Zygophyllum Species Research Articles

Spatio-temporal diversification pattern of Brinckia (Coleoptera: Tenebrionidae) in the Namib coastal belt

Beetles of the family Tenebrionidae, particularly those of the subfamily Pimeliinae, are highly diverse and abundant in desert ecosystems. The sensitivity of the many wingless species to geographical and ecological isolation makes them ideal candidates for studying effects of climatological and/or geophysical changes on organismal diversity. Our study focuses on Brinckia, the only genus of the subtribe Hypomelina adapted to coastal sand dune hummocks (nabkhas) and restricted to that environment along the Namib Desert and the transitional Namib south of the Orange River. Today, Brinckia appear to be common along the coast, albeit with different species, wherever the absence of shifting sand dunes enables the beach hummocks to form, mainly around Salsola and Zygophyllum species. Therefore, past diversification can probably be directly attributed to temporary extinctions of this habitat in certain coastal regions. The presumed center of origin and diversification of Brinckia is on the Gariep Karoo coastline between Port Nolloth and Lüderitz. Our molecular phylogenetic analysis suggests that the first split within Brinckia occurred ∼2.3 Ma, i.e., relatively recently, and may be associated with aridification that occurred at that time due to global climate change. However, subsequent speciation is more likely the result of the emergence of extensive dune fields, which may have been responsible for temporary habitat degradation in the supralittoral zone. More recent, recurrent and ongoing diversification since the mid-Pleistocene transition, as observed for tenebrionids along the coast of the Atacama and Peruvian deserts, is not typical of Brinckia and supports the stability of their coastal habitat despite glacial climate oscillations.

Protection against insect predation during fruit development: the role of fleshy fruit wings of three species of Zygophyllum in the cold desert of Central Asia.

Fruit wings serve various ecological functions, including facilitating wind dispersal, providing physical protection to seeds, and regulating seed germination. While many studies have reported the role of fruit wings in plants, little is known about their protective function during fruit development. In this study, winged fruits damaged by insects in natural populations of three Zygophyllum species (Z. potaninii, Z. lehmannianum and Z. macropterum) were investigated. We measured and compared the percentage of damaged winged fruits, seed set, seed mass, seed germination, and seedling growth of different insect herbivory categories. The results revealed that the percentage of winged fruits with damaged wings only (low predation) was significantly higher than that of with damaged both fruit wings and fruit bodies (high predation). Furthermore, winged fruits with low predation had significant higher seed set, seed mass, seed germination, and dry mass and relative growth rate (RGR) in the seedlings which grown from the seeds, than that from winged fruits with high predation. These results demonstrate that the presence of the fruit wings may provide protection for the seeds to alleviate harm from insect predation before dispersal. These findings provide new insights into the function of fruit wings and the reproductive strategies of desert plants.

Comparative plastome genomics, taxonomic delimitation and evolutionary divergences of Tetraena hamiensis var. qatarensis and Tetraena simplex (Zygophyllaceae)

The Zygophyllum and Tetraena genera are intriguingly important ecologically and medicinally. Based on morphological characteristics, T. hamiensis var. qatarensis, and T. simplex were transferred from Zygophyllum to Tetraena with the least genomic datasets available. Hence, we sequenced the T. hamiensis and T. simplex and performed in-depth comparative genomics, phylogenetic analysis, and estimated time divergences. The complete plastomes ranged between 106,720 and 106,446 bp—typically smaller than angiosperms plastomes. The plastome circular genomes are divided into large single-copy regions (~ 80,964 bp), small single-copy regions (~ 17,416 bp), and two inverted repeats regions (~ 4170 bp) in both Tetraena species. An unusual shrinkage of IR regions 16–24 kb was identified. This resulted in the loss of 16 genes, including 11 ndh genes which encode the NADH dehydrogenase subunits, and a significant size reduction of Tetraena plastomes compared to other angiosperms. The inter-species variations and similarities were identified using genome-wide comparisons. Phylogenetic trees generated by analyzing the whole plastomes, protein-coding genes, matK, rbcL, and cssA genes exhibited identical topologies, indicating that both species are sisters to the genus Tetraena and may not belong to Zygophyllum. Similarly, based on the entire plastome and proteins coding genes datasets, the time divergence of Zygophyllum and Tetraena was 36.6 Ma and 34.4 Ma, respectively. Tetraena stem ages were 31.7 and 18.2 Ma based on full plastome and protein-coding genes. The current study presents the plastome as a distinguishing and identification feature among the closely related Tetraena and Zygophyllum species. It can be potentially used as a universal super-barcode for identifying plants.

