scholarly journals Adubação nitrogenada e potássica de bromeliáceas cultivadas em fibra de coco e esterco bovino

2009 ◽  
Vol 27 (3) ◽  
pp. 286-289 ◽  
Author(s):  
Tatiana L do Amaral ◽  
Janie M Jasmim ◽  
Pedro Ivo Nahoum ◽  
Claudimar B de Freitas ◽  
Cintia S Sales

Neste trabalho objetivou-se avaliar o efeito de doses de nitrogênio e de potássio no crescimento e teor foliar de nutrientes de quatro bromeliáceas comerciais e propor uma formulação de adubação adequada para cada planta estudada. O experimento foi em esquema fatorial (4 x 4), sendo quatro doses de nitrogênio (0; 375; 562,6 e 750 mg de N L-1) e quatro doses de potássio (0; 468,8; 703,2 e 937,6 mg de K L-1), em delineamento em blocos ao acaso, com quatro repetições para Aechmea blanchetiana e Neoregelia 'Sheba' e três repetições para Orthophytum gurkenii e Vriesea gigantea, duas plantas por parcela. As mudas de Aechmea blanchetiana e Neoregelia 'Sheba' foram cultivadas em substrato composto por 50% de fibra de coco + 50% de esterco bovino; as de Orthophytum gurkenii e Vriesea gigantea, em 100% de fibra de coco. As doses de nitrogênio 0; 375; 562,6 e 750 mg de N L-1 e potássio 0; 468,8; 703,2 e 937,6 mg de K L-1 no substrato correspondem, respectivamente, a 0; 187,5; 281,3 e 375 mg N/planta e 0; 234,4; 351,6 e 468,8 mg K/planta. A adubação fosfatada foi fixa, 50 mg de P L-1 no substrato, correspondendo a 25 mg P/planta, exceto para Neoregelia 'Sheba', que foi inoculada com 25 mL/vaso do inóculo micorrízico misto (Glomus geosporum, Acaulospora laevis, Acaulospora mellea) e não recebeu adubação fosfatada. A adubação com 305,1 mg N/planta foi a que proporcionou maior incremento na altura de Aechmea blanchetiana. Em Orthophytum gurkenii; a adubação com 250 mg N/planta proporcionou o maior número de folhas e o maior diâmetro da roseta. As adubações nitrogenada e potássica não beneficiaram o crescimento das plantas de Vriesea gigantea. Em Neoregelia 'Sheba', a dose de 315 mg N/planta causou maior incremento em altura e diâmetro da roseta.

2005 ◽  
Vol 71 (11) ◽  
pp. 6673-6679 ◽  
Author(s):  
David Roesti ◽  
Kurt Ineichen ◽  
Olivier Braissant ◽  
Dirk Redecker ◽  
Andres Wiemken ◽  
...  

ABSTRACT Spores of the arbuscular mycorrhizal fungi (AMF) Glomus geosporum and Glomus constrictum were harvested from single-spore-derived pot cultures with either Plantago lanceolata or Hieracium pilosella as host plants. PCR-denaturing gradient gel electrophoresis analysis revealed that the bacterial communities associated with the spores depended more on AMF than host plant identity. The composition of the bacterial populations linked to the spores could be predominantly influenced by a specific spore wall composition or AMF exudate rather than by specific root exudates. The majority of the bacterial sequences that were common to both G. geosporum and G. constrictum spores were affiliated with taxonomic groups known to degrade biopolymers (Cellvibrio, Chondromyces, Flexibacter, Lysobacter, and Pseudomonas). Scanning electron microscopy of G. geosporum spores revealed that these bacteria are possibly feeding on the outer hyaline spore layer. The process of maturation and eventual germination of AMF spores might then benefit from the activity of the surface microorganisms degrading the outer hyaline wall layer.


