Genetic differentiation of the dominant perennial grass Cenchrus ciliaris L. contributes to response to water deficit in arid lands

2012 ◽  
Vol 34 (1) ◽  
pp. 55 ◽  
Author(s):  
Amina Kharrat-Souissi ◽  
Alex Baumel ◽  
Franck Torre ◽  
Mohamed Chaieb
Keyword(s):  
Water Deficit ◽  
Aboveground Biomass ◽  
Vegetation Cover ◽  
Stomatal Density ◽  
Perennial Grass ◽  
Arid Lands ◽  
Arid Ecosystems ◽  
Cenchrus Ciliaris ◽  
Response To Water ◽  
The Impact

Perennial herbaceous plants are a key element of the vegetation cover in arid lands, during a long period of the year, but their persistence depends on their ability to cope with acute drought. This characteristic could become very important with the predicted climatic changes in arid lands because the persistence of perennial plants will be a key element countering the process of desertification. The aim of the present study was to compare experimentally the response to water deficit of different genotypes of the perennial grass Cenchrus ciliaris L. (buffelgrass). We analysed the impact of water deficit on productivity, time span of the vegetative growth and leaf traits. Overall, there was highly heritable variation in the responses to applied water deficit for the measured attributes, and five different groups of genotypes responded differently to water deficit. These groups of genotypes differently invested their energy to alter their phenotype in response to water deficit. Consequently, some genotypes were more strongly affected by the water deficit and their aboveground biomass showed the largest decrease. The group of genotypes which showed the smallest decrease of their aboveground biomass was characterised by less increase of leaf hairiness, a strong decrease of leaf area and also the strongest decrease of stomatal density on the abaxial epidermis. The current study provides evidence that the capacity of C. ciliaris to regulate its growth as an adaptive mechanism under water deficit is dependent on strong genetic variation that could affect its productivity and in consequence the vegetation cover of arid ecosystems.

scholarly journals Leaf application of silicon in young cacao plants subjected to water deficit

2016 ◽  
Vol 51 (3) ◽  
pp. 215-223 ◽  
Author(s):  
Leonardo Valandro Zanetti ◽  
Camilla Rozindo Dias Milanez ◽  
Vinícius Novo Gama ◽  
Marco Antonio Galeas Aguilar ◽  
Carlos Alberto Spaggiari Souza ◽  
...  
Keyword(s):  
Water Deficit ◽  
Theobroma Cacao ◽  
Stomatal Density ◽  
Block Design ◽  
Photochemical Efficiency ◽  
Randomized Complete Block Design ◽  
Use Efficiency ◽  
Sio2 Powder ◽  
The Stability ◽  
Response To Water

Abstract: The objective of this work was to evaluate the physiological and anatomical traits of plants of a cacao (Theobroma cacao) clone in response to water deficit after leaf application of silicon. A randomized complete block design was used, with four replicates, in a 2x3 factorial arrangement of two water regimes (irrigated or nonirrigated) and three silicon concentrations (0.0, 1.5, and 3.0 mg mL-1) applied in wettable SiO2 powder. The plants were evaluated 20 days after the irrigation regimes were applied. The use of SiO2 increased the stability of cell membranes and the photochemical efficiency of the plants under water deficit. The 1.5 mg mL-1 concentration of SiO2 increased photosynthetic rate, water use efficiency, and carboxylation efficiency, besides mitigating the effect of oxidative stress. Stomatal density was reduced in nonirrigated plants under the highest concentration of Si. The 1.5 mg mL-1 concentration of Si is considered optimal for the photosynthetic metabolism of young cacao plants under soil water limitation.

scholarly journals Plant Morphoecological Traits, Grass-Weed Interactions and Water Use Efficiencies of Grasses Used for Restoration of African Rangelands

2021 ◽  
Vol 8 ◽  
Author(s):  
Kevin Z. Mganga ◽  
Eric Kaindi ◽  
Aphaxard J. N. Ndathi ◽  
Luwieke Bosma ◽  
Theophilus Kioko ◽  
...  
Keyword(s):  
Water Use ◽  
Aboveground Biomass ◽  
Vegetation Cover ◽  
Perennial Grasses ◽  
Grass Species ◽  
Production Plant ◽  
Cenchrus Ciliaris ◽  
Basal Cover ◽  
Plant Densities ◽  
Water Use Efficiencies