Comparative Chloroplast Genomics and Phylogenetic Analysis of Zygophyllum (Zygophyllaceae) of China.

The genus Zygophyllum comprises over 150 species within the plant family Zygophyllaceae. These species predominantly grow in arid and semiarid areas, and about 20 occur in northwestern China. In this study, we sampled 24 individuals of Zygophyllum representing 15 species and sequenced their complete chloroplast (cp) genomes. For comparison, we also sequenced cp genomes of two species of Peganum from China representing the closely allied family, Nitrariaceae. The 24 cp genomes of Zygophyllum were smaller and ranged in size from 104,221 to 106,286 bp, each containing a large single-copy (LSC) region (79,245–80,439 bp), a small single-copy (SSC) region (16,285–17,146 bp), and a pair of inverted repeat (IR) regions (3,792–4,466 bp). These cp genomes contained 111–112 genes each, including 74–75 protein-coding genes (PCGs), four ribosomal RNA genes, and 33 transfer RNA genes, and all cp genomes showed similar gene order, content, and structure. The cp genomes of Zygophyllum appeared to lose some genes such as ndh genes and rRNA genes, of which four rRNA genes were in the SSC region, not in the IR regions. However, the SC and IR regions had greater similarity within Zygophyllum than between the genus and Peganum. We detected nine highly variable intergenic spacers: matK-trnQ, psaC-rps15, psbZ-trnG, rps7-trnL, rps15-trnN, trnE-trnT, trnL-rpl32, trnQ-psbK, and trnS-trnG. Additionally, we identified 156 simple sequence repeat (cpSSR) markers shared among the genomes of the 24 Zygophyllum samples and seven cpSSRs that were unique to the species of Zygophyllum. These markers may be useful in future studies on genetic diversity and relationships of Zygophyllum and closely related taxa. Using the sequenced cp genomes, we reconstructed a phylogeny that strongly supported the division of Chinese Zygophyllum into herbaceous and shrubby clades. We utilized our phylogenetic results along with prior morphological studies to address several remaining taxonomic questions within Zygophyllum. Specifically, we found that Zygophyllum kaschgaricum is included within Zygophyllum xanthoxylon supporting the present treatment of the former genus Sarcozygium as a subgenus within Zygophyllum. Our results provide a foundation for future research on the genetic resources of Zygophyllum.

Transcriptomic and metabolomic analysis reveals the role of CoA in the salt tolerance of Zygophyllum spp

BackgroundZygophyllum is an important medicinal plant, with notable properties such as resistance to salt, alkali, and drought, as well as tolerance of poor soils and shifting sand. However, the response mechanism of Zygophyllum spp. to abiotic stess were rarely studied.ResultsHere, we aimed to explore the salt-tolerance genes of Zygophyllum plants by transcriptomic and metabolic approaches. We chose Z. brachypterum, Z. obliquum and Z. fabago to screen for salt tolerant and sensitive species. Cytological observation showed that both the stem and leaf of Z. brachypterum were significantly thicker than those of Z. fabago. Then, we treated these three species with different concentrations of NaCl, and found that Z. brachypterum exhibited the highest salt tolerance (ST), while Z. fabago was the most sensitive to salt (SS). With the increase of salt concentration, the CAT, SOD and POD activity, as well as proline and chlorophyll content in SS decreased significantly more than in ST. After salt treatment, the proportion of open stomata in ST decreased significantly more than in SS, although there was no significant difference in stomatal number between the two species. Transcriptomic analysis identified a total of 11 overlapping differentially expressed genes (DEGs) in the leaves and roots of the ST and SS species after salt stress. Two branched-chain-amino-acid aminotransferase (BCAT) genes among the 11 DEGs, which were significantly enriched in pantothenate and CoA biosynthesis, as well as the valine, leucine and isoleucine biosynthesis pathways, were confirmed to be significantly induced by salt stress through qRT-PCR. Furthermore, overlapping differentially abundant metabolites showed that the pantothenate and CoA biosynthesis pathways were significantly enriched after salt stress, which was consistent with the KEGG pathways enriched according to transcriptomics.ConclusionsIn our study, transcriptomic and metabolomic analysis revealed that BCAT genes may affect the pantothenate and CoA biosynthesis pathway to regulate the salt tolerance of Zygophyllum species, which may constitute a newly identified signaling pathway through which plants respond to salt stress.