2012 ◽  
Vol 48 (No. 1) ◽  
pp. 31-36 ◽  
Author(s):  
K. Yadav ◽  
N. Singh ◽  
A. Aggarwal

Spilanthes acmella (Asteraceae) is an endangered ornamental cum medicinal annual herb. This study reports on the effect of two arbuscular mycorrhizal fungi (Glomus mosseae and Acaulospora laevis) applied either alone or in combination on post-transplanting performance of micropropagated S. acmella. Complete plantlets of S. acmella were raised by direct organogenesis from nodal explants on Murashige and Skoog medium supplemented with various cytokinins. S. acmella plantlets responded to all three mycorrhizal treatments in a significantly different way. G. mosseae enhanced the survival rate of S. acmella plantlets to 100%. Plant height, plant spread, number of branches per plant, number of leaves per plant, leaf area, biomass production, and chlorophyll content were significantly higher in AM inoculated plantlets as compared to the uninoculated ones. This clearly demonstrates that AM inoculation improved not only the survival rate of micropropagated plantlets but also their growth and biomass yield.  


2010 ◽  
Vol 45 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Rui S. Oliveira ◽  
Louisa Robinson Boyer ◽  
Maria F. Carvalho ◽  
Peter Jeffries ◽  
Miroslav Vosátka ◽  
...  

2007 ◽  
Vol 5 (24) ◽  
pp. 773-784 ◽  
Author(s):  
A Schnepf ◽  
T Roose ◽  
P Schweiger

In order to quantify the contribution of arbuscular mycorrhizal (AM) fungi to plant phosphorus nutrition, the development and extent of the external fungal mycelium and its nutrient uptake capacity are of particular importance. We develop and analyse a model of the growth of AM fungi associated with plant roots, suitable for describing mechanistically the effects of the fungi on solute uptake by plants. The model describes the development and distribution of the fungal mycelium in soil in terms of the creation and death of hyphae, tip–tip and tip–hypha anastomosis, and the nature of the root–fungus interface. It is calibrated and corroborated using published experimental data for hyphal length densities at different distances away from root surfaces. A good agreement between measured and simulated values was found for three fungal species with different morphologies: Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders; Glomus sp.; and Acaulospora laevis Gerdemann & Trappe associated with Trifolium subterraneum L. The model and findings are expected to contribute to the quantification of the role of AM fungi in plant mineral nutrition and the interpretation of different foraging strategies among fungal species.


1978 ◽  
Vol 56 (14) ◽  
pp. 1691-1695 ◽  
Author(s):  
Randolph J. Molina ◽  
James M. Trappe ◽  
Gerald S. Strickler

Vesicular–arbuscular mycorrhizal infection and associated mycorrhizal fungi were examined for Festuca viridula, Festuca idahoensis, Festuca scabrella, Festuca thurberi, Festuca ovina, and Festuca arizonica occurring in Festuca-dominated grasslands in the western United States and Canada. All plants were mycorrhizal. Nearly all had mycorrhizal infection in 75% or more of their fine root length. Although levels of infection were consistently high, spore numbers were generally low. No differences in the degree of infection between Festuca species or habitats were observed.Eleven mycorrhizal fungi were identified and ranked by decreasing frequency as follows: Glomus fasciculatus, Glomus tenuis, Gigaspora calospora, Acaulospora laevis, Glomus macrocarpus var. macrocarpus, Glomus microcarpus, Acaulospora scrobiculata, Glomus mosseae, Glomus macrocarpus var. geosporus, Sclerocystis rubiformis, and an unidentified Acaulospora species. It was common to find two or more species infecting an individual plant. The mean number of fungal associates per community site ranged from 2.7 species for F. idahoensis to 5.0 species for F. arizonica. We found no evidence for specificity of any of the mycorrhizal fungi for any particular Festuca host.


