Haloxylon Persicum Research Articles

Physio-ecological response of Haloxylon persicum photosynthetic shoots to drought stress

This paper studied the seasonal characteristics to resist the drought stress of Haloxylon persicum Bge. Ex Boiss. et Buhse photosynthetic shoots at habitat. The results showed that the predominant drought resistance factors were varied at the different stage from growth to development. In the blooming season (from May 31 to June 29), endogenous ABA contents were rare; stomatal conductance and photosynthesis intensity were the highest at the whole stage from growth to development; soluble sugars contents had a decreasing trend and proline contents increased a little that made proline become the predominant factor to resist the drought under this light water stress. In the hot summer (from June 29 to July 26), ABA contents accumulated rapidly; stomatal conductance dropped to the lowest level of the growth and development; chlorophyll was also decomposed; both soluble sugars and proline contents showed the trend of quickly accumulating, but the former was faster than the latter. It was due to stomatal limitation and osmotic organic molecules accumulation that would affect the photosynthetic shoots to resist severe drought stress. At the late period of the development (from Aug 9 to Aug 22), ABA rapidly accumulated, its contents got to the highest level of whole life-span; stomatal conductance increased a little; proline and soluble sugars contents changed little at high level; while the ratios of ABA to CTK content and ABA to IAA content got up obviously, the effect to resist drought stress on high content ABA was inhibited by endogenous plant hormone CTK and IAA, then the continuing accumulation of proline and soluble sugars would be prevented. Osmosis of organic molecules was the most important factor to adjust leaves to severe water stress at this period.

Nutritional and osmotic roles of nitrate in a euhalophyte and a xerophyte in saline conditions

The effects of salinity and nitrogen (N) on growth and the role of NO3- in osmotic adjustment in the leaf-succulent euhalophyte Suaeda physophora and the stem-succulent xerophyte Haloxylon persicum were evaluated. Seedlings were exposed to 1 or 300 mm NaCl in 0.05, 1 or 10 mm NO3- -N treatments for 24 d. At 10 mm NO3-, 300 mm NaCl had no adverse effect on the concentration of NO3-, the content of organic N, and the estimated contribution of NO3- to osmotic potential in leaves of S. physophora, but markedly reduced these in stems of H. persicum. At 300 mm NaCl, more NO3- but less Cl- and Na+ were involved in osmotic adjustment in leaves of S. physophora compared with that in stems of H. persicum. The contribution of NO3- to osmotic potential was much higher in S. physophora, but lower in H. persicum, than that of amino acids at 300 mm NaCl. The nutritional and osmotic roles of NO3- -N seem to be more important in the euhalophyte S. physophora than in the xerophyte H. persicum under saline conditions. These characteristics may determine the natural distributions of the two species in saline or arid environments.

Eco-Environmental Evolution, Control, and Adjustment for Aibi Lake Catchment

Aibi Lake in north Xinjiang is a typical lake of the arid area, but with a peculiar wetland-arid area ecosystem. Due to the climate becoming drier and the disturbance of human activities, the eco-environment of Aibi Lake catchment has degraded. It was found in our study that there were spatial-temporal changes of vegetation cover, plant species, and soil physical and chemical properties in the catchment. In the upper section of alluvial-fluvial plains, the desertified steppe of Stipa and Artemisia spp. is developed with vegetation cover of some 50%. Haloxylon ammodendron desert occupies the lower section with vegetation cover of some 60%. In these regions with an intensive human disturbance, vegetation has degraded into herb vegetation of annual plant complexes. On the margins of the alluvial-fluvial fans, the lakeshore, and the surrounding regions where the river mouths join the lake, different azonal vegetation-Phragmites communis marsh, Phragmites communis meadow, and Tamarix shrubs-have developed with a vegetation cover of some 80%. On heavier, salinized land, succulent halophyte desert vegetation dominated by Halocnemum strobilaceum has formed with a fractional canopy cover of 10-15%. Haloxylon persicum, Aristida pennata, and other species with a vegetation cover of 30-50% grow in the sand desert zone on the periphery in the lake. In contrast with the 1950s, the vegetation cover around the lakebed and at the river deltas has slightly increased; however, the vegetation cover around the periphery of the lake has decreased and the plant species have still degraded. The surface soils on the windward area and the dried lakebed that have lost vegetation protection have become coarser, whereas the land on the leeward side of the lake has accumulated fine particles. In contrast with the 1980s, soil organic matter has declined markedly. The analyses of climatic data show that the number of days of drifting dust in Jinghe County and Bole City increased in the last 20 years. In the investigation, we found that intensively developed land, the bare lakebed, and abandoned cultivated land provided a great deal of material for drifting dust. In conclusion, we consider the eco-environmental degradation resulting from the inappropriate human activities and put forward recommendations for land-use adjustment and dust control.

