scholarly journals The production and storage of a fermentor-grown bacterial culture containing Synergistes jonesii, for protecting cattle against mimosine and 3-hydroxy-4(1H)-pyridone toxicity from feeding on Leucaena leucocephala

2002 ◽  
Vol 53 (1) ◽  
pp. 1 ◽  
Author(s):  
A. V. Klieve ◽  
D. Ouwerkerk ◽  
A. Turner ◽  
R. Roberton

The leguminous shrub Leucaena leucocephala (leucaena) iswidely used as a forage species for cattle in tropical agriculture. However,leucaena contains the toxic amino acid mimosine. Both mimosine and its primaryruminal degradation product 3-hydroxy-4(1H)-pyridone (DHP) are toxic and theiraccumulation in the animal’s system results in hair loss, reducedliveweight gain, and goitre. The ruminal bacteriumngle cultivar bywithholding water. In Expt 2, plants of EP and MK were grown together in thesame container and received water daily with gradation in intensity of waterdeficit achieved by varying the daily water ration per container.All cultivars in each experiment exhibited commonly reported responses towater deficit, characterised by diminished evaporative surface area andincreased root : shoot ratio. The response of MK was primarily morphologicaland MK plants had smaller plant size, higher root : shoot ratio,

2002 ◽  
Vol 53 (1) ◽  
pp. 51 ◽  
Author(s):  
Phillip A. Crockett ◽  
Mohan B. Singh ◽  
C. K. Lee ◽  
Prem L Bhalla

Determination of genetic purity of F1-hybrid seeds is aquality control requirement in the production of hybrid Brassica vegetableseeds. Hybrid varieties of these vegetable crops have arisen from a limitedgermplasm base, making discrimination of parental and hybrid lines verylaborious and troublesome. The use of RAPD PCR for evaluating seed purity in acommercial F1-hybrid broccoli a single cultivar bywithholding water. In Expt 2, plants of EP and MK were grown together in thesame container and received water daily with gradation in intensity of waterdeficit achieved by varying the daily water ration per container.All cultivars in each experiment exhibited commonly reported responses towater deficit, characterised by diminished evaporative surface area andincreased root : shoot ratio. The response of MK was primarily morphologicaland MK plants had smaller plant size, higher root : shoot ratio, and a lowergrowth rate compared with temperate cultivars. By contrast, response oftemperate cultivars was primarily physiological; stomatal conductance oftemperate cultivars was lower and these cultivars had a greater tendency forleaf lamina osmotic a


2002 ◽  
Vol 53 (1) ◽  
pp. 29 ◽  
Author(s):  
S. G. Assuero ◽  
C. Matthew ◽  
P. Kemp ◽  
D. J. Barker ◽  
the late A. Mazzanti

Two glasshouse experiments were carried out to evaluate the morphological and physiological responses to water deficit of Mediterranean and temperate tall fescue (Festuca arundinacea Schreb.) cultivars. In Expt 1, 3 cultivars were studied: 2 temperate cultivars, Grasslands Advance (GA) and El Palenque (EP); and a Mediterranean cultivar, Maris Kasba (MK). Water deficit was induced in containers of 4 plants of a single cultivar by withholding water. In Expt 2, plants of EP and MK were grown together in the same container and received water daily with gradation in intensity of water deficit achieved by varying the daily water ration per container. All cultivars in each experiment exhibited commonly reported responses to water deficit, characterised by diminished evaporative surface area and increased root : shoot ratio. The response of MK was primarily morphological and MK plants had smaller plant size, higher root : shoot ratio, and a lower growth rate compared with temperate cultivars. By contrast, response of temperate cultivars was primarily physiological; stomatal conductance of temperate cultivars was lower and these cultivars had a greater tendency for leaf lamina osmotic adjustment than MK under the most stressful water deficit conditions studied. The morphological adaptations of MK were very effective in delaying the onset of water deficit in Expt 1 when plants were grown with others of the same cultivar, but rendered MK plants uncompetitive and more susceptible to water deficit in Expt 2 where plants of MK where interspersed with plants of a temperate cultivar.


2013 ◽  
Vol 39 (12) ◽  
pp. 2228 ◽  
Author(s):  
Ye FENG ◽  
Feng GUO ◽  
Bao-Long LI ◽  
Jing-Jing MENG ◽  
Xin-Guo LI ◽  
...  

1965 ◽  
Vol 7 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Miroslav Penka
Keyword(s):  

2021 ◽  
Author(s):  
Xuhui Zhou ◽  
Lingyan Zhou ◽  
Yanghui He ◽  
Yuling Fu ◽  
Zhenggang Du ◽  
...  