2014 ◽  
Vol 2 (01) ◽  
pp. 45-50 ◽  
Author(s):  
Gaurav Bhushan ◽  
Santosh Kr Sharma ◽  
Priyanka Sagar ◽  
Nishtha Seth ◽  
A. P. Singh

Myrica esculenta (Myricaceae) and Syzygium cumini(Myrtaceae), the Indian traditional fruits The effect of different level of salinity on growth, nodulation and Nitrogen fixation of single and dual inoculated tree legumes which help arbascular mycorrhizal fungi (AMF) Acaulospora laevis Gerd. and Trappe with Rhizobium bacteria in the presence of different levels of salinity (concentration of NaCl) conducted in earthen pots in a completely randomized block design with three replications resulted in effective plant growth, shoot and root biomasses, nodulation and N2 fixation. The effect of different levels of salinity (concentration of NaCl) on growth, nodulation and N2 fixation of single (Rhizobium or AMF alone) and dual inoculated (Rhizobium + AMF ) tree legume has a pot culture experiment using The parameter growth , nodulation, nitrogen fixation and % AMF colonization of roots were considerable influenced with the increase in salt concentration from 0.5 % to 4.0 % NaCl. It was observed that the mycorrhizal tree legume (inoculated with the most preferred AMF Acaulospora laevis) performed better in the increasing levels of salinity in comparison to non-mycorrhozal ones. These investigations suggested a protective role play by AMF in providing resistance to the tree legume against injurious effects of salinity. Inoculation of efficient strain of AMF (Acaulospora laevis) during the course of study, prevented the injurious effects of salinity in the test plants due to enhanced water and sustainable nutrient uptake thereby promoting growth, nodulation and biogeochemical N2 cycle (fixation of nitrogen) of the tree legume under investigation.


1984 ◽  
Vol 62 (11) ◽  
pp. 2272-2277 ◽  
Author(s):  
Laura A. Dickman ◽  
Anthony E. Liberta ◽  
Roger C. Anderson

The percentage of vesicular–arbuscular mycorrhizal (VAM) colonization of little bluestem (Schizachyrium scoparium) (Michx.) Nash.) and VAM spore populations in the rhizosphere of little bluestem from four prairie areas in Illinois were studied. At Goose Lake Prairie, a significant positive correlation (r = 0.77, p < 0.01) was found between soil moisture and density of VAM spores, but soil moisture and percent VAM colonization were not significantly correlated at any of its sites. Percentage of VAM colonization tended to be higher at study areas where little bluestem was a dominant species. However, spore numbers and abundance of little bluestem tended to be inversely related. Colonization decreased from May to July at all areas and this trend frequently continued into September. Month of sample collection had no significant effect on spore numbers except at Reavis Hill Prairie. The endophyte isolated at all areas was Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. & Trappe. Other species, such as Gigaspora heterogama (Nicol. & Gerd.) Gerd. & Trappe and Acaulospora laevis Gerd. & Trappe, were more restricted in their distribution.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Navnita Sharma ◽  
Kuldeep Yadav ◽  
Ashok Aggarwal

The present investigation aimed to quantify the difference in response of twoPhaseolus mungoL. cultivars (i.e., UH-1 and IPU-94-1) toGlomus mosseae(G), that is,Funneliformis mosseae,Acaulospora laevis(A), andTrichoderma viride(T), in different combinations or alone. All the treatments were inoculated withBradyrhizobium japonicumto ensure nodulation as soil used in the experiment was sterilized. After 120 days of inoculation, plants were analyzed for chlorophyll content, nodulation, mycorrhization, leaf area, and protein content. Results indicate variation in growth response of two cultivars with different treatments. Triple inoculation of plants with G + A + T proved to be the best treatment for growth followed by G + T in both cultivars. Our work allowed the selection ofP. mungoL. cultivar UH-1 as highly mycorrhizal responsive as compared to IPU-94-1 andG. mosseaeto be an efficient bioinoculant as compared toA. laevisfor growth enhancement ofP. mungo. Further characterization ofP. mungogenotypes will enhance our knowledge of physiological and genetic mechanism behind increase in plant growth and yield due to AM symbiosis.


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