Degradation characterized by depleted vegetation cover is a serious environmental problem in African rangelands. It poses a serious threat to millions of pastoralists and agropastoralists who depend on livestock as a source of livelihood. Consequently, there has been a growing global interest to consolidate efforts to restore degraded ecosystems. For example, the UN decade of Ecosystem Restoration initiative aims at uniting the world behind a common goal of preventing, halting and reversing the degradation of ecosystems. Grass reseeding using native perennial species has been identified as one of the practical ecological strategies for restoring degraded African rangelands, enhancing vegetation cover and forage production. Knowledge of the multifaceted performance of African rangeland grasses in terms of morphoecological traits, interaction with weeds and water use efficiencies is however largely limited and often elusive. Perennial grasses indigenous to African rangelands Cenchrus ciliaris L. (African foxtail grass), Enteropogon macrostachyus (Hochst. Ex A. Rich.) Monro ex Benth. (Bush rye grass) and Eragrostis superba Peyr. (Maasai love grass), were established in an African semi-arid rangeland under natural conditions to fill this knowledge gap. Morphoecological plant traits: aboveground biomass (shoot, leaf and stem) production, plant densities, basal cover, tiller densities and plant height were measured 9 months after establishment. Interaction between the target grass species and weeds and water use efficiencies (WUE) were also determined. Enteropogon macrostachyus displayed significantly higher values for plant densities, tiller densities and basal cover, indices commonly used to estimate the potential of grasses for ecological restoration. Eragrostis superba produced the highest shoot biomass and water use efficiencies. This is attributed to its higher leafy biomass fraction. Higher aboveground biomass production of E. superba demonstrate its suitability for enhancing rangeland productivity. Cenchrus ciliaris suppressed the weeds. This is linked to its aggressive and allelopathic nature. In conclusion, the three perennial grasses displayed distinct morphoecological traits. In order to achieve successful seed-based restoration of degraded African rangelands using native perennial grasses, careful selection species to maximize on their unique traits is recommended. Ultimately, this selection process should match the desired restoration outcomes and subsequent use of the rangeland.

scholarly journals The polyploid nature of Cenchrus ciliaris L. (Poaceae) has been overlooked: new insights for the conservation and invasion biology of this species – a review

2014 ◽  
Vol 36 (1) ◽  
pp. 11 ◽  
Author(s):  
Amina Kharrat-Souissi ◽  
Sonja Siljak-Yakovlev ◽  
Spencer C. Brown ◽  
Alex Baumel ◽  
Franck Torre ◽  
...  
Keyword(s):  
Perennial Grass ◽  
Invasion Biology ◽  
Molecular Data ◽  
Grazing Pressure ◽  
Arid Ecosystems ◽  
Evolutionary Development ◽  
Cenchrus Ciliaris ◽  
Ploidy Levels ◽  
Western Asia ◽  
Genetic Mechanisms

Climate change, associated with increased aridity, and high grazing pressure by livestock results in the scarcity and loss of perennial Poaceae in arid ecosystems. The species threatened by this include Cenchrus ciliaris L., a native perennial grass of the tropical and sub-tropical arid rangelands of Africa and Western Asia and now introduced in Central and South America, and Australia. This species reproduces predominantly through aposporous apomixis although sexual individuals have been occasionally identified. Cenchrus ciliaris is characterised by a significant, heritable, phenotypic polymorphism and three ploidy levels including tetraploids (2n = 4x = 36), pentaploids (2n = 5x = 45) and hexaploids (2n = 6x = 54). Under water-deficit conditions, C. ciliaris shows plasticity in growth characteristics and aboveground biomass. This phenotypic plasticity has led to the identification of genotypic-associated responses conferring more productivity. This underlines the importance of conserving the genetic diversity of C. ciliaris in order to ensure the persistence of the vegetation cover in the arid ecosystems in which it occurs. Observations from cytogenetic and molecular data converge to underline the possibility of sexual reproduction, recombination and gene flow within and between populations of C. ciliaris. Genetic mechanisms, such as polyploidy, hybridisation between ploidy levels and apomixes, are generating and then maintaining the diversity of C. ciliaris. This review emphasises the role of polyploidy in the evolutionary development of C. ciliaris and how it may be a crucial factor for its conservation in some countries and its weedy nature in others.

