usually performed through seedlings. However, most banana cultivars do not produce seed and are propagated vegetatively. Therefore, cryopreservation is a feasible technique that allows the preservation of banana genotypes indefinitely. For the success of cryopreservation protocols, the selection of cryoprotectants and pre-freezing techniques are important factor. Therefore, the objective of this study was to verify the effects of different cryoprotectants with and without 1% phloroglucinol and pre-cooling periods on the development of a protocol for cryopreservation of in vitro rhizomes ofMusa accuminata(AAA) cv Grand Naine banana. The addition of 1% phloroglucinol to the cryoprotective solutions, such as PVS2 enhanced recovery of cryopreserved banana rhizomes. In addition, pre-cooling of explants in ice for 3 hours in PVS2 + 1% of phloroglucinol allowed efficient cryopreservation of banana rhizomes, followed by successful recovery and regeneration of in vitro shoots of banana cv Grand Naine.
Subject(s)
Phloroglucinol/pharmacology , Cryopreservation/methods , Cryoprotective Agents/pharmacology , Musa/cytology , Rhizome/cytology , Reference Values , Sucrose/pharmacology , Time Factors , Reproducibility of Results , Plant Shoots/drug effects , Plant Shoots/physiology , Musa/drug effects , Rhizome/drug effects , Glycerol/pharmacologyABSTRACT
La conservación in vitro de Dioscorea alata L. clon Caraqueño es fundamental para garantizar la propagación y distribución de material de plantación sano a los productores, y disponer de un banco in vitro de un clon de gran valor agronómico y comercial en la región oriental de Cuba. Con el fin de evaluar las modificaciones anatómicas que se producen en plantas de ñame en tres condiciones de cultivo in vitro: plantas conservadas por métodos de mínimo crecimiento, plantas regeneradas y plantas en fase de multiplicación en el medio MS 75 %, se realizó un análisis de la anatomía foliar y caulinar a partir de cortes transversales de la lámina foliar y del tallo, y cortes longitudinales y transversales de microtubérculos formados durante el proceso de conservación. Las hojas de las plantas conservadas mostraron menor espesor del mesófilo y la epidermis y el área de los haces conductores del tallo también fue menor, debido al proceso de stress durante la conservación in vitro. Sin embargo, durante la recuperación del material conservado a través de la regeneración y la multiplicación in vitro se restablecieron de manera normal estos parámetros. También se evidenció que los microtubérculos formados en la conservación in vitro, poseen parénquima amilífero con abundantes gránulos de almidón, capa delgada de parénquima cortical, y haces conductores poco desarrollados, todo lo cual indica la presencia de actividad meristemática.
The in vitro conservation of Dioscorea alata L. clone Caraqueño is fundamental to guarantee the propagation and distribution of healthy plantation material to the farmers and the establishment of one in vitro bank of this clone of great agronomic and commercial value in the Oriental Region of Cuba. With the purpose of evaluating the anatomical modifications that take place in yam plants under three in vitro culture conditions: conserved plants by slow growth, regenerated plants and in plants multiplication phase in MS 75% medium, was carried out an analysis of the foliar and caulinar anatomy from transversal cuts of the foliar sheet and of the stem, and longitudinal and transversal cuts of microtubers formed during the conservation process. Smaller thickness of the mesophyll and of the epidermis in the leaves of the conserved plants were showed and the conductive sheaves area of the stem were also smaller, due to the stress process during the in vitro conservation. However during the recovery of the conserved material through the regeneration and the in vitro multiplication were reestablished to their normal state these parameters. It was also evidenced that the microtubers formed in the in vitro conservation, have reserve parenchyma with abundant starch granules, thin cortical parenchyma and conductive sheaves little developed were determined. All this characteristics indicated the presence of meristematic activity.
ABSTRACT
Cochlospermum regium é uma planta de áreas de cerrado, caatinga e pantanal. Na medicina popular é conhecida por "algodão-do-campo" e suas raízes são utilizadas para o tratamento de infecções uterinas, intestinais, gastrite, úlceras e artrite. Atualmente, o extrativismo e a destruição dos habitats naturais colocaram o algodão-do-campo na lista de espécies medicinais nativas prioritárias para conservação ex situ. O objetivo deste trabalho foi desenvolver uma metodologia para a conservação in vitro do algodão-do-campo e fornecer subsídios para estudos de micropropagação da espécie. Sementes de algodão-do-campo foram testadas quanto à germinação in vitro pela escarificação ou não das sementes em ácido sulfúrico e inoculação em meio de cultura MS. Para a conservação in vitro, segmentos nodais retirados das plântulas germinadas in vitro foram avaliados por 90 dias sob três regimes de temperatura (10, 20, e 25ºC) e em três concentrações de meio WPM (½, ¾ e pleno). Verificou-se que sementes escarificadas apresentaram percentual de germinação in vitro de 93,3 por cento aos 30 dias, valor significativamente superior aos 13,3 por cento observados nas sementes não escarificadas. A conservação da espécie in vitro mostrou-se viável, desde que as culturas sejam mantidas em câmara de crescimento a 20ºC em meio de cultivo ½WPM. Sob estas condições os explantes mantiveram um crescimento mínimo e percentual de sobrevivência de 100 por cento, após três meses de avaliação.
Cochlospermum regium is a plant from cerrado, caatinga and pantanal areas. In popular medicine, it is known as "algodão-do-campo" and its roots are used to treat uterine and intestinal infections, gastritis, ulcers and arthritis. Nowadays, extraction activities and the destruction of natural habitats has made "algodão-do-campo" one of the major native medicinal species for ex situ conservation. The aim of this work was to develop a methodology for the in vitro conservation of "algodão-do-campo", contributing to studies on the micropropagation of this species. In vitro germination was evaluated in "algodão-do-campo" seeds subjected to scarification or not with sulfuric acid and inoculation in MS medium. For in vitro conservation, nodal segments from in vitro-germinated seedlings were evaluated for 90 days at three temperatures (10, 20 and 25ºC) and three WPM medium concentrations (½, ¾ and full-strength). Scarified seeds presented 93.3 percent in vitro germination at 30 days of cultivation, a significantly higher value than the 13.3 percent observed for non-scarified seeds. The in vitro conservation of "algodão-do-campo" showed to be viable once cultures are kept in a growth chamber at 20ºC in ½ WPM medium. Under such conditions, the explants presented a minimal growth and 100 percent survival after three evaluation months.