Respuestas morfológicas y anatómicas de Tessaria absinthioides (Hook. et Arn.) DC. a la salinidad

Abstract

Respuestas morfológicas y anatómicas deABSTRACT -(Morphology and anatomy of Tessaria absinthioides (Hook. et Arn.) DC. under salinity conditions).T. absinthioides, Inuleae, Compositae, is a weedy species that is spreading in the irrigation area of the Colorado River, Argentina. This species can be found in normal and saline soils. Morphological and anatomical variables were measured with two salts, sodium chloride and sodium sulfate, with three levels of osmotic potential -0.4, -0.8 and -1.5 MPa, in hydroponic culture, using Hoagland solution as the cultivation media. The total diameter of the roots of plants growing in Na 2 SO 4 and NaCl increased when the osmotic potential was -0.4 MPa. In plants growing in NaCl this may have resulted from the increase in the size of the cortical cells and in plants growing in Na 2 SO 4 , the diameter increased may be due to an increase in the cambial activity. The number and length of shoot internodes decreased with increasing salinity, even though this was not statistically significant. In comparison to the control, the total diameter of the shoot increased at -0.4 MPa and decreased with the reduction of the osmotic potential. In comparison to the control, the length of the leaves decreased at -0.4 MPa and the leaves width increased at the same concentration. The palisade parenchyma appeared less developed in saline conditions. In comparison to the control, the number of hairs increased at -0.4 MPa. T. absinthioides acts as a semihalophytic species, according to the salt ranks it tolerates. The mechanisms of adaptation to saline conditions are succulence in root and stunted growth if the salt in the media is NaCl, and the production of haloxeromorphic characters if the salt in the media is Na 2 SO 4 RESUMO -(Respostas morfológicas e anatômicas de Tessaria absinthioides (Hook. et Arn.) DC. à salinidade).T.absinthioides,Inulae, Compositae, é uma espécie que se encontra difundida como erva daninha na área de irrigação do Rio Colorado, Argentina, tanto em solos salinos como normais. A fim de determinar a capacidade de adaptação da espécie a diferentes condições de salinidade, foram montados experimentos onde a planta foi submetida a dois tipos de sais, cloreto de sódio e sulfato de sódio, com três níveis de potencial osmótico: -0,4, -0,8 e -1,5 MPa, em cultura hidropônica, utilizando a solução de Hoagland como meio de cultura. O experimento foi avaliado com base nas variações quantitativas dos caracteres morfológicos e anatômicos. Os resultados mostram que o diâmetro das raízes aumenta quando o potencial osmótico dos sais é -0,4 MPa; isto é devido ao aumento de tamanho das células da casca nas plantas submetidas ao NaCl ou ao aumento da atividade cambial nas colocadas em Na 2 SO 4 . No caule diminui o número e o comprimento dos entrenós, mas as diferenças observadas não são estatisticamente significativas. Tanto o diâmetro do caule, como o da raiz, aumentam quando o potencial osmótico atinge -0,4MPa, e diminuem com a redução do mesmo. Quando o potencial osmótico é -0,4 MPa, a fo...

Uso de humatos de vermicompost para disminuir el efecto de la salinidad en el crecimiento y desarrollo de albahaca (Ocimum basilicum L.)

“…La respuesta de la biomasa fresca y seca de tallo y hoja al humatos de vermicompost, mostró valores mayores con la aplicación del humato, lo que sugiere que este tiende a mitigar el efecto negativo del estrés salino, que se manifiesta en la producción de biomasa. Degano (1999) probó dos fuentes de sal (NaCl y NaSO 4 ) en el crecimiento y peso fresco de tallo de Tessaria absinthoides, encontrando que a medida que se incrementó la concentración salina, independientemente de la fuente, la biomasa fresca disminuyó, atribuyendo esta disminución a que la distancia y longitud de los entrenudos tuvieron esta misma respuesta, proporcionándole a la planta una apariencia achaparrada.…”

“…The response of fresh and dry biomass of stem and leaf to humates vermicompost showed higher values with the application of humate, suggesting that this tends to mitigate the negative effect of saline stress, which manifest in biomass production. Degano (1999) tested two sources of salt (NaCl and NaSO 4 ) on growth and fresh stem weight of Tessaria absinthoides, finding that as salt concentration increased, regardless of source, fresh biomass decreased, ascribing this decrease to the distance and length of internodes had this same response, giving the plant a short appearance.…”

Oxygation Enhances Growth, Gas Exchange and Salt Tolerance of Vegetable Soybean and Cotton in a Saline Vertisol

“…It invariably decreased with increasing salinity and increased with oxygation (Tables 1 and 6). Stem diameter of Tessaria absinthioides grown hydroponically with additional Na 2 SO 4 and NaCl declined when the osmotic potential was −0.8 or −1.5 MPa compared with −0.4 MPa (Degano 1999), while Kafkafi and Brenstein (1996) reported an increased root diameter of Latuca sativa with aeration using soil aerators. Of note, stem diameter was positively correlated with biomass yield for vegetable soybean ( r 2 = 0.949***, n = 24), and with lint yield in cotton ( r 2 = 0.850***, n = 24).…”

Anatomia e ultra-estrutura foliar de Cyperus maritimus Poir. (Cyperaceae): estratégias adaptativas ao ambiente de dunas litorâneas

“…O parênquima aqüífero é também considerado um caráter importante para plantas submetidas a condição salina (Fahn & Cutler 1992;Degano 1999). Já que as folhas de halófitas tendem a acumular NaCl por ajuste osmótico, aumentando a suculência do órgão (Flowers & Yeo 1986).…”