A Comprehensive Review on Genus Zygophyllum

Objectives: This study aimed to make a broad review of the chemical constituents and biological activities of genus Zygophyllum. Methods: This review covers the peer reviewed articles between 1977 and August, 2018, retrieved from PubMed, Science Direct, Sci-Hub, Springer and Wikipedia Results: In traditional medicine, plants of genus Zygophyllum have been employed and utilized as anti-rheumatic, anti-gout, antidiabetic, anti-hyperlipidemic, antimicrobial, anti-oxidant, antihypertensive, antiseptic, anti-eczema and antidiarrheal. Zygophyllum species have been phytochemically studied leading to the identification of various classes of compounds including triterpenes, flavonoids, saponins, sterols, simple phenolic compounds, and esters. Biological studies on Zygophyllum species have also indicated various bioactive potentials including antioxidant, antidiabetic, antimicrobial antitumor and anti-inflammatory effects. The reported medicinal Zygophyllum species were selected and summarized on basis of their; geographical distribution, traditional uses, chemical constituents and biological activities. Conclusion: It would therefore be important to extensively investigate their phytochemicals and pharmacologically determine their activities for future drug discovery and development.

Taxonomic revision of Saudi Arabian <i>Tetraena</i> Maxim. and <i>Zygophyllum</i> L. (Zygophyllaceae) with one new variety and four new combinations

The genera Tetraena Maxim. and Zygophyllum L. (Zygophyllaceae) present different morphological characters, viz. growth habit, leaf features, flower traits and fruit shape, and have a high diversity of species in Africa, Australia and Asia. Six species of Tetraena [T. alba (L.f.) Beier & Thulin, T. coccinea (L) Beier & Thulin, T. decumbens (Delile) Beier & Thulin, T. hamiensis (Schwein f.) Beier & Thulin, T. propinqua (Decne.) Ghaz. & Osborne and T. simplex (L.) Beier & Thulin], and one species of Zygophyllum (Z. fabago L.) have been identified in Saudi Arabia, most of which grow in sandy soils and saline habitats as shrubs and herbs. One new endemic variety (T. alba var. arabica Alzahrani & Albokhari) along with four new combinations [T. alba var. amblyocarpa (Baker) Alzahrani & Albokhari, T. hamiensis var. qatarensis (Hadidi ex Beier & Thulin) Alzahrani & Albokhari, T. hamiensis var. mandavillei (Hadidi ex Beier & Thulin) Alzahrnai & Albokhari, and T. propinqua subsp. migahidii (Hadidi ex Beier & Thulin) Alzahrani & Albokhari] are proposed. Descriptions, illustrations, distribution maps and a key for identification of the taxa are presented. Conservation status has been proposed for the new variety and combinations.Bangladesh J. Plant Taxon. 25(1): 19-43, 2018 (June)

Adaptive Responses of Some Zygophyllum Species in Wadi Hagul, Egypt

Three species, Zygophyllum coccineum L., Zygophyllum decumbens Delile and Zygophyllum simplex L., (Zygophyllaceae) were collected from three localities of Wadi Hagul in Egypt to study their adaptive responses to different environmental conditions. Plant analyses (degree of succulence, water content, total pigments, proline, antioxidant enzymes, total phenols, ascorbic acid, hydrogen peroxide and malondialdehyde) were estimated to study their roles in the adaptive responses of those plants under their natural drought conditions. Results have revealed that xerophytes can further be divided into two groups depending on their drought tolerance strategies. The first group includes perennial plants (Zygophyllum coccineum and Zygophyllum decembens) that able to tolerate and resurrect following desiccation into photosynthetically active states in a short period of time, the other is the dessication avoiding group; annual or biennial plant (Zygophyllum simplex), which possess an improved water-storing organ, efficient water conduction within the plant body and/or a combination of these features. Moreover, plants in this group (true xerophytes) are thought to have a unique system to cope with stress tolerance, since they are able to defend their photosynthetic apparatus and other fragile cellular components from composite stresses in the harsh environments in which they are found.