Osmotic adjustment traits of Suaeda physophora, Haloxylon ammodendron and Haloxylon persicum in field or controlled conditions

The osmotic adjustment traits of Suaeda physophora (euhalophyte), Haloxylon ammodendron (xero-halophyte) and Haloxylon persicum (xerophyte) were investigated both in field and under controlled conditions. The results showed that percentage of inorganic solutes in total solutes was over 90%, while the estimated contribution of Na + to Ψ s was over 50% for the two halophytic species, in field condition. The percentages of inorganic solutes and organic solutes were 66% and 34%, respectively, and the estimated contribution of Na + to Ψ s was less than 18%, while the estimated contribution of soluble sugars to Ψ s was over 20% in H. persicum, in field condition. The estimated contribution of proline to Ψ s was less than 0.2% for all species both in field and under salt stress in a greenhouse experiment. The estimated contribution of NO 3 − to Ψ s was less than 4% for all species in field condition. In greenhouse experiment, the concentration of NO 3 − was higher under various NaCl treatments than that in control condition for S. physophora; the estimated contribution of NO 3 − to Ψ s was over 7% in S. physophora, and it was higher than that in other species at various treatments. In conclusion, inorganic ions especially Na + were more important in osmoregulation for S. physophora and H. ammodendron to adapt to saline and arid environment, while organic solutes, especially soluble sugars played more important role in drought adaptation in the xerophyte, H. persicum. Proline did not play an important role in osmoregulation for all species both in field and controlled conditions. NO 3 − played more important role in osmoregulation in S. physophora and H. ammodendron cultured in full-strength Hoagland's nutrient solution under NaCl treatments compared with that growing in saline soils in field condition.

Strategies for Adaptation of Suaeda physophora, Haloxylon ammodendron and Haloxylon persicum to a Saline Environment During Seed-Germination Stage

Germination is very important for plant establishment in arid regions. The strategies taken by halophytes during the seed germination stage to adapt to saline environments in an arid zone were investigated in Suaeda physophora (euhalophyte), Haloxylon ammodendron (xero-halophyte) and Haloxylon persicum (xerophyte). Seeds of S. physophora, H. ammodendron and H. persicum were exposed to a range of iso-osmotic NaCl and PEG solutions. Seed germination in, and recovery germination from, high NaCl were recorded. The effects of iso-osmotic NaCl and PEG on seed water uptake and changes in ion content were measured. In addition, the structure of seeds and Na+ distribution in the seed coat and embryos of dry seeds were investigated. The relative increase in fresh weight of germinating seeds was markedly reduced in -2.24 MPa PEG compared with that in -2.24 MPa NaCl, while the opposite trend was found in concentration of K+ during the initial 9 h for all species. Haloxylon ammodendron and S. physophora had a higher recovery germination from -3.13 MPa NaCl compared with H. persicum. Seeds of all species had no endosperm. More Na+ was compartmentalized in the seed coats of the two halophytic species compared with that in the xerophyte H. persicum. The effect of NaCl on seed germination was due to both osmotic stress and ion toxicity for the three species. High soil salinity and a high content of Na+ in seeds may induce more seeds to remain ungerminated in S. physophora and H. ammodendron. Morphological structure and adaptation to salinity during seed germination may determine the geographical distribution of H. ammodendron and S. physophora in certain saline regions.