Abstract Biomass allocation in plants is fundamental for understanding and predicting terrestrial carbon storage. Recent studies suggest that climate warming can differentially affect root and shoot biomass, and subsequently alter root: shoot ratio. However, warming effects on root: shoot ratio and their underlying drivers at a global scale remain unclear. Using a global synthesis of >300 studies, we here show that warming significantly increases biomass allocation to roots (by 13.1%), and two factors drive this response: mean annual precipitation of the site, and the type of mycorrhizal fungi associated with a plant. Warming-induced allocation to roots is greater in relatively drier habitats compared to shoots (by 15.1%), but lower in wetter sites (by 4.9%), especially for plants associated with arbuscular mycorrhizal fungi compared to ectomycorrhizal fungi. Root-biomass responses to warming predominantly determine the biomass allocation in terrestrial plants suggesting that warming can reinforce the importance of belowground resource uptake. Our study highlights that the wetness or dryness of a site and plants’ mycorrhizal associations strongly regulate terrestrial carbon cycle by altering biomass allocation strategies in a warmer world.


2011 ◽  
Vol 35 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Fernanda Carlota Nery ◽  
Hilton Morbeck de Oliveira ◽  
Amauri Alves de Alvarenga ◽  
Sara Dousseau ◽  
Evaristo Mauro de Castro ◽  
...  

Ecophysiological studies under semi-controlled conditions in nurseries and greenhouses are essential to enable the use of native species to recover degraded areas and for commercial planting. Talisia subalbens (Mart) Radlk, 'cascudo', is a native fruiting species of the Cerrado on the verge of extinction. The ecophysiological performance of this species was evaluated in nursery conditions under different levels of shading (full sunshine, 30%, 50% and 70%). Initial growth, biomass allocation, gas exchange and chlorophyll content of the plants were analyzed. Full sunshine cultivated plants showed a higher accumulation of total, shoot, and root dry biomass. There was no significant difference in the root/shoot ratio among the treatments. Seedlings cultivated under full sunshine and 30% shading showed higher values for height, basal diameter, and leaf area. Differences in stomata conductance and photosynthesis rate were not observed among the different shading levels. Plants cultivated under 70% of shading had higher contents of chlorophyll a, b, and total. During the initial phase with higher levels of radiation were fundamental for the development of T. subalbens seedlings.


2015 ◽  
Vol 33 (1) ◽  
pp. 01-12 ◽  
Author(s):  
F.F. CORRÊA ◽  
R.H. MADAIL ◽  
S. BARBOSA ◽  
M.P. PEREIRA ◽  
E.M. CASTRO ◽  
...  

The objective of this work was to evaluate the effects of the population density of Typha angustifolia plants in the anatomical and physiological characteristics. Plants were collected from populations of high density (over 50% of colonization capacity) and low density (less than 50% of colonization capacity) and cultivated under controlled greenhouse conditions. Plants from both populations were grown in plastic trays containing 4 L of nutritive solution for 60 days. At the end of this period, the relative growth rate, leaf area ratio, net assimilatory rate, root/shoot ratio, leaf anatomy, root anatomy, and catalase and ascorbate peroxidase activities were evaluated. Plants from high density populations showed increased growth rate and root/shoot ratio. Low density populations showed higher values of stomatal index and density in leaves, as well as increased palisade parenchyma thickness. Root epidermis and exodermis thickness as well as the aerenchyma proportion of high density populations were reduced, these plants also showed increased vascular cylinder proportion. Only catalase activity was modified between the high and low density populations, showing increased values in low density populations. Therefore, different Typha angustifolia plants show differences in its anatomy and physiology related to its origins on high and low density conditions. High density population plants shows increased growth capacity related to lower apoplastic barriers in root and this may be related to increased nutrient uptake capacity.


2013 ◽  
Vol 31 (4) ◽  
pp. 259-266 ◽  
Author(s):  
Arjina Shrestha ◽  
Janet C. Cole

Water use, growth, and leaf necrosis of Burkwood viburnum, Korean spice viburnum, and leatherleaf viburnum were evaluated on plants grown in 0 (full sun), 30, or 60% shade during 2010 and 2011. In both years, total water use of Burkwood viburnum decreased with increased shade intensity. Water use of leatherleaf viburnum was lowest in 0% and highest in 30% shade. Daily water use was lower in 0% than in 30 or 60% shade for leatherleaf viburnum plants in August of both years and September of 2010 due to greater leaf necrosis, leaf abscission, and less growth in height and width. In both years, growth in height and width, and leaf number at harvest generally increased in all three species with increased shade intensity. All species had a larger leaf area, stem dry weight, and root dry weight in 30 and 60% than in 0% shade. Shade intensity did not influence root to shoot (R/S) ratio in Burkwood viburnum in 2010, but in 2011, a curvilinear relationship occurred between R/S ratio and shade intensity. Root to shoot ratio of Korean spice and leatherleaf viburnum decreased linearly in 2010 but curvilinearly in 2011 with increasing shade. Leaf necrosis ratings were lower in shaded plants of all three species in both years. Results indicate that greater plant growth, quality, and water use efficiency occurs when these three viburnum species are grown in shade than when they are grown in full sun.


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