Karyotype analysis and new chromosome number reports inZygophyllumspecies

Karyotypic study of eight populations belonging to two Zygophyllum species indicated chromosome numbers of Zygophyllum eurypterum (six populations) and Zygophyllum eichwaldii (two populations) were diploid (2n = 2x = 22) and tetraploid (2n = 4x = 44), respectively. The chromosome number of these species is reported for the first time. There were significant variations among populations in most chromosomes and karyotype characteristics. Cluster analysis based on chromosomal characteristics separated populations into two major groups. The first group included two populations of Z. eichwaldii (diploid populations), while the second group included six populations of Z. eurypterum (tetraploid populations). The chromosomes were mostly metacentric (m) and sub-metacentric (sm) in all populations. The Stebbins classification system grouped all populations in class B, considered a primitive class in this system. These results may provide useful information for Zygophyllum evolutionary and breeding studies.

Effect of heavy metals on plasma membrane lipids and antioxidant enzymes of Zygophyllum species

Background: Heavy metals are major environmental pollutant when they present in high concentration in soil and have toxic effects on growth and development of plants. Industrial activities result in heavy metal pollution of large areas of land, which greatly affects natural vegetation. Understanding the mechanism of how plants combat heavy metals adverse effects is hence of great importance. Materials and Methods: Two different localities were chosen; one locality was in the vicinity of gypsum factory and the other one was 25 km away from the factory. Two Zygophyllum species (Z. album and Z. coccineum) were naturally grown in the studied areas. The effects of soil heavy metal stress on shoot heavy metal concentrations, lipid peroxidation, antioxidant enzyme activities and the root plasma membrane (PM) lipid composition were analyzed. Results: Heavy metal concentrations and Lipid peroxidation increased in the shoot of both species grown in the polluted area. The activities of ascorbate oxidase (ASO), guaiacal peroxidase (GPX), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were increased whereas these of catalase (CAT) were decreased in both species under the polluted conditions. PM total lipids, phospholipids, glycolipids and sterols were decreased in Z. album and Z. coccineum as a result of the polluted soil. Heavy metal stress increased phosphatidylethanolamine (PE) and decreased phosphatidylinositol (PI) and phophatidylglycerol (PG), with no significant change in phosphatidylcholine (PC) in the root PM of both species. Phosphatidylserine (PS) decreased in the PM of Z. album whereas it increased in the PM of Z. coccineum under the pollution conditions. Heavy metal stress changed the composition and concentration of fatty acids of the root PM, resulting in increased sat/unsat ratio of both species. Conclusion: the results suggest that efficient antioxidant machinery and favorable PM lipid homeostasis are important to enable Zygophyllum species to withstand the prevailing heavy metal stress.

Seasonal diet preferences of black rhinoceros in three arid South African National Parks

AbstractBlack rhinoceros diet and browse availability was investigated in Augrabies Falls (AFNP), Karoo (KRNP) and Vaalbos National Parks (VNP) in South Africa. Rhino tracks were followed and 18,804 standard bite volumes recorded. Browse availability of each plant species was recorded by measuring 14,800 plants and calculating reachable browse volume. The diet comprised 51, 53 and 41 plant species in AFNP, KRNP and VNP, respectively, but three species accounted for more than 65% of the diet in each park, making diet less diverse than available browse in AFNP and KRNP. Browse availability explained 14%, 15% and 52% of diet selection in AFNP, KRNP and VNP, with consumption of most plant species significantly different from availability. A few plant species were so highly preferred that browsing intensities were unsustainable, while some common species were totally rejected. Pressure on the eaten browse averaged 4.4%, 14.5% and 1.3% annually of the volume in AFNP, KRNP and VNP. In the dry season, there was a two to sevenfold increase in browsing pressure on species with actively photosynthesizing tissues. A few key species, including Monechma and Zygophyllum species, were identified as potential early warning indicators of black rhino browsing impact.