The yield of perennial grass stands on drained organic soils of Steppe

2016 ◽  
Vol 1 (90) ◽  
pp. 92-97
Author(s):  
I.T. Slusar ◽  
V.A. Serbenyuk ◽  
A.N. Gera ◽  
A.P. Solyanik ◽  
A.A. Tarasenko
Keyword(s):  
Zinc Sulphate ◽  
Foliar Application ◽  
Perennial Grass ◽  
Mineral Fertilizer ◽  
Dry Weight ◽  
Research Area ◽  
Organic Soils ◽  
Growth Promoters ◽  
Cobalt Sulfate ◽  
The Impact

Research on the impact of the introduction of micro fertilizers and growth promoters on a background of mineral fertilizer and without N90R45К120 spent on old peat in shallow carbonate floodplain r.Supiy, Yahotyn Kyiv region. Power peat horizon about 60-70 cm, 7,4-7,6 pH of the aqueous extract, stupas schedule 56-60%, density 0,49-0,52 assembly soil, total nitrogen content (%) - 1.9; gross forms of phosphorus - 0,4, potassium 0.2, 20% lime. In experiments studying biological rehoplant, radustym, Biolan, emistim, Jets, humisol, plantafol, radyfarm and micronutrients: copper, boric acid, manganese sulphate, zinc sulphate, potassium humates. Treatment drugs conducted in the spring by spraying mixtures. Space research area of 60 m2, three-time repetition. It is established that the use of growth stimulants and micronutrients in the background N90R45К120 provided the highest yield mixtures of years, against making BIOLan - 9.9 t / ha Radyfarmu - 9.6 t / ha Radostymu 9.3 t / ha dry weight. In areas for making other preparations were intermediate yield growth rates - 0.5 - 2.0 t / ha dry weight. Also good gains herbage yields obtained by making all kinds of micronutrients and growth stimulants in the background without making makrodobryv which was within 5.3 - 6.9 t / ha to control without fertilization - 4.5 t / ha dry weight. In deep peat copper fertilizer (25 kg / ha of copper sulphate or 5 kg / ha pirytnoho cinders) in all zones should be making every 3-4 years, and zinc, cobalt and molybdenum advisable to make time for the growing season, spring, by foliar application in such numbers: ammonium molibdenovokyslyy - 0.3 kg / ha; cobalt sulfate - 3 kg / ha zinc sulphate 0.5 kg / ha or placers these salts should be mixed with major fertilizer.

Kalahari Cheetahs

2017 ◽  
Author(s):  
Gus Mills ◽  
Margaret Mills
Keyword(s):  
Reproductive Success ◽  
Spatial Ecology ◽  
Prey Selection ◽  
Arid Ecosystems ◽  
Foraging Success ◽  
Ecological Processes ◽  
Demographic Groups ◽  
Important Prey ◽  
Hunting Behaviour ◽  
The Impact

This book demonstrates how cheetahs are adapted to arid savannahs like the southern Kalahari, and makes comparisons with other areas, especially the Serengeti. Topics dealt with are: demography and genetic status; feeding ecology, i.e. methods used for studying diet, diets of different demographic groups, individual diet specializations of females, prey selection, the impact of cheetah predation on prey populations, activity regimes and distances travelled per day, hunting behaviour, foraging success and energetics; interspecific competition; spatial ecology; reproductive success and the mating system; and conservation. The major findings show that cheetahs are well adapted to arid ecosystems and are water independent. Cheetah density in the study area was stable at 0.7/100 km2 and the population was genetically diverse. Important prey were steenbok and springbok for females with cubs, gemsbok, and adult ostrich for coalition males, and steenbok, springhares, and hares for single animals. Cheetahs had a density-dependent regulatory effect on steenbok and springbok populations. Females with large cubs had the highest overall food intake. Cheetahs, especially males, were often active at night, and competition with other large carnivores, both by exploitation and interference, was slight. Although predation on small cubs was severe, cub survival to adolescence was six times higher than in the Serengeti. There was no difference in reproductive success between single and coalition males. The conservation priority for cheetahs should be to maintain protected areas over a spectrum of landscapes to allow ecological processes, of which the cheetah is an integral part, to proceed unhindered.