Modern pollen precipitation from an elevational transect in central Jordan and its relationship to vegetation

AimTo explore the relationship between modern pollen precipitation and vegetation patterns in an arid region of the Middle East.LocationData come from the central Jordan Rift from 1700 m elevation in the highlands to 300 m below sea level in the Dead Sea basin.MethodsModern pollen samples and descriptive vegetation data were collected from twenty‐one locations at 100 m elevational intervals from the highest elevations on the eastern side of the rift valley, where woodlands grow, to the lowest elevation desert on earth, characterized by drought and salt tolerant plants. Pollen percentage data from each vegetation zone are compared descriptively and numerically using cluster and Principal Components Analyses (PCA).ResultsThree major vegetation zones: woodland, shrub steppe, and desert scrub, are identified by their dominant plant species. The widely spaced tree, Quercus calliprinos Webb, defines the Quercus L. woodland that grows above 1500 m elevation. The shrub steppe can be divided into two subzones found between about 1500 and 900 m elevation: Artemisia herba‐alba Asso shrub steppe and Artemisia L. shrub steppe with Juniperus phoenica L. Desert scrub dominates the lower elevation landscape with Hammada salicornia (Moq.) Iljin the dominant shrub between 900 and 200 m and Haloxylon persicum Bge. found below 200 m elevation.Pollen spectra reflect the elevational vegetation zones. In particular, Quercus L., Juniperus L. and Tamarix L. pollen are abundant where the trees grow. Highly variable amounts of non‐arboreal pollen taxa – primarily Artemisia L. and Chenopodiaceae Vent. – differentiate shrub steppe from desert scrub vegetation. Cluster and PCA of pollen data support the qualitative vegetation zonation.Main conclusionsThe main vegetation zones along the Jordan Rift from 1700 to –300 m elevation can be distinguished by their modern pollen precipitation. Open vegetation types, in particular, can be recognized by their pollen spectra. High amounts of Artemisia L. pollen distinguish the moister upper elevations where Artemisia L. steppe grows. In contrast, greater amounts of Chenopodiaceae Vent. pollen characterize the drier, lower elevation deserts.

Anatomy, chloroplast structure and compartmentation of enzymes relative to photosynthetic mechanisms in leaves and cotyledons of species in the tribe Salsoleae (Chenopodiaceae)

Certain members of the family Chenopodiaceae are the dominant species of the deserts of Central Asia; many of them are succulent halophytes which exhibit C 4 -type CO 2 fixation of the NAD- or NADP-ME (malic enzyme) subgroup. In four C 4 species of the tribe Salsoleae, the Salsoloid-type Kranz anatomy in leaves or stems was studied in relation to the diversity in anatomy which was found in cotyledons. Halocharis gossypina, has C 4 NAD-ME Salsoloid-type photosynthesis in leaves and C 3 photosynthesis in dorsoventral non-Kranz cotyledons; Salsola laricina has C 4 NAD-ME Salsoloid-type leaves and C 4 NAD-ME Atriplicoid-type cotyledons; Haloxylon persicum, has C 4 NADP-ME Salsoloid-type green stems and C 3 isopalisade non-Kranz cotyledons; and S. richteri has C 4 NADP-ME Salsoloid-type leaves and cotyledons. Immunolocalization studies on Rubisco showed strong labelling in bundle sheath cells of leaves and cotyledons of organs having Kranz anatomy. The C 4 pathway enzyme phosphoenolpyruvate carboxylase was localized in mesophyll cells, while the malic enzymes were localized in bundle sheath cells of Kranz-type tissue. Immunolocalization by electron microscopy showed NAD-ME is in mitochondria while NADP-ME is in chloroplasts of bundle sheath cells in the respective C 4 types. In some C 4 organs, it was apparent that subepidermal cells and water storage cells also contain some chloroplasts which have Rubisco, store starch, and thus perform C 3 photosynthesis. In non-Kranz cotyledons of Halocharis gossypina and Haloxylon persicum, Rubisco was found in chloroplasts of both palisade and spongy mesophyll cells with the heaviest labelling in the layers of palisade cells, whereas C 4 pathway proteins were low or undetectable. The pattern of starch accumulation correlated with the localization of Rubisco, being highest in the bundle sheath cells and lowest in the mesophyll cells of organs having Kranz anatomy. In NAD-ME-type Kranz organs (leaves and cotyledons of S. laricina and leaves of H. gossypina) the granal index (length of appressed membranes as a percentage of total length of all membranes) of bundle sheath chloroplasts is 1.5 to 2.5 times higher than that of mesophyll chloroplasts. In contrast, in the NADP-ME-type Kranz organs (S. richteri leaves and cotyledons and H. persicum stems) the granal index of mesophyll chloroplasts is 1.5 to 2.2 times that of the bundle sheath chloroplasts. The mechanism of photosynthesis in these species is discussed in relation to structural differences.