Lipid composition and biological activity of extracts from Zygophyllum oxianum

Zygophyllum species (Zygophyllaceae) are widely distributed in Uzbekistan and used in folk medicine as antiinfectious, antirheumatic and antidiabetic means. Continuing our research on the chemical constituents of this genus [1,2], we have studied the lipid composition of the aerial parts of Zygophyllum oxianum Boriss. The yields of the total lipids were: leaves –0.75%, stems –0.33% and fruits –0.49% from fresh weight of organ. Phospholipids (PL) are presented by 9 classes, from them phosphatidylcholine is dominating (leaves –55.8%, stems –56.4%, fruits –63.7% from sum of PL). The study of antimicrobial activity against several bacterial strains and fungi showed that the n-butanol extract from all aerial parts exhibits significant activity against Candida sp. but only weak antibacterial activity. In cytotoxicity assays against 5637 human urinary bladder cells the n-butanol extract showed only weak activity. Otherwise the chloroform-methanol (2:1) extract of steams and leaves has a remarkable cytotoxicity against 5637 cells with an IC50 value of 6.2µg/ml, but only weak antibacterial and antifungal activity. The chloroform-methanol extract (2:1) of the fruits was less toxic (IC50 value: 37.6µg/ml).

Genetic diversity among Zygophyllum (Zygophyllaceae) populations based on RAPD analysis

Zygophyllum species are succulent plants that are drought resistant and/or salt tolerant, growing under severe, dry climatic conditions. Despite their importance and abundance in the Mediterranean and Middle East regions, there is little information concerning molecular variations among species of this genus. Genetic diversity was assessed, using RAPD primers, of 12 populations of Z. coccineum, Z. album and Z. aegyptium collected from various locations in Egypt and Saudi Arabia. Yong leaves were used for DNA extraction. Genetic distances were calculated using Nei's method. A dendrogram was constructed based on the similarity data matrix by unweighted pair group method using arithmetic averages cluster analysis. Analysis with RAPD markers revealed genetic variation between and within populations of Zygophyllum. Zygophyllum coccineum showed higher levels of genetic variation and more unique alleles than the other species.

Phylogenetic relationships, character evolution and biogeography of southern African members of Zygophyllum (Zygophyllaceae) based on three plastid regions

The plastid coding rbcL and non-coding trnLF regions of 53 of 55 southern African Zygophyllum species were sequenced and used to evaluate the phylogenetic relationships within the southern African representatives of the genus. Published sequences of the same gene regions of Australian, Asian and North African Zygophyllum species were included to assess the relationships of the species from these regions to the southern African species. The addition of Z. stapffii from Namibia, found to be conspecific with Z. orbiculatum from Angola, lead to a greatly resolved tree. The molecular results were largely congruent with a recent sectional classification of the southern African species and supported their subdivision into subgenera Agrophyllum and Zygophyllum. Reconstruction of the character evolution of capsule dehiscence, seed attachment and seed mucilage showed that these characters allowed a division of southern African species into the two subgenera but that this could not be applied to species occurring elsewhere. Other morphological characters were found to vary and unique character combinations, rather than unique characters, were found to be of systematic value in sectional delimitation. The study suggests that repeated radiations from the horn of Africa to southern Africa and Asia and back lead to the present distribution of the taxa in the subfamily Zygophylloideae. Although this study supports some of the recent taxonomic changes in the group, the unresolved relationships between the proposed genera Tetraena and Roepera and those retained as Zygophyllum species suggest that changes to the taxonomy may have been premature.