scholarly journals Urban Fire Severity and Vegetation Dynamics in Southern California

2020 ◽  
Vol 13 (1) ◽  
pp. 19
Author(s):  
Lauren E. H. Mathews ◽  
Alicia M. Kinoshita
Keyword(s):  
Vegetation Cover ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Current Knowledge ◽  
Fire Severity ◽  
Satellite Image ◽  
Burn Severity ◽  
Native Vegetation ◽  
Riparian Areas ◽  
The Impact

A combination of satellite image indices and in-field observations was used to investigate the impact of fuel conditions, fire behavior, and vegetation regrowth patterns, altered by invasive riparian vegetation. Satellite image metrics, differenced normalized burn severity (dNBR) and differenced normalized difference vegetation index (dNDVI), were approximated for non-native, riparian, or upland vegetation for traditional timeframes (0-, 1-, and 3-years) after eleven urban fires across a spectrum of invasive vegetation cover. Larger burn severity and loss of green canopy (NDVI) was detected for riparian areas compared to the uplands. The presence of invasive vegetation affected the distribution of burn severity and canopy loss detected within each fire. Fires with native vegetation cover had a higher severity and resulted in larger immediate loss of canopy than fires with substantial amounts of non-native vegetation. The lower burn severity observed 1–3 years after the fires with non-native vegetation suggests a rapid regrowth of non-native grasses, resulting in a smaller measured canopy loss relative to native vegetation immediately after fire. This observed fire pattern favors the life cycle and perpetuation of many opportunistic grasses within urban riparian areas. This research builds upon our current knowledge of wildfire recovery processes and highlights the unique challenges of remotely assessing vegetation biophysical status within urban Mediterranean riverine systems.

scholarly journals Candidate genes and SNPs associated with stomatal conductance under drought stress in Vitis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Massimiliano Trenti ◽  
Silvia Lorenzi ◽  
Pier Luigi Bianchedi ◽  
Daniele Grossi ◽  
Osvaldo Failla ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Candidate Genes ◽  
Water Deficit ◽  
Genetic Basis ◽  
Phenotypic Diversity ◽  
Snp Array ◽  
A Genome ◽  
Raffinose Synthase ◽  
Response To Water

Abstract Background Understanding the complexity of the vine plant’s response to water deficit represents a major challenge for sustainable winegrowing. Regulation of water use requires a coordinated action between scions and rootstocks on which cultivars are generally grafted to cope with phylloxera infestations. In this regard, a genome-wide association study (GWAS) approach was applied on an ‘ad hoc’ association mapping panel including different Vitis species, in order to dissect the genetic basis of transpiration-related traits and to identify genomic regions of grape rootstocks associated with drought tolerance mechanisms. The panel was genotyped with the GrapeReSeq Illumina 20 K SNP array and SSR markers, and infrared thermography was applied to estimate stomatal conductance values during progressive water deficit. Results In the association panel the level of genetic diversity was substantially lower for SNPs loci (0.32) than for SSR (0.87). GWAS detected 24 significant marker-trait associations along the various stages of drought-stress experiment and 13 candidate genes with a feasible role in drought response were identified. Gene expression analysis proved that three of these genes (VIT_13s0019g03040, VIT_17s0000g08960, VIT_18s0001g15390) were actually induced by drought stress. Genetic variation of VIT_17s0000g08960 coding for a raffinose synthase was further investigated by resequencing the gene of 85 individuals since a SNP located in the region (chr17_10,497,222_C_T) was significantly associated with stomatal conductance. Conclusions Our results represent a step forward towards the dissection of genetic basis that modulate the response to water deprivation in grape rootstocks. The knowledge derived from this study may be useful to exploit genotypic and phenotypic diversity in practical applications and to assist further investigations.

miR398 and miR408 are up-regulated in response to water deficit in Medicago truncatula

Planta ◽  
2009 ◽  
Vol 231 (3) ◽  
pp. 705-716 ◽  
Author(s):  
Inês Trindade ◽  
Cláudio Capitão ◽  
Tamas Dalmay ◽  
Manuel Pedro Fevereiro ◽  
Dulce Metelo dos Santos
Keyword(s):  
Water Deficit ◽  
Medicago Truncatula ◽  
Response To Water
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