Characterization of NADP-malic enzyme from two species of Chenopodiaceae: Haloxylon persicum (C 4) and Chenopodium album (C 3)

Kinetic and structural properties of NADP-malic enzyme (NADP-ME, E.C. 1.1.1.40) were analyzed from two members of the Chenopodiaceae family, Haloxylon persicum, an unusual C 4 NADP-ME type tree species native to Central Asia Deserts, and Chenopodium album, a C 3 weedy species. Two isoforms of the enzyme, with molecular masses of 67 and 72 kDa and p Is (isoelectric points) of 6.75 and 5.85, respectively, were found in crude extracts of H. persicum by western blots using an antibody against the 62 kDa isoform from maize leaves. In C. album, a C 3 plant, only one immunoreactive isoform, of 72 kDa was found, with an isoelectric point of 5.85. The 67 kDa isoform was purified from H. persicum shoots by precipitation with crystalline ammonium sulfate, anion-exchange, adsorption and affinity chromatographies. The 72 kDa isoform was purified from C. album in the same way, except that the adsorption chromatography step was omitted. The 67 kDa polypeptide of H. persicum was identified as a C 4 isoform based on its high specific activity, low K m values for malate and NADP, and characteristics of its pH optima. However, this isoform is very different in molecular mass and isoelectric point from the previously characterized C 4 isoform found in C 4 monocots and C 4 Flaveria species. The 72 kDa isoform from C. album has kinetic properties which are distinct from the C 4 isoform of H. persicum, and characteristic of the low activity constitutive form found in various plants.

Fuel resources for copper smelting in antiquity in selected woodlands in the Edom highlands to the Wadi Arabah/Jordan

Summary Near Feinan, in the area between the Wadi Arabah and the highlands of Edom, an analysis of the standing biomass was carried out on remnants of the woody vegetation used as fuel for copper smelting since the Early Bronze Age. The analysis provides biomass data for individual shrubs and trees as well as for one hectare. For the first time the amount of wood available from seven types of shrub- and woodlands is discussed in relation to different species spectra obtained from charcoal remains of five copper smelting periods. The preliminary quantitative data presented here provide the botanical basis for an interdisciplinary approach which relates human impact to the degradation of woodlands. For sixteen shrubs and trees from eight species the individual amount of wood was determined. Up to eight diameter categories, including fine twigs, were defined in order to obtain data on all the wood used as fuel. The highest amount of wood was found to be Tamarix jordanis with nearly 800 kg dried wood per plant. Medium sized trees of Acacia spp., Juniperus phoenicea, Pistacia atlantica and Quercus calliprinos yield approximately 150 to 500 kg wood. The dry weight of a typical Retama raetam or Haloxylon persicum shrub is 2 to 15 kg. For seven species, representative squares with pure stands up to one hectare were chosen, and releves were taken. The number of plants per hectare was counted as multiples of the individuals defined as typical for the species in that region. From these data, the amount of wood per hectare was calculated. The data can be interpreted as the maximum amount of wood available for fuel in each vegetation unit. Riparian thickets of Tamarix jordan is with 135 t dried wood per hectare were found to be the vegetation the most rich in energy. Also rather rich in wood are evergreen Juniperus phoenicea and sclerophyllous Quercus calliprinos woodlands. Rather little wood per hectare is produced by Haloxylon persicum and Acacia spp. open vegetation. While further physical and chemical properties of the woods are not yet known, dry density is discussed as a possible criterion for the selection of a particular wood as fuel. The dry density of wood of Olea europaea, Acacia cf. tortilis and Haloxylon persicum is nearly 1.0 g/cm 3 , that of Rhamnus spp. and Lycium shawii even 1.1 g/cm 3 . Pistacia atlantica, Quercus calliprinos and Retama raetam wood has a dry density of about 0.9 g/cm 3 . Juniperus phoenicea and Tamarix jordanis have 0.8 and 0.7 g/cm 3 , respectively. Moringa peregrina has only 0.4 g/cm 3 . Finally, archaeobotanical aspects of this work are pointed out. The use of vegetation by man in antiquity is discussed. The dominance of the highland species Juniperus phoenicea in charcoal spectra from the Bronze Age and its absence in later times is interpreted as indication of a climatically induced temporary depression of its area. On the basis of archaeological evidence, transportation as well as overexploitation can be excluded as explanations for this decline during Bronze age. On the other hand the total destruction of Tamarix stands near Feinan due to overexploitation during Iron Age and Persian Period is highly probable.