Pollen morphology, leaf surfaces, mycobiota diversity and leaf spots of three species ofZygophyllumgrowing along Cairo‐Suez desert road, Eastern (Arabian) desert in Egypt

AbstractThree native species ofZygophyllum:Z. coccinumL.,Z. decumbensL.and Z. simplexL. (Zygophyllaceae) have been investigated morphologically, palynologically and mycologically. Twenty‐two fungal species belonging to 11 genera were collected from leaf surfaces (11 genera and 22 species) and anthers/ pollen grains (7, 13) ofZygophyllum coccinum, Z. decumbens and Z. simplexon Czapek‐Dox agar at 25 °C. Fungal diversity of the two microhabitats is basically similar and the most prevalent fungi wereAlternaria alternata/A. phragmospora, Cladosporium cladosporioides/C. herbarumandUlocladium botrytis/U. consortiale.Alternaria alternata,Cladosporium cladosporioidesandC. herbarum‐leaf spots were rarely recorded in the three studied plant species.Leaf lamina size and sculpture of the studied taxa almost seem to be the most reliable factors of the fungal biodiversity on the studied plant species. On the other hand, reticulate‐micro reticulate pollen type is the only pollen type recorded in the present study which reflects that the very narrow range of spectrum of fungal biodiversity between the studied plant species. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Phytochemical study of the aerial parts of Zygophyllum geslini

Zygophyllum geslini Coss. (Zygophyllaceae), traditionally used as antidiabetic [1], was collected in the Algerian Central Sahara. From a methanolic extract of the aerial parts, a crude saponin mixture was obtained and submitted to successive solid/liquid preparative chromatographic methods, i.e. VLC, MPLC over silica gel and RP-18. Five saponins were isolated and purified, and their structures were established mainly by 600MHz 2D NMR techniques (COSY, TOCSY, NOESY, HSQC, HMBC) and mass spectrometry. Three new triterpene glycosides were identified as 3-O-α-L-rhamnopyranosyl-(1(→2)-α-L-arabinopyranosyl-(1(→2)-β-D-glucuronopyranosyl-urs-20(21)-en-28-oic acid-28-O-(2-O-sulfo-β-D-glucopyranosyl) ester, 3-O-(2-O-sulfo-β-D-glucuronopyranosyl)-urs-20(21)-en-28-oic acid-28-O-(2-O-sulfo-β-D-glucopyranosyl) ester, and 3-O-(2-O-sulfo-β-D-glucopyranosyl)-quinovic acid, together with the known zygophylosides E and G. Comparing the results obtained with different Zygophyllum species [2], the presence of the ursane-type aglycone and the sulfonyl moiety in these molecules may represent chemotaxonomic markers of this genus.

Three new species of <i>Zygophyllum</i>(Zygophyllaceae) from Namibia and Northern Cape, South Africa

Three new species of Zygophyllum L. from the lower Orange River area in Namibia and Northern Cape, South Africa are described, namely, Z applanatum Van Zyl, Z. hirticaule Van Zyl and Z pterocaule Van Zyl.

Two new species of <i>Zygophyllum</i> (Zygophyllaceae) from the Western Cape, South Africa

Two new species of Zygophyllum L. from the Western Cape are described, namely, Z. fuscatum Van Zyl from the coastline between Betty’s Bay and De Hoop Nature Reserve and Z botulifolium Van Zyl from the Tanqua Karoo.

English

13 Eichler, Hansjoerg (Australian National Herbarium, CSIRO, C.P.O. Box 1600, Canberra, A.C.T. 2601) 1990. Four new species of Zygophyllum (Zygophyllaceae) and one lectotypi(ication. Telopea 4(1): 13-17. The new species Zygophyllum angustifolium, Z. confluens, Z. emarginatum and Z. simile are described and their general distribution outlined. Representative specimens from New South Wales localities are listed. A lectotype of Z. ammophilum F.Muell. is designated. The names of four new species of Zygophyllum need validation in order to be used in the forthcoming 'Flora of New South Wales'. The brief Latin descriptions of the salient features and the designation of the holotypes required by the International Code of Botanical Nomenclature, slightly more elaborate English descriptions, an indication of the distribution, and notes on distinctive characters of the species with which the new species had hitherto been confused, are provided below. As this paper is a precursor to the 'Flora of New South Wales', only specimens examined from localities in New South Wales are listed. 1. Zygophyllum angustifolium H. Eichler, sp. nov. Fruticulus tenuis, plerumque 30-60 cm altus, glaber. Folia petiolata, unijugata; foliola linearia vel peranguste oblongi-elliptica, 10-30 mm longa, 2-4 mm lata, ad basim constricta, articulata, ad apicem acuta. Petala 4, flava, anguste obovata vel elliptica, 4-8 mm longa, sepalis 1/4-1/3 plo longiora. Stamina 8; filamenta subulata, exalata, haud appendiculata. Discus 4-partitus; lobi disci discreti, carnosi, semiorbiculares, margine papilloso. Capsula obconica, 6-9 mm longa, tetragona, 4-cellularis, apice truncata; cellula 1vel 2-seminalis. HOLOTYPUS: Hj. Eichler 20655: South Australia. Gawler Ranges. Yandinga Gorge: in valley near waterfall c. 35 km north-north-east of Minnipa. 32 0 33'S, 135 0 20'E. 14 Oct 1969 (CANB 385209). ISOTYP!: AD, B, CANB, G, K, L, MEL, NSW, PERTH, US. Slender, glabrous shrublet, usually 30-60 cm high, sometimes scrambling over taller plants and then reaching 150 cm or more. Leaves petiolate, with one pair of leaflets; leaflets succulent, linear to narrowly oblong-elliptic, 10-30 mm long, 2-4 mm wide, narrowed and articulate at base, acute at apex. Petals 4, pale yellow, narrowly obovate to elliptic, 4-8 mm long, about %-1/3 times longer than sepals. Stamens 8; filaments subulate, c. 3 mm long, without wings or appendage; anthers oblong, c. % mm long. Disc 4-lobed; lobes free, succulent, semicircular, with papillose margin. Ovary broadoblong, c. 2 mm long, truncate at apex, glabrous; style subulate, c. 1.5-2 mm long; stigma minutely 4-lobed. Fruiting pedicels 8-25 mm long. Capsule obconical, 6-9 mm long, 4-angled, 4-celled, truncatoe at apex, with 1 or usually 2 seeds per cell; style persistent, 1.5-3 (rarely 4) mm long. Southern mainland Australia: Western Australia (Eucla), South Australia (Nullarbor, Gairdner-Torrens Basin, Flinders Range, Eastern Region, Eyre Peninsula, Northern Lofty, Murray, northern Yorke Peninsula), New South Wales (South Far Western Plains), and far north-western Victoria. Volume 4(1): 13–17 Publication Date: 26 September 1990 dx.doi.org/10.7751/telopea19904913 TELOPEA Journal of Plant Systematics Til. Ro)'al BOTANIC GARDENS 6 DOPII(liPi Tmst plantnet.rbgsyd.nsw.gov.au/Telopea • escholarship.usyd.edu.au/journals/index.php/TEL· ISSN 0312-9764 (Print) • ISSN 2200-4025 (Online)

Phenology, Pigment Content and Diurnal Change of Proline in Green and Senescing Leaves of Three Zygophyllum Species

Phenology, pigment content, succulence ratio and the diurnal changes of water and proline contents were investigated in green and yellow leaf parts of Zygophyllum album , Z. decumbens and Z. coccineum . Phenological patterns and the leaf area index were followed monthly during 1988. Pigment content, succulence ratio and the diurnal change of water and proline contents were investigated under natural environments in August. The leaf area index curves of the three species showed the highest values towards the end of the rainy season. The yellow leaflets and petioles of Z. album showed higher fresh and dry weights than the corresponding green ones. On the contrary, the green leaflets and petioles of Z. decumbens and Z. coccineum showed higher fresh and dry weights than the yellow ones. With the exception of shrivelled leaflets of Z. album , the leaf parts of the species investigated showed high succulence ratio. Phenology and the pigment content results support the concept that the three species undergo leaf senescence followed by shedding in the dry season. The importance of chlorophyll-dependent proline biosynthesis was clarified. The petioles of Z. decumbens and Z. coccineum showed higher proline content than the leaflets. Most leaf parts of the investigated species showed diurnal change of water and proline contents. Irrespective of the species, the relationship was negatively correlated in the green leaflets, the green and yellow petioles. This implies that the three species, although from two different habitats, showed a confirmed generality of proline accumulation, but in different magnitudes by the green and yellow (senescing) leaf parts as a response to water deficit.