Charcoal remains from an Iron Age copper smelting slag heap at Feinan, Wadi Arabah (Jordan)

Charcoal remains were analysed from copper ore smelting at Khirbet en-Nahas, an Iron Age site in the region of Feinan between Wadi Arabah and the highland of Edom. For the first time, a section was dug into a stratified slag heap and separate charcoal samples were taken from each layer. Radiocarbon dates from the charcoal range from the 12th to the 9th century B.C. The main aim of this work was to find out whether the fuel species spectra change or remain constant over the period of metallurgical activity covered by this slag heap. Twelve samples totalling 2257 pieces amounting to 340.58 g of charcoal were analysed. The species composition is more or less the same in all samples. 14 species were identified. Approximately 50% of the material consisted of Tamarix species, 40% was Retama raetam, Phoenix dactylifera and Haloxylon persicum. Thus, the rapidly regenerating shrub vegetation within walking distance of the smelting place was used as fuel and remained unchanged during at least two to three centuries. Trees from the highland of Edom such as Juniperus phoenicea or Quercus calliprinos were not found here, although they were identified from Early Bronze Age sites a few kilometres up the wadis.

Plant life in the Rub' al-Khali (the Empty Quarter), south-central Arabia

SynopsisThe hyperarid climate of the Rub' al-Khali strongly conditions plant life in this subtropical hot desert. There is fossil evidence of a more humid climate here in late Tertiary and Pleistocene times and of a lakeforming phase as recent as 9000–6000 BP. Today rain may not occur for years in some parts, with annual means less than 25 mm, yet the extensive sands provide more scope for plant growth than do some rock and gravel tracts in less arid northern Arabia. The sand vegetation is characterised by very diffuse shrub communities led respectively by an endemic subspecies of Calligonum crinitum, the endemic saltbush Cornulaca arabica and, locally, by Haloxylon persicum. Cyperus conglomeratus, Dipterygium glaucum, Limeum arabicum, and Zygophyllum mandavillei are widespread associates. Sand-free gravel floors or salt flats, relatively small in extent, are nearly or entirely sterile. Tree forms are absent except for rare individuals on some borderlands. Floristic diversity is very restricted; only about 37 species (listed), of which hardly 10 are important in the vegetation, are recorded from an area of 500,000 km2. Annual plants are virtually absent, a situation contrasting sharply with that in Arabia to the N where more than half the desert species are therophytes.

GLC-Mass Spectroscopy of Distilled Alkaloids of Haloxylon Persicum1

Abstract GLC-Mass spectrometric study of the distilled alkaloids of Haloxylon persicum which gorws wild in Saudi Arabia reveals the presence of cotinine as a minor alkaloid as well as anabasine which is a major alkaloid and nicotine which is also a minor alkaloid. The presence of both anabasine and nicotine has been previously established by other means. The occurrence of cotinine in the plant furnishes a supporting evidence for the presence of nicotine in Haloxylon persicum.